Semblance for microseismic event detection

0447771 - ÚSMH 2016 RIV GB eng J - Journal Article
Staněk, František - Anikiev, D. - Valenta, Jan - Eisner, Leo
Semblance for microseismic event detection.
Geophysical Journal International. Roč. 201, č. 3 (2015), s. 1362-1369. ISSN 0956-540X. E-ISSN 1365-246X
R&D Projects: GA ČR GAP210/12/2451
Institutional support: RVO:67985891
Keywords : microseismic event * microseismic monitoring * source mechanisms
Subject RIV: DC - Siesmology, Volcanology, Earth Structure
Impact factor: 2.484, year: 2015

Microseismic monitoring from large arrays using migration-based detection and location techniques is limited by detections of false positive events, which are the interpretation of spurious/noisy signals as real events. Therefore, semblance has been considered to differentiate between false positive and true events. However, semblance by itself is not suitable for variable signals such as those caused by shear source radiation. We present a new methodology for event detection and location using semblance of amplitudes corrected by a source mechanism. Our method is suitable for multichannel processing of microseismic data sets acquired with large arrays. The amplitudes are corrected by the radiation pattern of the inverted source mechanism before the semblance computation. We show that the source mechanism correction is the key factor in maximizing the value of semblance and makes the detection based on semblance superior to simple stacking. We apply this method to a data set recorded by a large surface star-like array on synthetic as well as on field data.
Permanent Link: http://hdl.handle.net/11104/0249522