Aegean Sea Earthquake October 2020
On Friday, October 30, a magnitude 6.6 - 7.0 earthquake occurred in the Aegean Sea between Turkey and the Greek Islands. The earthquake’s epicenter was just north of Samos, Greece, but the most significant impacts were felt further north in Izmir, Turkey. The earthquake caused flooding and significant damage to the city, and was responsible for numerous casualties according to media reports.
The NASA Earth Applied Sciences Disasters Program has activated in support of the event, and is working to determine what NASA resources and capabilities may be available to aid response and recovery. The Program provided damage proxy maps (DPMs) showing potential damage to structures, and displacement maps showing surface movement from the earthquake, to the U.S. Geological Survey (USGS) and seismologists in Turkey. The Program is also working with stakeholders from the Turkish Space Agency and several universities in the region.
Synthetic aperture radar (SAR) data collected by satellites lets scientists compare ground surface changes from before and after a major event. NASA's Advanced Rapid Imaging and Analysis (ARIA) team produced the above DPM showing areas in Izmir, Turkey that were likely damaged from the earthquake. DPMs can be used as guidance to identify damaged areas, but may be less reliable over vegetated areas. This map is most sensitive to building damage, but small-scale change or partial structural damage may not be detected in some cases. Preliminary validation of the data was done by comparing with the data with media reports.
The ARIA team also produced a displacement map using some of the same SAR data, which identifies where and how much the ground moved due to the earthquake. The western part of the Greek island of Samos moved upward by as much as 10 cm, and a small area of the north coast of Samos moved downward by roughly the same amount. This pattern of movement is consistent with a fault sloping from the north coast of Samos to the north to the location where the earthquake rupture started. Please note that this displacement map is a preliminary product and not yet been validated. The map can be used as guidance to identify areas of significant ground displacement, but may be less reliable over heavily vegetated areas and steeper slopes.
ARIA is a collaboration between NASA's Jet Propulsion Laboratory (JPL) and the California Institute of Technology (Caltech). It is funded in part by the Disasters program area of NASA Earth Applied Sciences through the NASA ROSES A.37 research project “Global Rapid Damage Mapping System with Spaceborne SAR Data”.