Our science reporter Esme Stallard.

is in the newsroom with more.

So Esme, talk us through what we know has happened.

So there was this 7.7 earthquake.

What do we mean by that?

That's a measure of momentum.

Effectively, it's a measure of how much movement there has been in the top layer of the earth and what size has moved.

So the earth crust is split into lots of different plates and they're all moving constantly.

And Myanmar is at the confluence of four of these plates and so it's a very tectonically active region.

So we had the main earthquake that occurred about 6:30 GMT around lunchtime local time.

And then there was a series of aftershocks.

which then occurred affecting the neighboring countries.

But I want to talk a little bit more.

about that tectonic plate movement that I mentioned.

I'm just going to show you this map here behind me, which is from the US Geological Survey.

And the dot here highlighted in blue was that first initial earthquake that I mentioned.

But then what happens when you get that movement then settling is that you get then these aftershocks.

For example, there was another one here just south just 10 minutes later, which occurred again, that was very significant.

It was more than six on that same scale.

Now, when I mentioned before those plates, what we can see here is we can see a major red line coming down close to where the earthquakes occurred.

That's a major fault line.

So that's where some of that movement is happening.

And the US Geological Survey says that the kind of conditions or characteristics of this earthquake suggest that maybe some of that movement was occurring along that fault line.

That's known as the Saga fault.

And it's named off the area local to it. And then either side you've got here the Indian plate and then over here the Eurasian plate and they're also moving.

And so this is why this area is very prone to earthquakes.

But the sheer scale of it is quite unusual, the reason that we think it was so significant is that this earthquake happened at a very low area below the cross.

So it's only 10 kilometers down.

That's a very shallow earthquake.

And that means when you get a lot of that movement between the plates, it really has a big effect on the surface.

In terms of can we look at previous earthquakes?

Can they indicate potentially the scale?

When we look at other earthquakes of this size, we have seen significant fatalities.

And I think that is why it's such a concern for local authorities and rescue services at this time.

Um there's also, you know, mentioned just there the concern about further aftershocks.

So we've seen some more, those are the other orange dots here occurring.

So there is still the risk at this time that there will be further earthquakes felt.

But you can understand considering the kind of surrounding geology why this occurred.

Esme, thank you very much for that detail.

Esme Stallard, who is our science reporter with detail of what we know about that 7.7 magnitude quake.

As she was saying, the epicenter is in Myanmar and it is difficult to get information and pictures out because we know that power lines are down.

Communication is difficult and also the fact that it is under military control since the coup.