PARTIAL SUPPORT OF THE INTERNATIONAL SEISMOLOGICAL CENTRE

International Seismological Centre, Thatcham

Investigators

Abstract

This grant allows for renewed partial support of operations of the International Seismological Centre (ISC). The ISC is internationally supported and the requested budget is based on the relative GDPs of sponsor countries with funding from the U.S. near 20% of the estimated operational costs over this period. Support provides for continued production of the ISC Bulletin - the definitive global summary of earthquake hypocentres, magnitudes and source mechanisms, as well as station arrival times, amplitudes and other measurements with links to original waveforms where available. The international supported and non-governmental affiliation of the ISC allows the Centre to collect and freely distribute data from otherwise unavailable sources of global seismic recordings. The ISC Bulletin supports the global seismology community for fundamental research on Earth structure, earthquake physics and earthquake hazards mitigation. The Bulletin also aids in monitoring of the Comprehensive Test Ban Treaty. ISC data products, in particular the global catalog of observed arrival times, amplitudes, and associated meta data, are a starting point for fundamental studies of Earth structure and earthquake source mechanisms. Support under this grant will allow for continued development and refinement of seismic event parameters that are published in the ISC bulletin and available on line as well as new efforts to extend the catalog back in time to the 1900 (pre-digital seismic recordings) and to a lower magnitude threshold. The improved seismic event records will allow for improved understanding of historical global seismicity and lead to better models of Earth's interior structure, the later critical to identifying seismic event source mechanisms, magnitudes and locations that aid in comprehensive nuclear test ban treaty monitoring. ISC products are critical to maintaining definitive accurate seismic event provenance over decadal time scales and contribute to improved earthquake resistant civil engineering globally. Specific tasks to be supported include: 1) ongoing collection, automatic merging and association of reported bulletin data from networks and data centers around the world, including National Earthquake Information Center (NEIC), USArray, Comprehensive Test Ban Treaty Office (CTBTO), Japanese Meteorological Agency (JMA) etc.; 2) manual review of hypocentres, phase readings, and related data for events simultaneously reported by several networks approximately of magnitude 3.5 and above; 3) distribution of the ISC Bulletin by means of the web-search, ftp, CD-ROMs and the printed ISC Bulletin Summary; 4) maintenance and re-development of the International Seismograph Station Registry jointly with the National Earthquake Information Center operated by the US Geological Survey and in coordination with the Federation of Digital Seismograph Networks (FDSN); 5) maintenance and update of the International Association of Seismology and Physics of the Earth's Interior (IASPEI) Collection of Reference Events (GT0-5); 6) partial support for extension of the ISC-GEM Global Instrumental Earthquake Catalogue -- the most homogeneous global long-term catalog used for global and regional seismic hazard assessment; and 7) maintenance and extension of the ISC Event Bibliography, which allows for rapid literature searches pertaining to significant global seismic events. ***