Hidden signals under Earth’s crust could reveal future earthquakes

In the case of some large earthquakes, scientists say we could be tracking them years in advance with the right forecasting.

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Published: November 28, 2023 at 4:30 pm

Large earthquakes could be identified months or even years in advance by detecting unique seismic signals. That's according to new research from a team of German researchers.

The new research, published in Nature, suggests more accurate earthquake warning systems require more local and regional sites that can detect underground signals. Along with this, monitoring of second faults after the main rupturing fault would further increase the accuracy of these readings.

To find this out, the team led by Dr Patricia Martinez-Garzon studied the Kahramanamras earthquake that shook Turkey in early 2023. They found that there was an acceleration in the seismic event rates and larger energy release starting roughly eight months prior to the earthquakes.

These signals were detected in clusters within 65km of the epicentre. Although the main rupture occurred on a fault line and in an area that was known to be a hazard for earthquakes, signals prior to the event took place both on the main and secondary faults, which hadn’t received much attention from scientists in the past.

Some larger earthquakes can display a preparation phase (events occurring prior to the main earthquake) whose signals are monitorable, but the team notes that this can be challenging to follow with so many variables occurring at the same time.

Currently, short-term prediction of earthquake magnitude, time and location is just not possible. The scientists behind this study argue that long-term monitoring is crucial to help build our understanding of earthquakes and future events.

But not everyone, including Bill McGuire, professor of Geophysical and Climate Hazards at UCL, agrees with how useful this could be. "While this is interesting from a scientific viewpoint, it is unlikely that knowing a big earthquake might be on the way within months or years really gets us any further forward in preparing for them," he says.

"The only useful prediction of future seismic activity is arguably the one that accurately fixes the location of a coming quake and its timing to within a few weeks, so as to allow evacuation.

"In terms of reducing the impacts of a future quake, knowing one was on the way within months to years, would not provide the time to retrofit poorly constructed buildings."


About our expert

Professor Bill McGuire is a volcanologist, climate scientist, writer and broadcaster. He is an Emeritus Professor of Earth Sciences at University College London. McGuire was also a member of the UK Government's Natural Hazards Working Group, and a member of the Scientific Advisory Group for Emergencies (SAGE).

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