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Answered by: Environmental Scientist
09 December 2011 13:25

Another excellent BBC GCSE Bitesize website has some helpful information on flooding here -

http://www.bbc.co.uk/schools/gcsebitesize/geography/water_rivers/river_flooding_management_rev1.shtml

Answered by: Environmental Scientist
09 December 2011 13:38

There are many engineering solutions that can be implemented to stop or at least reduce flooding. Such as coastal sea defences, river levees etc.

However afforestation or replanting vegetation can also help and is generally more achievable (it's cheaper) for developing countries to do!

Answered by: Environmental Scientist
09 December 2011 13:26

Government information can be found on the directgov website -

http://www.direct.gov.uk/en/HomeAndCommunity/WhereYouLive/FloodingInYourArea/DG_10014599

However, in a flooding emergency you should always follow local weather and government advice.

Answered by: Environmental Scientist
09 December 2011 13:48

We can predict certain phenomena, such as increased seismic activity and weather disturbances, to a certain extent but we cannot generally predict disasters. Even methods to predict the natural phenomena (such as volcanoes and earthquakes) isn't 100% accurate!

Answered by: Environmental Scientist
09 December 2011 14:03

2 separate but excellent questions!

Tsunami – Tsunamis cannot be prevented but there are some mitigation strategies that can be implemented but generally evacuation is key to avoid mass fatality.

http://www.ess.washington.edu/tsunami/general/mitigation/mitigation.html

Human Factors – The area human activity has the greatest impact on disasters is in the meteorological world – weather! Climate change, with the associated arguments of the exact implications humanity is having on that, has changed our weather patterns and the frequency of extreme events.

Answered by: Environmental Scientist
09 December 2011 13:58

Not always. There are such things as hotspots - Hawaii is the perfect case study.

http://hvo.wr.usgs.gov/volcanoes/

Earthquakes can also occur on fault lines no longer active and for more man-made reasons (such as subsidence).

Answered by: Electronic engineer
18 December 2011 18:12

Most cars come with a user manual which should contain the manufacturers (e.g. Ford, BMW, VW) recommendations of dealing with winter driving conditions such as engine antifreeze, winter engine oil, winter screen wash, window de-icing, battery maintenance and the types of tyres that can be used in cold climates to increase grip.

Answered by: Planetarium Presenter
23 December 2011 11:58

There are a few simple things we can do to prevent pipes from becoming frozen.

The main ones are to insulate the pipe - this not only helps reduce heat losses if it's a heating or hot water pipe thus saving you heating bills, but it slows down how fast the pipe cools.

Ensure you run your heating regularly, even if you're not at home to keep the temperature of the house above 0 degrees celcius.

Further suggestions are given by Scottish Water, including what to do if the pipes do freeze: http://tinyurl.com/dyk5wlc

Answered by: Geology & Geophysics PhD student
04 October 2011 22:28

We cannot predict earthquakes well in advance because they do not produce a signal that we can detect. We have a good understanding of where earthquakes are likely to occur, from historical information and because we understand how plate tectonics work. However, predicting when they will occur, is not possible. Often a large earthquake is preceded by a number of smaller earthquakes, but these only occur shortly before the large event and do not allow for enough time to alert the local population.

Answered by: Geology & Geophysics PhD student
06 October 2011 21:18

Earthquakes occur all the time all over the world, both along plate edges and along faults. The earth's crust (the outer layer of the planet) is made up of several pieces, called plates. The plates under the oceans are called oceanic plates and the rest are continental plates. The plates are moved around by the motion of a deeper part of the earth (the mantle) that lies underneath the crust. These plates are always bumping into each other, pulling away from each other, or past each other. The plates usually move at about the same speed that your fingernails grow. Earthquakes usually occur where two plates are running into each other or sliding past each other. Faults are cracks in the earth where sections of a plate (or two plates) are moving in different directions. Faults are caused by all that bumping and sliding the plates do. They are more common near the edges of the plates.

Answered by: Electronic engineer
01 November 2011 14:42

The magnitude of earthquakes is measured on a seismogram using the Richter scale invented by Charles F Richter in 1934. It is the largest amplitude of the seismic wave recorded for the earthquake. Note: Richter magnitudes are logarithmic scale (base 10) so for each whole number, the amplitude of the ground motion is 10 times i.e. 5 is 10 times the size of 4 on the Richter scale. http://www.bgs.ac.uk/discoveringGeology/hazards/earthquakes/HowWeMeasureThem.html

Answered by: Geology & Geophysics PhD student
12 October 2011 13:29

The largest earthquake recorded was a magnitude 9.5 on the richter scale, at Valdivia, Chile in 1960. The third largest is the Boxing day (2004) off the coast of Sumatra and that registered 9.1 on the richter scale. There is some bias towards more recent events, as we have a much wider network of seismometers. It is possible that prior to the development of seismometers there were even larger events, but they have simply not been measured.

Answered by: Professor of Earth Sciences
06 October 2011 12:48

Earthquake sizes are usually reported using the Richter magnitude scale. This scale was originally invented by Charles Richter so that different earthquakes could be compared; and he based this scale on the amount of shaking (the size of the ground waves) recorded by a seismometer at a particular distance from the earthquake centre. Today, scientists use several different ways to measure 'magnitude'. All of these estimate the amount of energy released in the earthquake, and since the amounts of energy release can be so large, the magnitude scales are logarithmic: so a magnitude 8 earthquake releases about 32 times more energy than a magnitude 8 quake.

There is a lot more on this on the US Geological Survey pages: http://earthquake.usgs.gov/learn/glossary/?termID=118

Answered by: Electronic engineer
01 November 2011 14:52

Earthquakes are when there is a sudden release of strain energy in the Earth's crust resulting in waves of shaking that humans can feel & can cause damage to buildings if powerful enough. As for predicting earthquakes there is currently no known way to predict them. There is some useful information on this page: http://earthquakes.bgs.ac.uk/education/faqs/faq_index.html

Answered by: Soil Scientist
13 November 2011 13:30

Hi Tina. At the moment there is no reliable way to predict an earthquake, because we have no way of measuring the buildup of pressure beneath the ground. We can look at where earthquakes are likely to occur, on major faults between the continents (e.g. the San Andreas fault, California) and see how long it was since the last earthquake, compare this with the rate of movement on the fault and the frequency of earthquakes there over history, and that way estimate roughly when we might expect the next one - but it is all guesswork.

Some scientists think that there are geochemical and other environmental changes that can occur before an earthquake, but no good evidence has been found to turn these into reliable predictors. The problem is that every earthquake occurs in a different place, with different geology, so the precursor signs - if they do occur - will always be slightly different.

Answered by: Electronic engineer
19 October 2011 14:54

Very likely! Minor earthquakes happen quite a lot in the UK in fact according to the British Geological Surveys web site there was one today at 02:32 in Tuxford, Nottinghamshire, it was of a fairly low magnitude of 1.6 on the Richter Scale. The last significant earthquake was at 00:56:47.8 on 27/02/2008 in Market Rasen, Lincolnshire and measured a mighty 5.2 on the Richter scale. These significant earthquakes have occurred approximately every 1-2 years over the last 40 years.

Answered by: Geology & Geophysics PhD student
13 October 2011 10:37

Hi Clare! Here is the link to a website that has an easy to understand explanation to why earthquakes happen. It also has a little experiment which you can do to help you understand them too. http://www.geo.mtu.edu/UPSeis/why.html

Answered by: Soil Scientist
13 November 2011 13:25

The solid surface of the Earth is always moving, because, underneath, the rocks are so hot that they flow about like water boiling in a pan (except much much more slowly). The hot moving rocks beneath drag the cold, solid surface rocks with them. However, because the surface is solid it doesn't move easily - try pushing two bricks together! So, over time, the pressure builds up more and more, until it is greater than the strength of the rocks can bear. When this happens, the rocks suddenly break and 'snap' past each other to release the pressure (imagine pressing the bricks together so hard that they crack, or suddenly slip past each other). This sudden movement shudders right through the Earth's surface away from the point where the break happened, and we feel it on the ground as the shaking of an earthquake.

Answered by: Professor of Earth Sciences
06 October 2011 12:40

A short answer would be no! Earthquake scientists use the word 'prediction' to mean that we can say when, where and how large an event will be. To be useful, a prediction must be able to specify the location and timing very precisely - otherwise it is nothing more than a statement of the obvious. ("There will be an earthquake somewhere on Earth in the next hour..." is not a prediction!). In some rare cases, we might be lucky to recognise a pattern of behaviour leading up to an event which then allows a prediction, but this is going to be the exception and not the rule. In many ways, movements on faults (and earthquakes) are as predictable as the snapping of an elastic band: if you have a hundred elastic bands and you stretch them one by one, they will all eventually snap. But they won't all snap after the same amount of stretching. So, geologists can give you a probability that a particular fault might break at a certain point, based on their measurements of previous breaks - and these probabilities, and how well we know them, will vary from fault to fault, and from place to place. In the future, we will get a lot better at estimating these probabilities - but we will still not be able to predict precisely when the next earthquake will happen in a particular place.

Answered by: Geology & Geophysics PhD student
19 October 2011 17:26

It is unlikely that we will be able to prevent earthquakes, but it is likely that in some instances (by no means all) we might be able to minimise the damage caused by an earthquake.

We can never stop an earthquake from happening (or that is my opinion at least). The forces driving earthquakes are so large, it is very unlikely we'll be able stop one. However, technology in a whole load of areas is ever improving, which would mean the damage caused by them might be significantly minimised. In the future, we hope to be able to predict earthquakes better and give people much more forewarning of the likelihood of a large event. We also know (and are discovering more and more) areas that are more susceptible to earthquakes and we can prepare those people living there. Better building infrastructure and better building planning can minimise the damage. Training people to know what to do in the event of an earthquake is also hugely important. I know San Francisco (and probably large parts of California) send all their school teachers on courses that tell them what to do in the event of an earthquake at school, in order to help them & their school survive an earthquake.

I don't think we can prevent disasters, but we can, in some instances, reduce the damage they cause by understanding them better. That is why research into them is so important!

Answered by: Environmental Scientist
20 October 2011 11:37

Many countries have earthquake proof building designs and standards. They are commonly mandated for new buildings in a lot of developed countries that experience a large volume and/or high magnitude quakes (such as Japan or the US). However, in poorer areas, standards are not imposed and this is one of the many reasons the impacts from earthquakes can be so devastating in these areas. Specifically, in Europe, we have EuroCode 8, which applies to all new builds in seismic regions.

There is also evidence that from Ancient times seismic design features have been incorporated into building constructions. There is evidence that materials and structural design were considered by Architects prior to construction, especially in the Med. There is currently debate about certain features in Pompeii and Ercolano, the famous towns destroyed by the AD79 eruption of Vesuvio, being specifically designed to withstand the frequent earthquakes experienced there.

Answered by: Environmental Scientist
20 October 2011 12:56

The effect on polar bears is really quite sad! This is a good website to use - http://www.polarbearsinternational.org/polar-bears/bear-essentials-polar-style/human-interaction/climate-change (you can also do online adoptions and other things to support the cause).

To summarise, increased temperatures is melting sea ice (the whole global warming debate is another issue!) and it’s this change that affects not only the habitat for the bears but also their prey stocks! Seals, for instance, need the sea ice to reproduce, as this sea ice melts, the seals cannot reproduce. This is reducing the numbers of food available for the bears, especially the cubs. Polar bears also require sea ice for activities such as mating and rearing young, so when this melts it also changes and alters these activities. You can see how interrelated everything is! There have also been incidents of polar bears drowning; they can only swim so far!

However, the answer is not clear cut (as with most environmental issues). In some areas there have been noted declines in population, whereas in other areas, numbers have remained but distribution has altered.

Answered by: Soil Scientist
15 November 2011 14:13

Hi Tina. Firstly, yes, we are likely in a natural warm 'interglacial' period between the last Ice Age and another future one, assuming that the pattern of Ice Ages that we have seen in the last million years or so continues. In the sense that the Earth's climate has varied continuously and by large amounts over geological time, then climate change is very real. However, 'man-made' climate change is also very real too. Since the industrial revolution, when we started burning coal and oil in large quantities, the amount of carbon dioxide in our atmosphere has shot up. Our knowledge of atmospheric physics tells us that this should cause increased temperatures by trapping more of the sun's heat near the surface. We are now seeing, in measurements from all over the world, signs of that increase, over and above what we might expect from 'natural' variations in temperature.

Answered by: Head of Education Services & Continued Learning, Royal Meteorological Society
01 November 2011 14:04

Yes ... but please dont call it 'global warming' - 'climate change' is a much more accurate term, as there is so much more going on than warming (in fact, a few, localised places are cooling). But yes, people are adding greenhouse gases to the atmosphere and the net effect on the whole climate system is to cause the climate to change.

Answered by: Soil Scientist
14 November 2011 21:13

The short answer is yes, assuming you mean periglacial regions in general and don't have a specific feature (e.g. pingos) in mind. The region of land in the Arctic known where permafrost exists is very sensitive to a warming climate. Most worryingly, permafrost locks up a large amount of carbon and methane in the ground. When/if it melts, this may be released into the atmosphere, greatly increasing the levels of greenhouse gases and accelerating climate change, which will melt greater amounts of permafrost, releasing more gases... - a process known as positive feedback. Not good.

Answered by: Environmental Scientist
20 October 2011 13:13

Hurricanes and typhoons are essentially the same thing; they are also called cyclones. Essentially, the name is dependant on which part of the world they are in. All terms mean tropical cyclone, but generally, the term Typhoon is used by the Japanese, Hurricane by the Americans and Cyclones by countries around the Indian Ocean.

The textbook definition for a tropical cyclone is “a system of thunderstorms that shows a cyclonic rotation around a central core or eye. A tropical cyclone is a generic term for a storm with an organized system of thunderstorms that are not based on a frontal system.”

Whirlwinds, or more commonly known as tornadoes, are the vortex of wind (rotating column of air), commonly seen in disaster movies!

Answered by: Geology & Geophysics PhD student
04 October 2011 21:23

Tsunamis are caused by a number of phenomenons. Generally they are caused by earthquakes, less commonly by submarine landslides, infrequently by submarine volcanic eruptions and very rarely by a large meteorite impact in the ocean. They are a result of the displacement of very large volumes of water, so can occur in oceans but also in large lakes. The most common scenario is a tsunami resulting from an earthquake, as this causes the sea floor to deform in a very short space of time and causes the overlying water to be displaced. A large earthquake has to occur in order to cause the movement required, so they are often associated with earthquakes that result from the movement of plate boundaries.

Answered by: Environmental Scientist
20 October 2011 13:30

In short, no!

Out at sea, tsunamis are hardly noticeable; it is to coastal communities that they are a threat. As tsunamis approach the shoreline, the gradient of the sea bed is inclined; this slows the base of the tsunami down but the tops are still moving fast. This makes them grow in energy and height (in brief). As they impact with the shore, any structures around will reduce the speed and provide physical barriers to SOME EXTENT, however, they can still come far inland before that happens!

General advice is to move to high ground and avoid the tsunami. But there are instances where mitigation strategies have been attempted; Afforestation, offshore blockers have been trialled. Success is debatable. Notable examples have been Japan and other Pacific-based countries.

Answered by: Geology & Geophysics PhD student
24 October 2011 12:55

There are a number of ways in which we can determine where fault lines are. The reality is that often they are found by chance!

Large scale faults - often expressed on the surface and air photographs taken from a plane or satellite can show, clearly, where a fault is. Have a look at this image of the St. Andreas Fault in California http://scrippsnews.ucsd.edu/Releases/?releaseID=736.

Seismic modelling - where a number of seismometers are placed on the ground to see the arrivals of earthquake events. The data is then modelled and can reveal the location of a new fault. Often faults have no expression on the Earth's surface and this is the only way we can see that they exist. It is a technique that allows us to "see" below the Earth. The boundaries of tectonic plates are associated with faults and we look in areas of known activity for more faults.

Answered by: Postdoctoral researcher in Electrical engineering
13 June 2011 08:19

Hi/

A rainbow is caused by an optical effect known as refraction (this means the bending of light).

The first thing to realise is that the whiteish/yellow light that the sun (or light bulbs) give out is actually made up of light of all the different colours which then add up to give the white look.

The second thing to know is that light moves differently through different objects for this reason when light moves between two different objects it can bend (this is called refraction). A good demonstration of this can be done in your kitchen using a glass of water and a pencil. Firstly you half fill a glass with water and then stand a pencil up in it, if you then look at the water level it looks like the pencil bends as you go from the air to the water.

As for rainbows forming, around a rainstorm there are lots of water droplets in the air so as the light travels through them it will bend in a similar way. As the white light from the sun is really made up of all the colours these will all bend and the amount they bend will depend on the colour allowing the colours to spread out forming a rainbow.

Answered by: Environmental Scientist
20 October 2011 14:17

See this - http://geology.com/records/highest-mountain-in-the-world.shtml

Answered by: Development Manager
09 October 2011 17:33

You have asked a good question. Tides are affected by two sources - the sun and the moon. You may have heard of "spring" tides - which don't just happen in the springtime, but whenever the sun and moon are aligned around the earth - either on the same side - or on opposite sides. The gravitational pull can be thought to "pull" the water towards the moon and sun. And so, when the sun and moon are aligned, this gives the highest tides. You always get a symmetrical bulge of water on either side of the earth, and as the earth rotates, this provides effectively two tides a day. When the sun and moon are pulling in different directions (imagine a 2D picture of the earth - and in the previous example, the sun and moon were either on the right of the earth, or one on the left and one on the right), then in the current example, we might have the sun on the right, and the moon "above" - and this way their gravitational forces are not "pulling" together, and we get the smallest tides - or "neap" tides - often referred to as neaps (not to be confused with your vegetables!

Answered by: Geologist & Hydrogeologist
04 October 2011 14:24

By weight, iron is the most common element. It is in most rocks, as part of the minerals that make up rocks. The mantle of the earth contains most of the mass, and is made up of semi liquid minerals with a high concentration of iron.

Answered by: Electronic engineer
28 October 2011 15:04

The most abundant elements in the Earth's crust are Oxygen 46.6% & Silicates 27.7%. For more information check out this website: http://hyperphysics.phy-astr.gsu.edu/hbase/tables/elabund.html

Answered by: Head of Science, St Pauls School, London
28 October 2011 14:38

The most common form of hydrogen has mass number 1. However there is a small amount (about 1 atom in 6000) of naturally occurring deuterium - a heavy isotope of hydrogen with mass number 2. Tritium, hydrogen with mass number 3, is radioactive and decays into helium-3 so has to be generated in nuclear reactors.

Answered by: Soil Scientist
15 November 2011 16:42

Hi Mel. The oldest fossils are of bacteria in rocks that are around 3 billion (thats 3,000 million) years old. Single bacteria are microscopic, but they grew in colonies which created large mushroom-shaped mounds called stromatolites, which are the fossils we can recognise. Modern bacteria create the same forms under the right conditions - look up 'Shark Bay, Australia' on the internet. The oldest fossils of larger creatures, like sponges, are up to 1,000 million years old, but the fossils of recognisable animals (things like horseshoe crabs and molluscs) do not appear in rocks older than about 540 million years. That is still very old though! Fossils of birds and mammals like those we see all about us today did not appear until less than 65 million years ago, and humans did not appear until the last 1 or 2 million years. That is still 500 times longer than human history since the time of Jesus Christ.

Answered by: Geology & Geophysics PhD student
04 October 2011 22:37

This is a geological process that affects rocks in deserts. In the heat of the day, the rock expands, but as temperatures drop at night the rocks cools and contracts. The repetition of this process, weakens the outer layers of the rock and they peel off, much like the layers of an onion.

Answered by: Environmental Scientist
20 October 2011 14:12

A good question! In the shortest (but widest terms) it is the study and application of all sciences related to Planet Earth.

Answered by: Geology & Geophysics PhD student
04 October 2011 22:18

There are two main theories about dinosaur extinction. The first proposes that a large meteorite impact (Chicxulub crater) to the Earth at about 65million years ago, on the Yucatan peninsula of Mexico, resulted in a large amount of dust and debris being thrown up into the atmosphere. This reduced the amount of sunlight reaching the Earth. In addition, the impact could have caused large scale fires, which would further increase the amount of gases in the atmosphere. This would result in plants not getting the energy they require for their survival and would die off. Dinosaurs would therefore not have enough food to survive and also die off. There is a large crater in the Yucatan Peninsula, which is how the theory originally came about. Large amounts of the rare element iridium were found at the site of crater. It is not found in large abundances on the Earth and it’s origin is thought to be extraterrestrial. Since, it has been found all over the World in geological deposits of the same age. Scientist believe that the source of it in these rocks must be the Chicxulub impact. As the timing of the impact is very close to the extinction of dinosaurs, it is thought to be a potential cause for the extinction of dinosaurs. The alternative theory suggests that a large igneous province (a very large scale volcanic eruption), in northern India caused a large volume of volcanic gases to be released into the atmosphere, causing Global Warming and blocking sunlight from the Earth. A final theory, though somewhat less supported, is that Dinosaurs were not able to evolve and adapt to the changes in the Earth over time (evolution of the plants they fed on, for example) and so slowly became extinct. It is likely that no single event caused the extinction of dinosaurs, but that a combination of events led to their demise.

Answered by: Soil Scientist
14 November 2011 21:31

Absolutely mining is within the Earth Sciences, although it also comprises a large body of specialist engineering too. Its an applied earth science, if you like - like oil prospecting. Check out the wikipedia entry on the Royal School of Mines, now the Earth Sciences department at Imperial College, London.

Answered by: Geology & Geophysics PhD student
24 October 2011 12:28

Hi Gav! In short, we don' know!! There are a number of theories, but there is not enough evidence to prove/disprove any of the proposed ideas. We think that studying the ancient magentic field might be able to tell us more about it. Follow the blog of the lab where I work at, to see how we are doing at answering questions about the Earth's magentic field http://www.geomagnetism.org/ I work on rocks themselves to find out the answers, but other people model the earth's interior to find out what that might be able to tell us. For a very cool animation, see this http://es.ucsc.edu/~glatz/geodynamo.html Finally, the USA geological survey has a really good web page, if you want to know more about the Earth's magnetic field! http://geomag.usgs.gov/faqs.php

Answered by: Geology & Geophysics PhD student
06 October 2011 21:42

Convection Currents in the Mantle cause tectonic plates to move. The mantle of the earth circulates much like water boiling in a pot. Where the mantle is rising, the plates are torn apart (divergent). Where the mantle is sinking, the plates are pulled together and subducted (convergent).

Answered by: Electronic engineer
24 October 2011 20:08

At time of writing (24/10/11), mankind has still to find an answer to that question. We understand how it operates, how it effects the earth & the rest of the known universe, but its cause remains unknown. Einstein believed that gravity was a property of space-time geometry & this year the Gravity Probe B satellite confirmed some of Einsteins key predictions mainly the warping of space & time http://www.bbc.co.uk/news/science-environment-13286241

Answered by: Environmental Scientist
20 October 2011 13:53

I assume you mean ‘pollution’ just in general rather than a particular type (noise, air, light etc). . .

If so, the European Environment Agency has some good, basics - http://www.eea.europa.eu/maps/ozone/whatcanIdo/avoid-ozone-pollution

Basically, if everyone did their “bit”, then it would have a positive global impact.

Answered by: Geology & Geophysics PhD student
24 October 2011 12:37

Hi Aakta! We now know that the Earth's outermost layer, the lithosphere, is divided into independently moving plates into which the continents are embedded. The plates "float" on a layer called the athenosphere. Here is a really good page from the BBC, with LOTS of resources, that tells you all about plate tectonics http://www.bbc.co.uk/science/earth/surface_and_interior/plate_tectonics I've copied a small paragraph which summarises plate tectonics really well and should give you a taster of the sort of info you can expect to find in the web page. There are some really good annimations and a great video by Dr. Iain Steward.

Answered by: Head of Education Services & Continued Learning, Royal Meteorological Society
29 September 2011 09:38

There is a very good answer with pictures on this website: http://www.sciencemadesimple.com/sky_blue.html

Answered by: Head of Science, St Pauls School, London
28 October 2011 14:34

Yes - the ground! If you see a rainbow from a plane, you can see a full circle. Look out for it - there are many wonderful optical effects other than rainbows, many of which can be seen from planes. Often you will see a rainbow in the clouds as you fly.

Answered by: Head of Education Services & Continued Learning, Royal Meteorological Society
01 November 2011 14:27

No, the ocean is blue because of the sky! The sky is blue because of the way the light we get from the sun interacts with the molecules in the air - there is a very good explanation with pictures on this website: http://www.sciencemadesimple.com/sky_blue.html

Answered by: Planetarium Presenter
19 October 2011 16:03

There are many different types of glass that have chemicals added to give it different properties, e.g. Ultra-violet (UV) reduction, Infra-red protection etc. Ordinary glass allows about 90% of light above a wavelength of around 350nm , but blocks about 90% below 300nm.

It is UV light (~200-400nm) that causes sunburn therefore the chances of becoming sunburnt are significantly reduced. However, infra-red light (heat) is well transmitted by glass, so your skin may redden as a result of the heat through glass.

Some types of glass have chemicals in them to reduce the UV light transmission further; often used in museums to reduce the effects of UV light on delicate artifacts.

Answered by: Geology & Geophysics PhD student
13 October 2011 10:46

Hi Daniel, The UK sits on the Eurasian Plate. In the centre of the Atlantic Ocean is the Mid-Atlantic ridge which is a divergent plate tectonic boundary that separates the Eurasian Plate from the North American Plate. Divergent means that it is pulling the two plates apart, at a rate of roughly 2.5cm a year. This means that the North American Plate is being pulled westwards, whilst the Eurasian Plate is being pulled eastwards. This means that the UK is being pulled towards Europe. However, all movement is relative, so that the rest of Europe is also moving eastwards, meaning that the distance between mainland Europe and the UK is not currently decreasing.

Answered by: Research Engineer, Lightning & Electrostatics
17 October 2011 10:19

I think you're a bit confused here - it's the other way round! The sea is blue because it reflects the colour of the sky! That's why the sea around the UK is normally a horrible grey colour...

Answered by: Head of Education Services & Continued Learning, Royal Meteorological Society
01 November 2011 14:28

There is a very good explanation about why the sky is blue with pictures on this website: http://www.sciencemadesimple.com/sky_blue.html

Answered by: Geology & Geophysics PhD student
05 October 2011 09:51

The oldest non-living object on Earth is a tiny speck of Zircon Crystal, that is so small, it is hardly visible with the naked eye and is thought to be 4.4billion years old. This is old if you think the Earth formed at about 4.57 billion years ago!!! The oldest rocks preserved on Earth are thought to be in Hudson Bay, Northwest Quebec, in Canada. A group of scientists dated them to be 4.28billion years old.

Answered by: Geologist & Hydrogeologist
04 October 2011 14:34

Lots and lots and lots! There are many many different soil classifications, depending on what you want to think about soil for. For example, you can classify soil based on the size of the grains in it (sand, silt, clay), or you can classify it on how strong it is (cohesive, weak etc). If you want to know whether it will be good to build on, you will need to know about its strength. If you want to know how well it will drain, you will need to know how sandy or clayey it is. If you want to go into huge depth, try googling soil taxonomy which is a classification with some lovely names like spodosols and hapluldalfs. Hapludalfs sound like gnomes to me!

Answered by: Geology & Geophysics PhD student
24 October 2011 13:09

Hi Zac!! That is a good question! I am afraid I don't know the exact answer, but I can say that there are is A LOT!!! Many many more than you can imagine!

Fossils vary in size from microscopic, such as single bacterial cells only one micrometer in diameter, to gigantic, such as dinosaurs and trees many metres long and weighing many tonnes. A fossil normally preserves only a portion of the deceased organism, usually that portion that was partially mineralized during life, such as the bones and teeth of vertebrates, or the chitinous or calcareous exoskeletons of invertebrates. Preservation of soft tissues is rare in the fossil record.

Fossils may also consist of the marks left behind by the organism while it was alive, such as the footprint or faeces (coprolites) of a reptile. These types of fossil are called trace fossils (or ichnofossils), as opposed to body fossils.

Answered by: Research Engineer, Lightning & Electrostatics
10 October 2011 10:34

Ice and water particles in the clouds constantly freeze, melt and move around bumping into each other. All of this causes a charge to build up which eventually gets too large and has to jump down to the ground - a bit like the charge building up in your body which escapes to the metal car or door handle and gives you a small electric shock. The path of the electricity from the cloud to the ground is the lightning strike.

Answered by: Environmental Scientist
20 October 2011 14:10

Corals are actually marine organisms – they are living things!

Answered by: Head of Science, St Pauls School, London
28 October 2011 14:33

Our tides result from the way the moon's gravity pulls on the Earth. The side of the Earth facing the moon is pulled most strongly and so the sea bulges there. The middle of the Earth is next most strongly pulled and so moves away from the sea on the far side, which is pulled more weakly. As the Earth rotates, the bulges stay facing the moon (which also orbits us but less quickly than we turn) and so appear to move round the earth. There is more to the story than that - the way water rises and falls by different amounts in different places, but it's a good start.

Moods...well no. We are too small to feel tidal effects, in spite of being largely water - the difference in the gravity on one side of us and the other is too small to notice. No proper studies have shown up an effect - those that have shown, say, more police trouble on full moons, have run over short periods where the full moons coincided with weekends when there is more trouble anyway. So there's no basis for the idea of lunacy being moon-driven, in spite of the name!

Answered by: Electronic engineer
04 November 2011 21:45

It depends on what mineral or ore they are hoping to mine for. In most cases these days it is possible to use 3 Dimensional Seismic surveys to show what lies below the ground. From this data the underlying geology can be analysed & matched to geology types that can contain coal, gold, silver or oil deposits. After geology that contains minable deposits is found it is common for test drilling to take place to sample & verify the minable deposits before full scale mining is carried out.

Answered by: Planetarium Presenter
21 November 2011 12:30

Stalactites hang from the roof of caves, whereas Stalactmites grow upwards from the ground.

Answered by: Geology & Geophysics PhD student
24 October 2011 12:59

Here is a good website that summarises a number of ways in which diamonds can form http://scrippsnews.ucsd.edu/Releases/?releaseID=736.

Read this blog post too which has some cool photos and images: http://geodynamo.wordpress.com/2010/05/23/kimberlites/. The first photo is that of a Kimberlite mine in South Africa, which I recently visited and it was really awesome! :)!

Answered by: Geology & Geophysics PhD student
24 October 2011 13:06

Plates move at quite a slow rate, so in 30 to 50 years time, we wouldn't expect the Earth to look significantly different to how it does now. For example, the mid-ocean ridge is moving at 2.5 centimetres per year (cm/yr), or 25 km in a million years. So in 50 years, the plates that are diverging from it, will only move by about 1metre.

Events like very large earthquakes, tsunamis and volcaninc eruptions are likely to cause localised changes in the way the Earth looks. Overall, on that time scale, the Earth will look very similar to how it does today.

Answered by: Environmental Scientist
20 October 2011 13:51

No-one, natively. The only people that "live" there are scientists and explorers. They use specialist equipment designed for extremely cold conditions.

Answered by: Geology & Geophysics PhD student
06 October 2011 21:36

The formation of natural diamond requires very specific conditions - exposure of carbon-bearing materials to high pressure, but relatively low temperature range between approximately 900–1300°C. These conditions are met in two places on Earth; deep down in the mantle below relatively stable continental plates (between 140km-190km deep), and at the site of a meteorite strike. The correct combination of temperature and pressure is only found in the thick, ancient, and stable parts of continental plates where regions known as cratons exist. Spending a long time in this environment allows diamond crystals to grow larger. Examples of cratons are the Slave craton in Canada, the Wyoming craton in the United States, the Amazonia craton in South America, and the Kaapvaal craton in South Africa.

Answered by: Electronic engineer
14 October 2011 14:30

At the sub atomic level there is something called a Quark of which there are 6 types. Each has a direction that may be either up, down, top, bottom, strange & charm quark. Quarks combine to forms of Hadrons of which a (Proton= 2 Up Quarks & 1 Down Quark) & (Neutron= 2 Down Quarks). The electron is not made up of Quarks & considered at this time (14/10/11) to be a fundamental particle so is not made up of any smaller sub units.

Answered by: Soil Scientist
14 November 2011 21:42

Many people had noticed the jigsaw-like fit between e.g. the Americas and Africa-Europe, since reasonably accurate maps first appeared. However, Alfred Wegener, a German scientist in the early 20th century, was the first to seriously propose that the continents moved around on the surface of the Earth. But he couldn't propose a mechanism - how did they move? It wasn't until the 1960s that later scientists discovered that ocean crust is continually being created at mid-ocean ridges and destroyed at subduction zones - and so continents are being pushed away from mid-ocean ridges (hence the Atlantic is getting wider). The rate and direction of movement can actually be measured today using very sensitive lasers and GPS, but we also have evidence of rates and directions in the past from measurements of palaeomagnetism on the seabed rocks. We can predict future movements based on current measurements.

Answered by: Professor of Earth Sciences
06 October 2011 12:55

The Earth is a little over 4.5 billion years old. We know this from the study of the radioactive decay of certain elements in meteorites, and from the study of the rocks exposed on the Earth's surface. The scientific concensus is that the Earth formed quickly from the collision and accumulation of meteorites, small planets and dust in a rapidly spinning and dense nebula; and that it formed soon after the formation of most meteorites (at about 4.56 billion years). The oldest rock fragments (in fact, crystals of zircon) on Earth, other than meteorites, are probably just a little bit older than about 4.4 billion years.

Answered by: Environmental Scientist
20 October 2011 14:19

For an awesome new resource by the British Geological Survey on the risk of future supply of minerals check this out - http://www.bgs.ac.uk/mineralsuk/statistics/riskList.html

Answered by: Geology & Geophysics PhD student
06 October 2011 21:52

http://www.youtube.com/watch?v=t9-lyZEgqlI This is a very interesting video - it is presented by Prof. Dan McKenzie, a distinguished geologist/geophysicist. In it, the discovery of how to measure the age of the Earth is explained! As a taster, I can tell you that we do it, using the decay of radioactive elements.

Answered by: Development Manager
06 June 2011 14:19

Bearing in mind the creation of the universe takes a while, then the creation of the earth would be quite some time. What would have happened is that assuming a fairly even distribution of matter, gradually some of the matter would start to coalesce - and as time marched on, more of it would be picked up - like a snowball turning into a part for a snowman. In addition, there were meteor strikes - some of which would just add to the mass, and others would knock some matter off the earth. Eventually, the earth would have been big enough to have its own atmosphere, and with the right conditions, start life. This would have taken many millions of years - starting from the big bang.

Answered by: Environmental Scientist
20 October 2011 14:42

In essence when it runs out of energy! This will depend on numerous factors.

Simplistically, volcanoes erupt because of a build up of pressure (other issues too!), but essentially when this pressure has been released, the eruption will cease. Pressure is from a build up of gases and therefore when this has been “degassed” this is when the eruption is likely to stop.

Answered by: Environmental Scientist
20 October 2011 15:04

Molten rock before its erupted is called magma. Once erupted this is called LAVA. Once cooled it forms igneous or magmatic rock.

Lava’s exact composition is dependant on geographic location and the concentration of gases.

Answered by: Environmental Scientist
28 October 2011 15:52

A Supervolcano is a large-scale eruption, GENERALLY defined by erupting material over 1,000km3. This is far greater than “normal” volcanoes. They tend to occur due to pressure build up in the magma chamber from hotspots or convergent boundaries.

Notable examples are Yellowstone (USA) and Campi Flegrei (Naples).

Answered by: Environmental Scientist
20 October 2011 15:08

Volcanic rocks are typically divided into four types. The categorisation is based on the amount of silica in the rock:

Basalt (48-52% silica), Andesite (52-63% silica), Dacite (63-68% slica), Rhyolite (68% silica).

Answered by: Environmental Scientist
20 October 2011 14:46

Useful website -

http://www.geo.mtu.edu/volcanoes/world.html

Answered by: Professor of Earth Sciences
06 October 2011 13:00

This completely depends on the volcano, and the eruption. At the one end, some eruptions are tiny, and last just a few hours as the molten rock escapes to the surface (there was an example of a very small eruption like this in Iceland in the 1970's). At the other end, some eruptions have been continuing for as long as humans have been recording observations (For example, the Stromboli volcano in Italy has been erupting on and off but continuously for at least 2000 years). Large explosive eruptions are usally over quite quickly - perhaps in just a few hours (like Mt St Helens in May 1980), or days (like Pinatubo, Philippines, in 1991); but quite often eruptions linger on for months or years, as they slowly wind down.

Answered by: Environmental Scientist
24 October 2011 10:55

The temperate range is 700° C to 1200° C. However this varies from volcano to volcano and from eruption to eruption.

Answered by: Environmental Scientist
28 October 2011 15:56

A lot of volcanoes occur after a period of seismic unrest and changes in the local environment that scientists read to gauge an impending eruption; hence why accuracy can be difficult!

For example:

- Harmonic tremors; these are common and are defined as a “sustained energy release” – they are like very small earthquakes almost continuously. They are not always felt by the local populace! - Soil and water can change pH. - Ground uplift or deflation. - Earthquakes. - Lava dome growth.

Answered by: Soil Scientist
28 May 2011 21:04

Hello. I guess you're asking specifically about the Grimsvotn eruption in Iceland? Well, its a good question to ask, since the eruption cloud of ash and gas did rise up to 20 km above the ground, which is well into the lower level of the stratosphere, where the ozone layer is found.

However, although there is some debate about the significance of volcanic impacts on the ozone layer the current general consensus is that these impacts are short-lived. The US Environmental Protection Agency has a good article on its website which debunks the 'myth', as it puts it, that volcanic activity has long-term impacts on ozone - http://www.epa.gov/Ozone/science/myths/volcano.html. The main agent of concern is hydrogen chloride (HCl) gas, which can very efficiently break down ozone. However, in most cases this gas will be removed from the eruption plume lower down, in the troposphere, where it condenses as rain or ice crystals and therefore does not react with the ozone.

On the other hand, volcanic plumes are full of very tiny dust particles, called aerosols, which can act as catalysts which increase the rate of reactions in the stratosphere. So the more aerosols are present in the ozone layer, the faster the ozone-depleting reactions. However, once again this harmful effect is limited by the gradual aggregation and settling of the particles out of the atmosphere.

So is there a risk of significant damage to the ozone layer from Grimsvotn? Probably not. Even though it is much larger than the Eyjafjallajökull eruption last year, Grimsvotn's current eruption is still 10 - 100 times less powerful than the Mt Pinatubo eruption in the Philippines in 1991, which is the only commonly-cited eruption to have made a significant measurable impact on the ozone layer. That effect, reducing lower-stratospheric ozone by up to one third, lasted for a few years only.

Useful websites: http://en.wikipedia.org/wiki/Gr%C3%ADmsv%C3%B6tn http://en.wikipedia.org/wiki/Volcanic_Explosivity_Index http://hvo.wr.usgs.gov/volcanowatch/2005/05_07_28.html http://volcano.oregonstate.edu/education/gases/ozone.html

Answered by: Head of Education Services & Continued Learning, Royal Meteorological Society
29 September 2011 10:03

A few extra points - according to the 2002 scientific assessment of ozone depletion, the 1991 eruption of Pinatubo only reduced the total amount of ozone by about 6%, for up to 4 years, and mostly affected the Northern Hemisphere. - when volcanic eruptions are powerful enough to get stuff up into the stratophere, they dont just effect the chemical processes going on. As they have an impact on the temperature of the stratosphere as well, there can be an effect on the dynamics of the stratosphere - how things are moved about.

Answered by: Environmental Scientist
20 October 2011 14:39

The British Geological Survey have a "Why no volcanoes?" download from their site.

Answers your question perfectly!

Answered by: Head of Education Services & Continued Learning, Royal Meteorological Society
19 October 2011 08:44

Heavy showers are often accompanied by downdraughts - strong currents of descending air that extend from the cloudbase to the ground. On hitting the ground these air currents then spread out and flow along the ground resulting in gusty winds that arrive just before the rain.

(answer supplied by Dr Pete Inness, from Reading University's Meteorology Department)

Answered by: Soil Scientist
01 November 2011 22:27

This seems like an odd question - I think there's strong evidence that weather reports are more accurate than ever. I wonder if perhaps our expectations of them have increased too much though - because they try to provide very precise, very specific forecasts we now expect them to be completely 100% perfect! I think that, aside from being able to say for certain the sun will rise tomorrow at a specified time in a specified place (which can be calculated precisely from the Earth's orbit and rotation), it is still amazing that anyone can forecast what the atmosphere is going to throw at us with any degree of certainty at all!

Answered by: Development Manager
21 June 2011 06:03

It may be because it makes them less vulnerable to lightning. It may be because rain may be preceded by a drop in atmospheric pressure, and this makes their stomachs feel more bloated. It may be because their joints are sensitive to a fall in atmospheric pressure like many people who have arthritis. However, there was a TV show that looked at this, and they filmed a field of cows before and during a rainstorm, and there was no correlation between cows lying down and the rain. So three more possibilities exist that I can quickly think of - one is that the phenomena doesn't exist; another is that cows only lie down with falling pressure; or that cows don't like being filmed lying down :-)

Answered by: Head of Education Services & Continued Learning/ Royal Meteorological Society
29 September 2011 09:07

From TheWeather Club magazine/website: If a well known piece of old countryside folklore is to be believed, a sure sign of the imminent arrival of rain is the sight of a herd of cows sitting down in a field. But then again, if old countryside folklore is to be believed, black dogs are devils and Londoners can't be trusted, so it's a claim that cries out for further examination.

In truth, it's fairly difficult to find a definitive answer as to whether or not the idea of a bovine weather gauge is pure bunkum, although it almost certainly is. So far, there's been no large-scale formal study of this phenomenon. The only ones who know for sure are the cows – and they're not telling.

At the heart of this myth lies the simple observation that cows often lie down shortly before it starts to rain. The problem with this, in evidential terms, is that both of these events – cows lying down, and the heavens opening – happen with such frequency that proving a link between the two is pretty much impossible. The fact that, in one of the dampest countries in the world, it quite often starts to rain shortly after some cows lie down is probably true - but it's also equally likely that a cow will lie down shortly before somebody talks about football or eats a sausage, yet nobody has ever suggested that cows are accurate predictors of sports-based conversations or bad diet. Cows often lie down before the sun comes out too, but nobody has ever pushed that as being significant. No country with less frequent rain seems to have made the same observation – if Indian cows all flopped down en masse with the coming of the monsoon, that would be impressive.

And if cows do lie down before it rains, what on earth is their motive? It has been suggested that cows don't like sitting in wet grass, or dislike eating wet grass and so are keeping a patch dry, or that cows slip over when it gets wet so are taking precautionary measures. Can cows really be so precious? The only thing we know for sure is that they do tend to lie down when chewing the cud – something that has absolutely no bearing on the weather.

The last word should go to meteorologist Bill Giles: "I used to ask a farmer friend, who swore by the saying, what happened if half were standing, and half were lying down. He turned to me and said one word: 'Showery'!"

Answered by: Head of Education Services & Continued Learning, Royal Meteorological Society
18 October 2011 09:48

You get clouds when water vapour condenses into lots of tiny water droplets. For this to happen, there firstly has to be a reasonable amount of water vapour in the atmosphere - for example if the air has recently travelled over an ocean (usually the case for the UK). Then, the air has to be cooled down - maybe by coming into contact with colder ground (UK in winter) or because of convection - as air rises, it expands and cools. Whilst there will be lots of convection going on in Egypt, as the air is heated from underneath by the warm ground, if there isnt enough moisture in the air, clouds won't form. In Northern Hemisphere winter, Egypt might also experience relatively high pressure, with subsiding air, which we associate with clear skies. Satellite images are great for seeing where cloud is forming.

Answered by: Soil Scientist
01 November 2011 22:13

Hello. Snowflakes are formed of ice crystals which grow (nucleate) around tiny particles of dust suspended in the air. It is the same process by which a raindrop forms from water vapour, except of course the temperature must be sufficiently low so that ice, rather than liquid water, is condensed.

The key thing to remember is that it is the individual molecules of water that are hooking up to each other, one by one, to form the ice crystal. Although there are only a few ways in which each molecule can join to another one (a bit like fitting hexagonal tiles together), there is no limit as to where on the crystal each one joins, no rule which says every space must be filled in a certain order, and no constraint on the time each snowflake has to grow, or the changes in temperature it experiences, or so on. Essentially the growth, although constructed around the hexagonal geometry of the water molecule, is completely random - all combinations of molecules are possible.

Now, each snowflake has about 10 billion billion (1 with 19 zeros after it!) molecules, and the total number of different combinations all those molecules can form is so large it might as well be infinite. On the other hand, David Phillips, the senior climatologist with Environment Canada, has estimated that the number of snowflakes that have fallen on Earth over the course of time is 10 followed by 34 zeros! While that's a lot, its still a lot less than infinity - so the chances of any two snowflakes ever being alike are therefore more or less zero. In all probability, then, all snowflakes are different and its because of the random, or 'stochastic' way in which they form. I should credit a Feb 13, 2007 National Geographic article by John Roach for some of the figures I quote.

Answered by: Research Engineer, Lightning & Electrostatics
10 October 2011 10:34

Ice and water particles in the clouds constantly freeze, melt and move around bumping into each other. All of this causes a charge to build up which eventually gets too large and has to jump down to the ground - a bit like the charge building up in your body which escapes to the metal car or door handle and gives you a small electric shock. The path of the electricity from the cloud to the ground is the lightning strike.

Answered by: Head of Education Services & Continued Learning, Royal Meteorological Society
18 October 2011 09:53

They don't, necessarily! If there is low cloud (fog or sheets of low lying stratus) which has formed overnight if the air has been cooled by the ground, then the Sun can 'burn' (evaporate) this cloud away in the morning. However, more typically, we associate sunny, warm days with convection - the Sun heats up the ground, the ground heats up the air above it and it starts to rise. As it rises, it expands and cools until eventually the rate at which water vapour is condensing is faster than the rate at which water is evaporating - and cloud's droplets form. Then we get the puffy cumulus clouds which we associate with warm days. These can grow into the huge cumulonimbus clouds which bring us thunderstorms and sometimes tornadoes.

Answered by: Head of Education Services & Continued Learning, Royal Meteorological Society
03 November 2011 16:14

Vostok station in Antarctica reached -89.2C on 21/7/1983. In the middle of the Antarctic winter, a very tight vortex develops around the South Pole, mainly because the continent is pretty symmetrical. This isolates it from the air further North, meaning no warmer air is mixed in. In the Polar night, the air just keeps getting colder until the sun returns in the spring. This is also the reason why stratospheric ozone loss is most severe over the south pole.

Answered by: Head of Education Services & Continued Learning, Royal Meteorological Society
18 October 2011 10:08

We get wind when there is a pressure difference in the atmosphere - air flows from high pressure to low pressure. It's easier to think of if you think of two containers of water, with a barrier inbetween them. If one container has deep water (high pressure) and one has shallow water (low pressure) and you suddenly remove the barrier between them, then you would expect the water to flow until the water level was the same in both containers. Same thing goes on in the atmosphere, complicated by friction at the Earth's surface, and the fact that the Earth is rotating. But basically, the bigger the pressure difference, the faster the wind speeds - so when a really deep low pressure system is heading our way, we know that it's going to be windy.

Answered by: Head of Education Services & Continued Learning, Royal Meteorological Society
01 November 2011 14:37

For us in the UK, a small island with a big ocean on one side and a big continent on the other, it all depends on where the wind is blowing from, and what time of year it is. Depending on whether the air has passed over a warm, cold, wet or dry surface before reaching us will effect what weather we get.

Answered by: Chief Executive, Royal Meteorological Society
02 November 2011 11:14

In order for a thunder cloud (known as a cumulonimbus cloud) to form, the air has to be unstable. This means the air is warm near the ground but cooler higher up. For example, warm air is found near the ground on a sunny day, when the sun heats the ground and the ground heats the air in contact with it. If at the same time the air higher up is cool (perhaps because it has been blown in from the north), then the warm air near the ground will rise up because it is less dense than the cool air above. This process is called convection. If the temperature of the warm air is much greater than that of the cold air above, then this convection will be intense and cause strong updrafts, or thermals. This typically happens in mid-afternoon, when the ground has been warmed for several hours.

As the warm air rises, it expands and cools, until it is too cold to 'hold' all of the water vapour it has in it (we call this temperature the "dew point") and so some of the water vapour condenses into water droplets, thus forming a cloud. The top of the cloud is carried higher and higher by the strong thermals, and can eventually reach 10km or more. The temperature there is so low that some of the water turns to ice crystals - hence the top of a thunderstorm cloud is usually fuzzy in appearance.

The ice crystals are different sizes, and when they collide within the cloud they build up an electric charge. Because of rising and sinking air within the cloud, this charge can separate to give a large positive charge at the top of the cloud and a large negative charge at the bottom. When the charges build up enough, they are discharged in a bolt of lightning inside the cloud. When the thunder cloud passes over the ground it induces an opposite charge at the ground, and then lightning can jump from the bottom of the cloud to the ground. Lightning strokes heat up the air very rapidly and make it expand explosively - this is what we hear as thunder.

Answered by: Research Engineer, Lightning & Electrostatics
24 October 2011 14:49

Charge builds up in the clouds and eventually that charge needs to escape. It discharges down to the earth and the path of electricity is the lightening strike. The heat from this is hotter than the surface of the sun and makes the air expand really quickly - this creates a shock wave producing the sound we know as a thunder clap.

Answered by: Environmental Scientist
20 October 2011 15:21

Compared to some other natural phenomena, weather science, to some extent, can be monitored and predicted.

The Met Office is responsible for the UK’s severe weather warnings and although lead time on some events can still be too short there is a good, established process in place.

http://www.metoffice.gov.uk/weather/uk/advice/

Answered by: Head of Education Services & Continued Learning, Royal Meteorological Society
18 October 2011 09:31

There are 10 main types of cloud: cirrocumulus, cirrus, cirrostatus, altocumulus, altostratus, cumulus, stratocumulus, stratus, cumulonimbus and nimbostratus. However, there are variations of some of those - for example Cumulus Humilis, or stratocumulus lenticularis.

There is lots more information in Gavin Pretor Pinneys 'Cloudspotters Guide' or on the RMetS website http://www.metlink.org/weather-climate-resources-teachers/useful-links.html#clouds

Answered by: Head of Education Services & Continued Learning, Royal Meteorological Society
18 October 2011 10:09

We get wind when there is a pressure difference in the atmosphere - air flows from high pressure to low pressure. It's easier to think of if you think of two containers of water, with a barrier inbetween them. If one container has deep water (high pressure) and one has shallow water (low pressure) and you suddenly remove the barrier between them, then you would expect the water to flow until the water level was the same in both containers. Same thing goes on in the atmosphere, complicated by friction at the Earth's surface, and the fact that the Earth is rotating. But basically, the bigger the pressure difference, the faster the wind speeds - so when a really deep low pressure system is heading our way, we know that it's going to be windy

Answered by: Soil Scientist
01 November 2011 21:52

Hello Pete. All rainwater is slightly acid (pH 6 ish), because the water droplets react with carbon dioxide in the atmosphere to form carbonic acid (H2CO3). However, increased levels of sulphur and nitrogen gases in the atmosphere cause more powerful acids to form - sulphuric acid and nitric acid - which can lower the pH of the rainwater to as low as 2.

Although there are substantial variations in the levels of these gases depending on where you are in the world and what direction the wind is blowing, in the latter part of the last century it became clear that heavy industries were responsible for highly acidic rainwater across large areas of Europe and the US.

Answered by: Environmental Scientist
20 October 2011 15:18

Hopefully this will answer some of your questions - http://www.metoffice.gov.uk/research/weather

Answered by: Research Engineer, Lightning & Electrostatics
31 October 2011 12:01

Charge builds up in the clouds and eventually that charge needs to escape. It discharges down to the earth and the path of electricity is the lightning strike. The heat from this is hotter than the surface of the sun and makes the air expand really quickly - this creates a shock wave producing the sound we know as a thunder clap.

Answered by: Head of Education Services & Continued Learning, Royal Meteorological Society
01 November 2011 14:34

Meteorologists need three things to be able to predict the weather:

1. Really good data describing what the weather is doing now. This comes from weather stations, satellites, radar, weather buoys, etc.

2. A good understanding of how the atmosphere (and oceans) work - and to be able to describe that in terms of equations.

3. A really powerful computer, to let you solve all the equations before the weather you are trying to predict actually happens.

Answered by: Chief Executive, Royal Meteorological Society
02 November 2011 11:21

To forecast weather over the next few days, meteorologists develop and use very large computer programmes known as numerical weather prediction models. These represent the processes that take place in the atmosphere such as the movement of air (both horizontally and vertically), the transfer of heat and water vapour, the generation of clouds and rainfall, how sunlight and infra-red radiation pass through the atmosphere, and many, many more.

The model is started with the current state of the atmosphere, represented on a three-dimensional grid of points covering the whole globe and stretching from the surface to the stratosphere. A set of atmospheric variables, such as wind speed, temperature, pressure and humidity at each grid point are stored and a set of equations are solved to predict the values at that point a short time later. This process is repeated many times; each time the forecast stepping a few minutes further into the future to stimulate the evolution of the weather over the next few days.

The model requires huge numbers of observations to tell it what the starting state of the atmosphere is. These come from weather stations, weather balloons, ships, buoys, aircraft and weather satellites.

The chief forecaster (such as the one at the Met Office in Exeter) depends heavily on forecasts from several models to help him decide on how the weather will change, and also takes into account predictions from models run by other countries such as the US and Germany.

Answered by: Environmental Scientist
20 October 2011 15:37

Rain clouds, or Nimbostratus, are characterised by being grey and formless.

Answered by: Head of Education Services & Continued Learning, Royal Meteorological Society
01 November 2011 14:16

"Cumulus are low, detached, puffy clouds that develop vertically in rising mounds, domes or towers, and have generally flat bases. Their upper parts often resemble cauliflowers and they appear brilliant white when reflecting high sunlight, but can look dark when the sun is behind them. Cumulus tend to be randomly scattered across the sky." (Taken from Gavin Pretor-Pinneys Cloudspotters Guide)

Answered by: Postdoctoral researcher in Electrical engineering
13 May 2011 11:52

Hi Char, Lightning is the sudden movement of 'charged' particles from the sky to the ground. The principle behind lightning is static electricity you might be more familiar with this if your hair ever stands on end when putting on a jumper, or sometimes you can get a mini electric shock from a car door. Static electricity is caused by particles becoming charged, typically this means atoms gaining or losing electrons as they rub against each other. This leads to areas of positive and negative charges, once the charge is big enough the electrons move from the negative to the positive region restoring neutral atoms and this is the flow of static electricity. The origin of charged particles in the sky responsible for lighting is still unclear although it seems most likely to be caused by small ice particles hitting each other and becoming charged. This charge build up then becomes so great that the electrons can jump all the way to the earth.

Answered by: Research Engineer, Lightning & Electrostatics
01 August 2011 09:24

As ice and water particles rub against each other in the cloud, the frictional force causes them to become charged - positively charged particles rise to the top of the cloud and negative ones sink to the base. Because similar charges repel (just like two north poles on a magnet repel each other), the negative charges at the base of the cloud force the negative charges on the earth lower down and so the earth's surface becomes positive. Nature always wants to balance it back out so eventually, a path of electricity travels between the regions of positive and negative charge - that's the lightning strike!

Answered by: Head of Education Services & Continued Learning, Royal Meteorological Society
18 October 2011 09:58

If you look at a cloud, you'll see that it usually has a pretty flat base. This is because the temperature of the atmosphere falls as you go up, and the cloud forms when the temperature is below a certain value. The actual air inside the cloud is continually moving, and the water droplets which we can see are also moving, growing, and shrinking all the time, but we see a cloud where the conditions (temperature, humidity) are just right for a cloud to exist. Once the water droplets that make up the cloud get big enough, and the gravitational pull of the Earth is bigger than the combined effects of the updraughts in the cloud, friction etc. then the droplets fall down - and if they dont evaporate again on their way down, then we get rain.

Answered by: Head of Education Services & Continued Learning, Royal Meteorological Society
18 October 2011 09:35

Clouds are created when water condenses in the atmosphere - in the same way as you get condensation on bathroom mirrors and windows when someone is having a bath. Cloud droplets can exist when there is more condensation going on than evaporation, which usually means when the temperature of the air is cold enough.

As air temperature generally falls with height, this means that clouds can form above a certain level. It's complicated a bit by the fact that clouds can't form in clean air, the water needs something to condense onto - salt sprayed up from the oceans, soot, sulphate particles etc.

There is lots more information on http://www.metlink.org/weather-climate-resources-teachers/useful-links.html#clouds

Answered by: Soil Scientist
01 November 2011 22:22

I'm not sure how much research has been done into this (perhaps Wikipedia could help here?), but quite apart from the fact that cold rainy weather is not particularly comfortable and warm sunny weather is, I think there are two key effects:

(i) Pressure differences - Most of our weather is associated with changes in atmospheric pressure (you will have heard of high pressure associated with calm, sunny weather and low pressure associated with wind and rain storms). These pressure changes are literally differences in the weight of air pressing down on our bodies. Ordinarily we don't think about this because we are adapted to the weight, but it is significant and its possible that people are physically affected by variations.

(ii) Seasonal Affective Disorder is a condition in which the low light levels, cold, and darkness of winter cause often serious mental depression in sufferers. It has been linked with a low production of Vitamin D and seratonin (a 'happiness hormone') because of a lack of sunlight. In places like Scandinavia, which have long dark winters, special sunbed-style lightboxes are widely available to the public to try and prevent these depressive episodes. Similar daylight-simulating lamps are also on sale here in the UK. So I think there are certainly some good physical bases for proposing a link between weather, seasons and our well-being (although I repeat that I don't know what scientific evidence there is).

Answered by: Head of Education Services & Continued Learning, Royal Meteorological Society
01 November 2011 14:32

Yes, as the climate changes, so do the timings of the seasons. The most obvious change is that spring is coming earlier - at least in terms of when plants and animals start doing spring-like things. Of course, the orbit of the Earth around the Sun hasn't changed, so if you define the start of spring as the day when the Sun is overhead at the Equator (21st March ish) then that hasn't changed. The study of 'when things happen', at least in terms of the effects of the seasons on plants and animals, is called phenology.

Answered by: Professor of Materials Physics
12 May 2011 11:25

Hi, the wool we wear has been heavily treated so it's not really the same as when it's on the sheep's back. For one thing, the wool fibres on a sheep are coated with a natural oil, lanolin, which effectively makes them waterproof. Best wishes, Bob - Professor of Materials Physics.

Answered by: Outreach Officer, Department of Engineering
21 September 2011 17:24

Metal zips and chunky plastic zips have a bulge on one side of each tooth and an indent on the other. The teeth are offset on each side of the zipper tape and the bulges and dents have a carefully curved profile. When you drag the Y-shaped slider over the teeth, it squashes the teeth together so each dent slides over the bulge on the tooth opposite and below it and locks into place. Dragging the slider back down reverses the process and forces the teeth apart. Lightweight plastic zips use a coil of stiff nylon to make the bulges and dents.

Answered by: Development Manager
12 September 2011 15:18

A fabric can be made to be water and dirt repellent by making the pores smaller to prevent water molecules passing through - or by using a barrier that relies on osmosis (where molecules with sweat will pass through a membrane to the side with a lower concentration of sweat).

To stop the dirt adhering, you need a fabric with a very smooth coating - so one way this can be done is with a teflon coating - as used in frying pans - and this coating is very smooth, so dirt or your cooking finds it more difficult to stick to the surface - and makes it easier to remove the dirt - or cooking. Just don't confuse your frying pan with your clothes, as it will either ruin your food, or be very uncomfortable to wear!

Answered by: Outreach Officer, Department of Engineering
21 September 2011 17:31

No! It's gone up faster because we are plumper than our ancestors. However manufacturers use a tactic called "vanity sizing" - what was a size 12 in the 1970s is a 10 or an 8 now. We all feel good about fitting into a smaller size and more inclined to buy clothes with lower numbers. Sewing patterns stopped vanity sizing in the 1970s, which is why your pattern size is different to your high street size. Use a tape measure on yourself before buying a sewing pattern!

Answered by: Medical student
04 September 2011 22:52

No - providing you're not wearing them so tight that it cuts the blood off to your feet! Having said that, wearing too low rise jeans that are too tight around the hips causes a condition called meralgia paraesthetica (also known as entrapment of the lateral cutaneous nerve of the thigh). The nerve that supplies the outside part of your thigh becomes irritated as it gets pushed on between the tight jeans and the bones of your hip and sufferers tend to get pins and needles and pain down the outside of their thigh. The cure - stop wearing tight jeans!

Answered by: Outreach Officer, Department of Engineering
21 September 2011 17:12

Yes - if they are made with real metal, not just lightweight shiny plastic. Cloth of gold is made from the best conductor there is. Most fashion "metallic" fabrics are the plastic sort though because it is cheap and lightweight clothing is nicer to wear.

Answered by: Chartered Building Services Engineer
27 July 2011 10:17

In order to digest Lactose (which is a sugar found in milk & other dairy products) you need the enzyme Lactase. When you are very little, you produce lots of lactase so you can breast feed or drink other milk. As you get older and are weaned you start to produce less lactase. For some people the amount of lactase they produce drops so low that they are no longer able to digest lactose (and therefore dairy products) at all! This can also be triggered by certain illnesses that affect the digestive system.

Answered by: PhD research scholar in Microelectronics & Nanostructures
02 June 2011 09:59

Like all food allergies, banana allergy is also caused due to a protein known as chitinase. Chitinase often causes the immune system of the body to react in an unfavorable manner. This is a type 1 allergy caused by contact with bananas. People who have a banana allergy may also be allergic to kiwi fruit and avocado because the protein chitinase is also present in these other fruits.

Banana allergy is not a very common disorder. A lot of people who claim to be allergic to bananas in fact only have intolerance towards the fruit. There are certain amines in bananas which cannot be digested by those who have a weak and sensitive digestive system. The enzyme called diamine oxidase, which is used to digest these amines may be absent in certain individuals. Such people are not able to breakdown the proteins in bananas and therefore have allergy type reactions which are often mistaken for the actual banana allergy.

Answered by: PhD Student
12 July 2011 18:33

Allergies are caused by your immune cells becoming hyperactive when they encounter something that you are allergic to, say a peanut. Your immune system recognises this normally harmless substance as a pathogen and tries to attack it. This can can inflammation, which you might see as a rash on your skin or, in rare cases, can cause your airways to narrow.

Answered by: Development Manager
27 June 2011 11:32

Most people are allergic to some allergens - but some reactions are so common, they are not considered allergic reactions - such as those to nettle stings or bee and wasp stings. As for food reactions, once again, it is a protein in the food that the body considers to be harmful, and so tries to protect the body from the allergen by releasing a chemical call histamine. Histamine performs a variety of functions, but one of them allows more white blood cells to attack the pathogen. In extreme cases, a person will need a kick start as their body over-reacts to a pathogen - this is known as anaphalaxis, and is often associated with nut allergies. The allergic response has a strong hereditary link, although environmental factors can play a part, with the influence being more effective in younger people.

Answered by: Consultant, Food Safety, IFST
05 July 2011 08:05

It may not be weird, but most people that are allergic to kiwi are actually triggered by the hairs on the kiwi and mostly they also have an allergy to latex too.

Answered by: Medical student
21 June 2011 01:04

To the best of my knowledge, there is no strong evidence that any changes in diet affect the way a person suffers from hayfever, which is an allergy to pollen. Having said this, some people also develop associated food allergies. For example, people who are allergic to silver birch pollen have tended to develop oral allergies to things like apples, peaches, cherries, carrots, celery, hazelnuts, peanuts or walnuts. Similarly, people who are allergic to grass pollen have tended to develop oral allergies to tomato, melon or watermelon. They experience the allergy as a tingling or itching within their mouths when they eat the food raw; it very very rarely develops into any more serious like anaphylaxis.

Answered by: PhD research scholar in Microelectronics & Nanostructures
03 June 2011 18:35

Lactose intolerance is the inability to metabolize lactose, because of a lack of the required enzyme lactase in the digestive system. Disaccharides cannot be absorbed through the wall of the small intestine into the bloodstream, so in the absence of lactase, lactose present in ingested dairy products passes intact into the colon. The enteric bacteria then quickly switches its operation to lactose metabolism, and the resulting fermentation produces copious amounts of gas (a mixture of hydrogen, carbon dioxide, and methane). This, in turn, may cause a range of abdominal symptoms, including stomach cramps, nausea, bloating, acid reflux and flatulence.

Lactic acid bacteria in the intestines breaks lactose down into short-chain fatty acids and other substances that can be absorbed by the colon.Acidophilus is one of many types of lactic acid bacteria. Lactic acid bacteria are available as dietary supplements.Yogurt containing live active bacteria is believed to improve lactose digestion for the same reason that probiotics are thought to work.

Answered by: Development Manager
10 September 2011 10:25

A balanced diet has the right proportions of minerals, vitamins, protein, carbohydrates etc., so that our bodies are able to digest and extract those elements it needs efficiently, and yet not adding to surpluses that we don't want - which may be detrimental if eaten in too high a quantity - such as salt and fat!

Answered by: Postdoctoral Researcher in Microbiology & Structural Biology
14 May 2011 12:25

Vitamins and minerals are needed by our bodies as our cells cannot produce them, but need them to be able to work. We get most of our vitamins and minerals from the food we eat, but a few vitamins are made by the bacteria which live in the large intestine.

We need iron to make the haemoglobin which gives red blood cells their colour and allows them to transport oxygen. Calcium is needed to make teeth and bones and most cells use it to function properly.

The vitamins we eat are used by our cells. The B vitamins that breakfast cereals are fortified with allow our bodies to use the energy from sugars and to make the molecules that cells need to function. Diseases, like scurvy and rickets are caused by a lack of vitamins, so it is very important to ensure your diet contains enough vitamins.

Answered by: Development Manager
10 September 2011 10:51

Most foods can be "best" - according to what our body needs at that time! A balanced diet contains lots of "best foods" contributing to satisfying what our bodies need. Once we start eating too much of a "best" food, then it may become a "poor" food - so if we eat the right amount of salt - that is healthy - too much and it can cause high blood pressure. Similarly we need iron to replenish our red blood cells, but too much can be unhealthy!

Answered by: PhD Student in bioactive glass research
10 June 2011 23:18

Essenially a diet with no meat of fish would still need to be a balanced diet so you would still need to eat food from each of the food groups, carbohydrates (breads and pasta type foods) you would still need fats and fibre and vitamins and mineral ( some people feel that if your not eating meat you will need to take vitamin and mineral suplements to make sure you stay healthy) and finally you still need to eat protein which is normally eaten as meat, eggs and cheeses although there are some proteins that are not meat.

Answered by: Mechanical engineering student
08 December 2011 14:34

Benefits include improved heart health (high in unsaturated fats) and lowered low-density lipoprotein (the "bad" cholesterol). Nuts are also high in fibre and can therefore fill you up more quickly. However, if they are covered in sugar, chocolate or salt that can cancel out the health benefits. Your blood pressure can actually be raised if the nuts are fried in oil and salted! They are also high in calories due to their high fat content - consuming a small handful (1oz, roughly 28.4g) of nuts will set you back 160-200kcal on average. You will need to substitute nuts with something else in your diet (e.g. instead of cookies) if you don't want to gain weight.

There is no specific selection of nuts recommended for a vegetarian because all varieties contain the amino acids and healthy fats you need. You could try walnuts, which have high levels of omega-3 fatty acids. Almonds, peanuts, brazil nuts, pumpkin/sunflower seeds all seem to be good choices too. As little as 1oz a day will give you all the nutrients you need!

Answered by: Project Coordinator for Dublin City of Science 2012
11 August 2011 15:01

Firstly, some general advice is here:

http://en.wikipedia.org/wiki/Healthy_diet

Secondly... usually vegetarians require some extra protein and are unable to intake sufficient complete proteins (usually gotten from animal flesh). You can take protein supplements which usually taste kinda nasty or cook more beans with rice and other things that combine to make complete proteins. The more varied fruits and veg and nuts and seeds you consume the more likely you are to have a complete diet.

Answered by: Development Manager
10 September 2011 10:29

Different species may have a different diet for a number of reasons - firstly maybe the environment precludes them eating some foods; maybe they have evolved to eat certain foods so that there isn't too much competition for any foodstuffs. Some creatures may need more energy from their foods than others - but I suspect most animals will require to eat so they obtain similar nutrients so they can have energy, and can replenish the minerals and vitamins needed. I think it will be more a case of the proportions may differ between species, and how they obtain them will differ!

Answered by: Development Manager
15 June 2011 06:56

It is difficult to answer specifically without knowing your lifestyle and current diet - but instead of snacking on maybe a packet of crisps maybe consider eating an apple or some nuts; for breakfast maybe think about swapping sugar for berries or banana on your cereals (I doubt they would go with bacon and eggs!); and maybe think about some home cooking for dinner - whereby you cook in batches and freeze - which can still make a pasta dish or a stir fry quite efficient; and for lunch think of replacing a sandwich with a salad - then it can be quite easy to exceed your five a day!