Identification and Validation of Reference Events Within the Area Regionally Monitored by IMS Stations in Asia and North Africa
Abstract
A database of seismic networks and stations, including their operational history, has been compiled from all sources. In particular, the name, coordinates and elevations of seismic stations that have operated or are presently operating in Iran, India and China have been compiled. Seismic stations that have a long history of reporting phase data have been identified and validated. A new groomed version of the ISC/NEIC bulletin database for the period 1964-2000 has been used to identify and investigate potential reference events that meet GT5 criteria. A new algorithm that uses the new station database to identify potential reference events meeting GT5 criteria based solely on the distribution of potential reporting stations has been developed and implemented. High-resolution cluster analysis has been refined and applied to known earthquake sequences and to nuclear explosion sites in Asia and North Africa for which one or more of the associated events is known to GT5 accuracy. Visits by scientists from China, Iran and India have enabled us to identify new sources of reference events in those countries and to familiarize them with applications of the Hypocentroidal Decomposition (HDC) method. Regional arrival time data for stations in those countries for the Lop Nor, Chamoli and Bhuj clusters was obtained. A well-located GT5 data set of explosions and earthquakes was used to develop epicenter accuracy criteria for near-regional, regional, and teleseismic distance ranges. The cluster event catalogs and derived parameters, such as empirical estimates of source-station path anomalies, has provided a reference data set that has been used in experiments designed to validate a 3-D model of the region of interest.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 2004
- Accession Number
- ADA427872
Entities
People
- Eric A. Bergman
- Eric R. Engdahl
Organizations
- University of Colorado Boulder