Stoke Earthquake…

Today an earthquake hit the Newchapel area of Stoke on Trent.

Magnitude 2.4 is not massive on the scale of earthquakes – but it is one of the more noticeable ones for this area.

Most of the earthquakes in North Staffordshire are to do with old coal mines shifting and settling. But this one is to do with the plates of rock in the Earth’s surface shifting. Although the UK is away from the edges the large continental plates (so no large earthquakes) – there are still big pieces of rock moving around. This is why we have mountains and hills in certain parts of the country while others are fairly flat.

The south end of Stoke on Trent (Barlaston on this map) is right at the point where two plates are moving – above that are the hills of the Staffordshire Moors and the Derbyshire Dales. To the west – the Malvern Hills and the Welsh mountains. To the east are “concealed” mountains – the mountains possibly buried by sedimentation when this was sea bed.

The sudden movement of the rocks will release lots of energy (earthquake) that has built up over time. As the sliding rocks get “jammed” and their movement stops, stored energy builds up.

In the UK movement of faults between plates of rock are generally slow, but over years the effects can be seen.

Mr G

Sources: BBC News,  Quarterly Journal of Engineering (images)

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Updated – Chile Volcano Pics

This BBC webpage has a slide show of pictures from the recent eruptions in Chile.

Update – PopSci also has a gallery of photos.

This ties in well with the Y8 topic on Geology. For more volcano photos you can look back at these old blog posts here, here and here.

Mr G

Sources: BBC News Website

Japan… article updated.

Earthquake and tsunami

Unless you’ve been hiding under your pillow for the last few days you must have heard of the magnitude 8.9 9 Earthquake that happened under the ocean near Japan, causing a massive Tsunami that flooded much of the coast.

Here you can see footage of the

And here you can see pictures of the damage by sliding the bar to see the before and after pictures.

You can see from this diagram why the tsunami killed so many people – the earthquake was so close to the shore there was only minutes to warn and evaquate people.

The earthquake even reached the UK, my old university (Keele) recorded the earthquake using their seismometers, it was so big it still went off the scale half the world away.

The full details of the earthquake can be found here on the usgs.com website

The first episode of the new series of BBC’s Bang Goes the Theory was dedicated to the science behind the Japan earthquake and tsunami. You can watch it on iPlayer here.

Here is a clip from the episode showing how earthquake build up so much energy and how tsunami are formed when the seabed shifts suddenly.

Japan has a good record of designing buildings that can survive earthquakes, as can been seen in the video. Wooden buildings are generally good because they can flex without breaking. But a tsunami is a different proposition – with a large mass of water flowing through them few buildings can survive.

Nuclear Reactor

During the earthquake Japans nuclear reactors were shut down. Control rods moved in to stop the reactions, but nuclear reactors get very hot and it takes days and weeks to cool them down. Unfortunately it is the cooling of the reactors that has been the problem. Water pumps have been damaged, so the coolant inside the reactors has been boiling, needing releases of pressure that have taken small amounts of radioactive material with them. Some of these pressure releases exploded – the coolant water having split into hydrogen and oxygen. If the coolant falls below the level of the fuel rods, the fuel rods can over heat and start to melt – this is called a melt down.

As long as the main case of the reactor is not damaged then the bulk of the radioactive material remains safe. Only tiny amounts have been released with the steam (still en0ugh to be over legal limits, but nothing like the dangerous levels seen after Chernobyl exploded). Keep updated

Updates…

  • This Telegraph article gives numbers that highlight the scale of the earthquakes effects
  • This BBC page shows the stages the nuclear power plant has gone through and answers some questions about the radioactivity – including discussing the risks and comparing it to Chernobyl
  • The video below illustrates what has been going on with the reactor

Mr G

Sources: BBC News, ABC News, MSNBC, BBC iPlayer, Hypocentral.com,  usgs.gov, Telegraph

Global Warming – The Ice is Melting…

Some people still argue over if humans are responsible for Global Warming – but most of those admit it is happening!!

The Independent recently printed an article “Arctic sea ice shrinks to third lowest area on record” – where the 3 years with the least ice are in the last 4 year!!

This page on The Cryosphere Today site has images of the ice going back years (you can pick your own dates to compare). You can see the ice grow as winter comes and melt as summer approaches.

This image shows the difference between this month and 10 years ago! Just the a year ago ships passed over the top of the earth – taking a massive short cut from the atlantic to the pacific!

Sea ice like this will not cause the oceans to rise – it’s already in the ocean. But ice is also on land so when that melts the ocean gets bigger and deeper causing flooding to low areas of the world.

Mr G

Giant Hole in Guatemala

A 330ft deep and 60 metres diameter hole, opened up in Guatemala earlier this June and what is so weird is that it is perfectly circular. It has not been reported that anyone has been killed but a lorry and up to twenty houses were swallowed by it.

This phenomenon is common in places that have limestone bedrock interspersed with caves, and is common in all continents except Antarctica. This bedrock that contains carbonates, such as limestone, are prone to chemical weathering, so these holes can be caused when the underground caves can no longer support the sediment above them, and so they collapse, and can also be triggered by a tiny amount of rain.

When i saw this i was astonished but it reminded me of Fantastic four: Rise of the Silver Surfer 🙂

Alienferret

What do they mean by a “Top Kill”?

[Images taken from the BBC website]

The oil well that’s been leakig for well over a month now, polluting the seas around Florida and the Gulf of Mexico.

Top kill is basically squirting stuff into the hole and hope it gets bunged up.

Starting with a heavy, clay based mud pumped into the well head’s “blow out preventer”, a set of valves that should have sealed the leak, the flow should be stopped. If that isn’t totally successful they can also add “junk” to the mud, like golf balls which will jam up the pipe and give the mud something to cling to.

These BBC articles have more information;

BP have live footage of the leak from with Remote Vehicles.

Mr G

More Beautiful Science…

Today must be a day for stunning Science pictures… Now we get to Astrophysics and Geophysics creating a simmering and shimmering vista.

See this Daily Mail article for more pictures…

Mr G