The region-specific TT curves – or the equivalent 1-dimensional velocity models they represent – can then be used as the base models for the more sophisticated 3-dimensional correction surfaces. More importantly, deriving region-specific piecewise linear TT curves (for later operational use) with a handful, well-designed, well-recorded GT0 events, is shown to be a cost-efficient, quick pay-off approach for seismic calibration. These joint experiments provide an invaluable suite of Ground-Truth “Zero” (GT0) data for calibration of regional seismographs in Central Asia with a variety of possible applications: improved mapping of seismicity for earthquake hazards reduction, fundamental research in seismology, and monitoring and verification of nuclear tests. Department of State also sponsored, via DTRA, a deployment of temporary seismographs along a profile between Semipalatinsk and Makanchi during the Omega-3 experiment. We find that for earthquakes above Mw 6, the most robust automatic inversions can usually be obtained using the W-Phase time window.The Defense Threat Reduction Agency, U.S.A., and the National Nuclear Center, Republic of Kazakhstan, jointly conducted a series of large chemical explosions between 19 at the former Semipalatinsk Test Site in the Eastern Kazakhstan. Additionally we provide solutions for smaller earthquakes above about Mw 4 in Europe, which are normally not analyzed by the GCMT project. Our published moment tensors are generally in good agreement with those published by the Global Centroid-Moment-Tensor (GCMT) project for earthquakes above a magnitude of about Mw 5. In those cases where a manual interaction is still required, the automatic inversion usually does a good job at pre-selecting those traces that are the most relevant for the inversion, keeping the work required for the analyst at a minimum. The automatic results are quite often good enough to be published without further improvements, sometimes in less than 30 minutes from origin time. This involves inversions that are performed automatically in near-real time, followed by analyst review prior to publication. This real-time bulletin is a product of the GEOFON Extended Virtual Network (GEVN) and credit belongs to all involved institutions Disclaimer: Unless revised by a geophysicist, automatically determined earthquake locations may be erroneous This bulletin is customizable and also available as RSS news feed. Moment tensors are currently computed in a semi-automatic fashion. An iterative centroid search can be performed independently both horizontally and in depth. The inversion is currently performed in the time domain only. Wave types include body, surface and mantle waves as well as the so-called 'W-Phase' (Kanamori and Rivera, 2008). The moment tensor inversion technique uses a combination of several wave types, time windows and frequency bands depending on magnitude and station distance. SC3 is developed by GFZ Potsdam with significant contributions from its user community. ![]() SeisComP 3 (SC3) is a software package for seismological data acquisition, archival, quality control and analysis. M 5 + earthquake epicentres from the USGS bulletin during 19512019. ![]() Christian-Albrechts-University Kiel, D-24118 Germany 4Institute for Geosciences, University of Potsdam, 14469 Germany Accepted 2022 Febr uar y 7. ![]() The software used to compute the moment tensors is a GFZ-Potsdam in-house development, which uses the framework of the software SeisComP 3 (Hanka et al., 2010). 2GFZ German Research Center for Geosciences, 14467 Potsdam, Germany. As part of its earthquake information service, GFZ Potsdam has started to provide seismic moment tensor solutions for significant earthquakes world-wide.
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