Depth and source mechanism estimation for special event analysis, event211 screening, and regional calibration

摘要

We have summarized the advantages and disadvantages of a variety of techniques211u001efor depth and mechanism estimation and suggest that significant work remains to 211u001ebe done for events with magnitudes of interest for test ban monitoring. We also 211u001edescribe a new, waveform modeling-based tool for fast and accurate, high-211u001eresolution depth and mechanism estimation. Significant features of this tool 211u001einclude its speed and accuracy and its applicability at relatively high 211u001efrequencies. These features allow a user to rapidly determine accurate, high-211u001eresolution depth estimates and constraints on source mechanism for relatively 211u001esmall magnitude (mb-4.5) events. Based on the accuracy of depth estimates 211u001eobtained with this tool, we conclude it is useful for both the analysis of 211u001eunusual or suspect events and for event screening. We also find that this tool 211u001eprovides significant constraints on source mechanism and have used it to develop 211u001e'ground-truth' estimates of depth and mechanism for a set of events in the Middle 211u001eEast and North Africa. These 'ground-truth' depths and mechanisms should be 211u001euseful for regional calibration.