Damage and Displacement Maps from Spaceborne Synthetic Aperture Radar Observations for Türkiye-Syria Earthquake Response and Recovery

The Mw7.8 February 6, 2023 Turkey-Syria earthquake (and its aftershock sequence) was the deadliest earthquake in the modern history of Turkey and Syria. The event killed over 59,000 people, left 1.5 million people homeless, and affected about 14 million people (The Wall Street Journal, 12 Feb 2023). The combined estimated economic loss is about US$119 billion (AFP, 20 Mar 2023 et al.), which makes it the fourth-costliest earthquake on record. The extent and severity of the damage caused by the earthquake provide critical information for response but were extremely difficult to estimate at the early stage of response due to widespread damage, communication loss, and various weather conditions over large areas that obscure optical satellite images. Two days after the earthquake, The Earth Observatory of Singapore Remote Sensing Lab (EOS-RS) produced and disseminated the first Damage Proxy Map (DPM) of the impacted area using the Synthetic Aperture Radar observations by the ALOS-2 satellite operated by the Japan Aerospace Exploration Agency (JAXA), covering 70 km x 235 km, including Kahramanmaraş, one of the hardest-hit cities. Within ten days from the earthquake, we produced and released eight DPMs of the entire severely affected areas including Antakya, covering 204,000 km2, also using the SAR data from the Copernicus Sentinel-1 satellite operated by the European Space Agency (see figure). The maps were used by the Emergency Management Center in Ankara, Türkiye, as guidance for ground observations, by the United Nations World Food Programme for estimating the number of people affected, and by many other response agencies and NGOs for response and recovery. Within 24 hours of release, the first DPM was accessed more than 7,000 times from Türkiye, 5,000+ times from Japan, and 3,000+ times from the United States. We also produced detailed surface displacement maps from spaceborne SAR and optical imagery, measuring up to about 9 meters of lateral ground motion along the surface ruptures.