A Comprehensive Earthquake Catalog for Iraq in Terms of Moment Magnitude

Abstract

A comprehensive earthquake catalog was compiled for Iraq and neighboring areas as part of a broader probabilistic seismic‐hazard assessment project. The Iraq Seismic Network (ISN) was established in 1976 and became operational in the early 1980s. However, recording and reporting of seismic data has been intermittent in Iraq. Hence, events were collected from various sources, including the ISN when available, International Seismological Centre (ISC), European‐Mediterranean Seismological Centre, U.S. Geological Survey Centennial Catalog, Global Centroid Moment Tensor solutions, and Ambraseys’ extensive work on cataloging of instrumental era earthquakes in the Middle East (e.g., Ambraseys, 1978, 2001, 2009). We supplement these with new direct moment magnitude calculations based on coda calibration technique. For many of the larger events in the catalog, more than one magnitude is available. Directly calculated moment magnitudes ( M w) were favored, followed by body‐wave magnitude ( m b) obtained from the ISC. Where no directly calculated M w was available, other magnitude scales were converted to M w using relationships compatible with the local catalog. The resulting earthquake catalog spans from the year 1900 until the end of 2009, covers the region bounded by 26°–40° N latitudes and 36°–51° E longitudes, and includes more than 18,000 earthquakes, of which roughly 4000 are M w 4.0 or larger.