Low-frequency earthquakes in the Mexican Sweet Spot | INSTITUT DE PHYSIQUE DU GLOBE DE PARIS

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  Low-frequency earthquakes in the Mexican Sweet Spot

Type de publication:

Journal Article

Source:

Geophysical Research Letters, Volume 40, Ticket 11, p.2661-2666 (2013)

ISBN:

0094-8276

URL:

http://onlinelibrary.wiley.com/doi/10.1002/grl.50561/abstract?systemMessage

Mots-clés:

UMR 7154 ; Sismologie ; low-frequency; earthquakes; tremor; slow-slip; mexico; subduction

Résumé:

[1] We use data from the Meso-America Subduction Experiment to detect and locate low-frequency earthquakes (LFEs) in the Mexican subduction zone. We use visually-identified templates to perform a network waveform correlation search that produced ~17,000 robustly detected LFEs that form 15 distinct families. Stacking an LFE family's corresponding detections results in seismograms with high signal-to-noise ratios and clear P and S wave arrivals; we use these travel times to locate the sources. The resulting locations superpose a previously identified region of permanent non-volcanic tremor (NVT) activity. Husker et al. (2012) called this region a Sweet Spot, suggesting that the local conditions are adequate to continuously generate NVT. The LFE hypocenters have been located at a depth of 40–45 km in an area that is surrounding the upper slab-plate interface. We characterize their focal mechanisms by comparing their stacked seismograms to synthetic seismograms. This analysis reveals a common low-dipping focal mechanism.

Notes:

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