Geodetic Catalogue of Earthquake Deformation: the LiCSAR Earthquake Data Provider

Abstract:

Global seismological catalogues are now a long-established record of world-wide seismic events, which provide important starting points for many follow-on studies in terms of source locations and fault parameters. Until recently, the use of geodetic datasets (particularly InSAR) for measuring deformation associated with moderate to large earthquakes has been on a case-by-case basis performed by individual research groups globally. However, there has not been an established systematic catalogue of land surface deformation associated with capturing all applicable continental and subduction related moderate and major events until this year.

Here we present one such emerging catalogue of earthquake deformation using the LiCSAR processing system from COMET, which harnesses the global land coverage of ESA’s Sentinel-1 SAR products. Following magnitude 5.5+ shallow continental and larger subduction zone earthquakes, we create an individual event webpage that indicates which pending data will be processed. Interferometric products are then served through a web portal to end users and form a long-term catalogue of the coseismic deformation for these events. The LiCSAR Earthquake Data Provider is triggered by USGS alerts and acts in near-real time, with latencies from when data has been ingested by ESA of a few hours. Depending upon the size of the event, the processing of postseismic data continues for weeks to months following the mainshock. There are almost 50 events covering the past year, with new events continually be added.

The catalogue broadens the accessibility of earthquake deformation data by increasing the speed with which it is available to other researchers without the need to deal with complexities of interferometric processing (particularly for large areas in the case of major events). This can be particularly useful for those deployed to the field where remotely sensed datasets can facilitate field campaigns. It also offers the prospective of being incorporated into disaster response, and the longer-term disaster risk management cycle. Next steps involve analysis of times series approaches to improve estimates of coseismic deformation and automation of modelling of individual events to provide fault parameters and uncertainties to establish a geodetic catalogue of earthquake solutions.