Turkey earthquake fault lines mapped from space

February 11, 2023 8:20 am

[Source: BBC News]

It seems almost insensitive to start to have a deep dive into the science behind Monday’s earthquake events in Turkey.

More than 22,000 people are already confirmed dead and an unknown number still lie trapped, with the window for their rescue closing rapidly.

And yet the science will go on. The insights gleaned from this event will save lives in the future.

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Take a look at the map on this page. It is the most precise yet produced of how the ground lurched in response to the enormous energies that were unleashed.

The data behind it was acquired in the early hours of Friday by the European Union’s Sentinel-1A satellite as it traversed north to south over Turkey at an altitude of 700km (435 miles).

The Sentinel carries a radar instrument that is able to sense the ground in all weathers, day and night.

It is routinely scanning this earthquake-prone region of the world, tracing the often very subtle changes in elevation at the Earth’s surface.

Except, of course, the changes on Monday were not subtle at all; they were dramatic. The ground bent, buckled and in places ripped apart.

The red colours here describe movement towards the satellite since it last flew over the country; the blue colours record the movement away from the spacecraft.

It is abundantly clear how the ground has been deformed along and near the East Anatolian Fault line.

For both the Magnitude 7.8 quake that struck first on Monday at 01:17 GMT and the Magnitude 7.5 event at 10:24, the motion is “left-lateral”. That is to say: whichever side of the fault you are on, the other side has moved to the left. And by several metres in places.

The shocking thing is that the lines of rupture have gone right through settlements; in lots of places they will have gone right through buildings.

The Sentinel map will help scientists understand exactly what happened on Monday, and this knowledge will feed into their models for how earthquakes work in the region, and then ultimately into the risk assessments that the Turkish authorities will use as they plan the recovery.

There is sure to be a lot of discussion about how the two major tremors were related and what that could mean for further instability.

The map was processed by the UK Centre for Observation and Modelling of Earthquakes, Volcanoes and Tectonics (Comet). Its director, Prof Tim Wright, said the Sentinel observations vividly brought home the scale of the forces involved.