What makes earthquakes? Although there are many causes, including volcanoes, the most common thing that causes them are tectonic motions, which also cause tsunamis. But as valuable as it is to understand other planets in our solar system and in other star systems, sometimes it’s important to understand what’s going on inside our own planet.
The crust of the Earth actually is made up of a number of plates, which rub against one another and move over time. Who’s to blame? I fault the liquid hot magma.
So what happens is that these plates slip against each other in one of three ways, as shown below,
and these cause earthquakes. But what’s going on deep down in these faults? Well, that’s what a team of scientists in Japan intend to figure out, and here’s the BBC news article about it!
Turns out that the biggest quakes (the magnitude 8 or 9 ones) mostly happen at sea. So they’re actually going to the sea floor, digging out cores that go over a kilometer deep (1.4 km, seriously!), and then bring them back to the lab to analyze them and try to understand what’s going on beneath the Earth’s skin. Here’s a picture:
This is basically like taking the Earth to the doctor and having it X-rayed to see what’s wrong with its insides. Now nothing’s wrong, of course, except from our perspective! (We tend to not like these natural disasters.) But by doing this, they’re able to make 3D maps of the Earth’s density, and figure out what’s likely to happen where. I don’t know that this will lead to one of the holy grails of geology, earthquake forecasting, but that’s the hope!
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