Satellite data could warn us of earthquakes days in advance

Scientists have taken another step towards developing an earthquake early warning system. According to new research, satellites orbiting the Earth are capable of detecting anomalies in the ground, atmosphere and ionosphere that eventually give rise to earthquakes. These anomalies, called earthquake precursors, have been detected by European and Chinese satellites up to 19 days before the disasters in the Mediterranean.

Following the 7.8 magnitude earthquake on the Turkey-Syria border in 2023, Dr. Mehdi Akhoondzadeh, an associate professor of remote sensing at the University of Tehran in Iran, wanted to see if working satellites detected the event in advance. He obtained data from China's Zhangheng 1, NASA's Aqua and Aura satellites, and the European Space Agency's three-satellite Swarm mission, and then compared it with earthquake data from the United States Geological Survey (USGS). The goal was to see if the Earth showed any warning signals before the actual earthquake, signals that could be used to issue evacuation orders before future tectonic events.

The USGS earthquake intensity data that Akhoondzadeh compared his satellite findings to.
Credit: USGS

According to a paper in it Magazine of applied geodesy, those warning signs were plentiful. Akhoondzadah's most interesting finding, he writes, was a temperature change in Earth's lithosphere (the planet's crust and the top layer of the upper mantle) 19 to 12 days before the Turkey-Syria earthquake occurred. (The AIRS instrument, or Atmospheric Infrared Sounder, aboard NASA's Aqua satellite provided this data.) Just a few days after that, Earth began showing water vapor, methane, ozone, carbon monoxide, and aerosol optical depth (AOD) anomalies that lasted about five days. Meanwhile, ionospheric changes took longer to manifest. While some appeared five days before the earthquake, the clearest signals from the ionosphere, such as electron density and temperature, were not detected until the day before the earthquake.

With this data, Akhoondzadah argues that lithospheric-atmospheric-ionospheric coupling, or LAIC, could be the secret to early earthquake detection. But more research (and, unfortunately, a few more earthquakes) will be needed before the LAIC can be considered a reliable earthquake warning mechanism. Meanwhile, researchers are working to develop earthquake detection methods that use gravitational waves either GPS time series data from minutes to hours before tectonic events. We may one day see this data being incorporated into a more advanced version of Shake alerta warning system that issues urgent alerts to mobile phones just before the onset of an earthquake.