Ground-truth (GT) seismic events are critical in seismic monitoring and discrimination, as they provide reference for obtaining well-constrained locations, testing existing velocity/attenuation models, and discriminating earthquakes, mining activities, and chemical/nuclear explosions. Well-located events are also essential for building 3D velocity models. Most GT events in the current International Association of Seismology and Physics of the Earth’s Interior (IASPEI) catalog are determined from seismic data and limited by the station coverage. In places with sparse seismic stations (e.g., the Mid East and Northeast Asia), GT events are few and far between, limiting our ability to monitor and discriminate seismic events in those regions. Furthermore, the current GT source information is usually limited to the location, origin time and magnitude. For waveform-based investigation, a complete GT source must include not only the location and origin time, but also the moment tensor. While the existing Centroid Moment Tensor (CMT) catalogs provide moment tensor solutions for large earthquakes, the earthquakes are usually not well located. The location errors, particularly in depth, affect the moment tensor solutions. So there is a large disconnect between the existing GT and CMT sources.
My group is collaborating with Professor Yang Shen at GSO and carrying out a pilot study to develop a new method that use both geodetic and seismic data to determine the earthquake source parameters and the associated uncertainties in southern Iran.