Fast and furious geology
I visited the Festival of Science and Arts at London’s Southbank last Friday. Part of the event is the Royal Society’s annual summer science exhibition, which gives visitors the opportunity to meet some of the scientists who are leading the country in cutting-edge research. It is well worth a visit, and you have until this Sunday to take a look yourself.
Many of the projects caught my eye, including a group of geologists who are studying the birth of Africa’s newest ocean which is happening right now in front of their eyes, not the usual extremely slow geological processes that take millions of years for the tiniest change to be noticeable.
The team are studying the Afar region in Ethiopia. This region lies on a divergent plate boundary and back in 2005 a 60-km long segment of the boundary cracked open by 8 metres. This was filled with 2.5 cubic km of magma – enough to fill the centre of London up to 60m (half the height of the London eye). The fact that this happened on the surface of the Earth (divergent plate boundaries usually happen under the oceans like the one in the middle of the Atlantic) and because the changes are happening so quickly, it gives geologists an amazing insight into plate tectonics.
If this movement continues, in 20 million years (a short time in geological events) a portion of East Africa will have completely separated from the mainland as a new sea is born – as seen in the image on the right.
This is a great way of putting plate tectonics into a context, and showing students the kinds of techniques that are used in studying the rift. Space geodesists use satellites to make precise measurements of how much the crust has moved, and because this area of Africa is very arid the lack of plant cover makes it easy to take these measurements. Seismologists study the seismic waves that occur when the rift opens, and volcanologists are studying the magma chambers that exist below the crust in this area. They can use this data to predict volcanic eruptions – the latest being in May of this year, therefore this study does not just inform the scientific community of how plate tectonics shape our world, but the data can help reduce the risks to the people who live in this region.
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