Rapid detection and characterization of large earthquakes using quasi-finite-source Green's functions in continuous moment tensor inversion

Abstract

Large earthquakes along subduction zones have the potential to generate tsunamis along local coasts, as well as traveling far across oceans. By continuously inverting for moment tensors we show that it is possible with a single procedure to automatically detect, locate and determine source parameters of any earthquake, from magnitude 3.5 to larger than 8 located in both the near‐ and far‐field. We find that the detection and characterization of large earthquakes is improved when quasi‐finite‐source Green's functions are used in a point‐source moment tensor approach as they represent to some extent the rupture's finiteness and directivity. Solutions can be obtained within several minutes after the origin time of the earthquake, and could therefore be used as part of a near‐source tsunami early warning system, capable of providing tens of minutes of possible warning depending on the distance of the earthquake rupture from the coast.

Stability of rapid finite‐fault inversion for the 2014 Mw6.1 South Napa earthquake

“…The method was then applied to earthquakes in Japan for fast and routine source analysis [ Tsuruoka et al ., ]. By introducing quasi‐finite‐source Green's functions into mechanism inversions, Guilhem and Dreger [] further improved Kawakatsu's method and expanded the scope of application. Recently, J .…”

Current challenges in monitoring, discrimination, and management of induced seismicity related to underground industrial activities: A European perspective

“…Natural earthquakes are generally characterized by nearly pure double-couple (DC) source mechanisms (non-DC earthquakes have been observed in nature, due to the simultaneous rupture of properly oriented multiple faults, e.g., Miller et al [1998], Frohlich [1990], and Frohlich et al [1989]), whereas in some cases the presence of an important non-DC component has provided a characteristic indicator of induced seismicity [Sileny et al, 2009;Cesca et al, 2013b;Guilhem et al, 2014;Zhang et al, 2016;Martínez-Garzón et al, 2017]. However, moment tensor inversion procedures are still challenging for microseismic events [Cesca and Grigoli, 2015] for the lack of 3-D models and widely adopted inversion tools Reviews of Geophysics 10.1002/2016RG000542 for 3-D media, which are needed to model high-frequency waveforms [Guilhem and Dreger, 2011]. For these reasons this discrimination approach can be applied only to large seismic events, generally with magnitude M L > 3 [Guilhem et al, 2014] and resolve non-DC terms.…”

On the Systematic Long-Period Noise Reduction on Ocean Floor Broadband Seismic Sensors Collocated with Differential Pressure Gauges

“…This period range is essential for several applications: structural studies using surface waves as well as moment tensor inversion of regional earthquakes. In particular, rapid moment tensor determination of regional earthquakes is one of the crucial components in real-time earthquake hazard assessment in regions such as California (Sipkin, 1982;Dreger and Helmberger, 1991;Romanowicz et al, 1993;Dreger and Romanowicz, 1994;Pasyanos et al, 1996;Tajima et al, 2002;Ichinose et al, 2003;Clinton et al, 2006;Guilhem and Dreger, 2011). This is also the period range of choice for studies of regional structure using surface waves.…”