Scientists Create Global Map that Predicts Locations for Giant Earthquakes

Want to know what places are most likely to have a giant earthquake? Now you can. Researchers have created a new global map of subduction zones, illustrating which ones are predicted to be capable of generating giant quakes and which ones are not.

Most earthquakes occur at the boundaries between tectonic plates which cover the Earth's surface. The largest earthquakes on Earth, though, occur at subduction zones. These boundaries occur where one plate sinks below the other into Earth's interior. So far, researchers have recorded giant earthquakes for only a limited number of subduction zone segments. That said, records only go back to about 19000, so it's difficult to say whether one region is less likely to produce a massive quake than another.

"The main question is, are all subduction segments capable of generating giant earthquakes, or only some of them? And if only a limited number of them, then how can we identify these," askedWouter Schellart, one of the researchers, in a news release.

In order to investigate these questions, the researchers examined earthquake data going back to 1900 in addition to data from subduction zones in order to map the maint characteristics of all active subduction zones on Earth. They then investigated if subduction segments that have experienced giant earthquakes in the past share commonalities in their physical, geometrical and geological properties.

So what did they find? It turns out that the main indicators include the style of deformation in the plate overlying the subduction zone, the level of stress at the subduction zone, the dip angle of the subduction zone as well as the curvature of the subduction zone plate boundary and the rate at which it moves. By analyzing these features, the researchers were able to identify several subduction zone regions capable of generating giant earthquakes. These include the Lesser Antilles, Mexico-Central America, Greece, the Makran, Sunda, North Sulawesi and Hikurangi.

"For the Australian region subduction zones of particular significance are the Sunda subduction zone, running from the Andaman Islands along Sumatra and Java to Sumba, and the Hikurangi subduction segment offshore the east coast of the North Island of New Zealand," said Schellart in a news release. "Our research predicts that these zones are capable of producing giant earthquakes."

The findings reveal exactly where these giant earthquakes are most likely to occur. This, in turn, could help researchers in the future and could allow seismologists to better predict quakes.

The findings are published in the journal Physics of the Earth and Planetary Interiors.