February 2023, Turkey–Syria earthquakes
On Monday, February 6 2023, two major earthquakes with a magnitude greater than 7 on the Richter scale struck Turkey and Syria . The first earthquake occurred along the Anatolian fault (N60) and its extension to the Dead Sea fault, the Karazu fault (N25). The second earthquake is located north of the first, along the Sürgü-Çartak fault (N100).
Organizations and programs mobilized urgently
- The International Space and Major Disasters Charter, on Turkey from February 6 at 7 a.m., then 2 hours later on Syria.
- The Copernicus Emergency Mapping Service, whose Pléiades and Pléiades NEO satellites are programmed urgently. The first Pléiades images were acquired the day after the disaster.
- The emergency device CIEST 2 (Cell of Intervention and Scientific and Technical Expertise) to allow the scientific analysis of this catastrophe, made it possible to acquire stereoscopic images. This intervention and expertise cell is a synergy of the French community MDIS (Measurement of Deformations by Spatial Imagery) of ForM@Ter for the interpretation and understanding of geophysical phenomena from spatial data in order to respond quickly during ‘a natural disaster.
Earth observation: a major tool in the field of natural hazards
Scientific work within DATA TERRA’s Formater hub, dedicated to solid earth, is mainly collected by Earth observation satellites such as the Copernicus program (Sentinel 2) and Pléiades satellite images (Airbus/Cnes), but also includes observations made on the ground by large arrays of geophysical and geochemical instruments.
To assess the deformation of the ground in the disaster area , the calculation services of Form@ter were mobilized. The GDM-OPT services (Ground Deformation Monitoring with OPTical image time series) have been developed as part of the ForM@Ter data and services center by EOST with the contribution of IGN , IPGP , ONERA and OSUG.
They allow on-demand processing of Sentinel-2 image time series without having to download the images. GDM-OPT is declined in three services according to target scientific applications, including GDM-OPT-ETQ to quantify co-seismic deformations triggered by earthquakes of significant magnitude.
Discover a first product from the GDM-OPT-ETQ calculation service
These maps contribute significantly to the identification and mapping of surface fractures and determine displacement along faults. Spatial shifts of the order of 3 to almost 10 m are identified with a large geographic variability along the faults.
The DSM-OPT service ( Digital Surface Models from OPTical stereoscopic very-high resolution imagery ) is also accessible via the portal of the ForM@Ter hub of Data Terra. DSM-OPT allows the calculation of Digital Surface Models from stereo/tri-stereo Pléiades images directly from the catalog of the DINAMIS institutional system. This service is operated by the ForM@Ter hub, in collaboration with the THEIA hub (land surfaces) and the DINAMIS device , with the contribution of IGN/MATIS and IPGP .
Concerning the monitoring of telluric hazards, the service is connected to the CIEST2 system of ForM@Ter. When images are acquired following the device activation request, DSM-OPT is automatically launched with these images as input and the results are shared within the community.
DSM-OPT is accessible to the French scientific and institutional community through the ForM@Ter portal as well as to the international scientific community and other users on the Geohazard Exploitation Platform (GEP/ESA). It is also accessible to anyone with a ForM@Ter or Theia account.
The GDM-OPT and DSM-OPT web services make it possible to quantify with great precision the co-seismic deformations triggered by earthquakes of significant magnitude.
FLATSIM (ForM@Ter LArge-scale multi-Temporal Sentinel-1 InterferoMetry processing chain), is also a calculation service used in the study of earthquakes. It is a systematic calculation service in radar interferometry (InSAR) from time series of Sentinel-1 images, used to study the pre-earthquake context.
The Form@ter hub works in close collaboration with the Theia hub as well as the DINAMIS device. They are also involved in scientific work related to risks such as earthquakes causing considerable damage. The research questions related to the “risks” concern the entire information processing chain, from data acquisition to information restitution, as well as at the level of extraction methods. information, inventory and characterization of issues through the use of time series (sentinel, Pleiades, etc.) and hazard modelling.
Some examples of work carried out around earthquakes:
Processing performed on post-event images acquired by Pléiades PHR1A using CIEST².
Work carried out by Simon Gascoin, researcher at Cesbio and member of the scientific council of the Theia hub.
From Sentinel-1 radar imagery, linking ground movements and the probable damage caused to homes and buildings.
Dinh Ho Tong Minh, researcher at UMR TETIS, INRAE, work carried out for the Theia cluster
The Pléiades and Pléiades NEO satellites are scheduled urgently. The first Pléiades images were acquired the day after the disaster and enabled the production of a set of cartographic products by the Sertit/I-Cube.
All Pléiades data is returned to the DINAMIS Catalogue.
More useful links :
- CIEST²: https://www.poleterresolide.fr/ciest-2-nouvelle-generation-2/
- ForM@ter services developed in response to the earthquake: https://www.poleterresolide.fr/seisme-en-turquie-premiers-resultats-issus-des-services-de-calcul-de-formter/
- S.Gascoin maps: https://labo.obs-mip.fr/multitemp/antakya-before-and-after-the-earthquakes/
- DINAMIS article: https://dinamis.data-terra.org/seisme-turquie-syrie-limmensite-de-la-catastrophe/
