Shallow crustal imaging using distant, high-magnitude earthquakes

van IJsseldijk, J.E.; Ruigrok, Elmer; Verdel, Arie; Weemstra, C.

doi:10.1093/gji/ggz343

Shallow crustal imaging using distant, high-magnitude earthquakes

Title

Shallow crustal imaging using distant, high-magnitude earthquakes

Author

van IJsseldijk, J.E. (TU Delft Applied Geophysics and Petrophysics)
Ruigrok, Elmer (Universiteit Utrecht; Royal Netherlands Meteorological Institute (KNMI))
Verdel, Arie (TNO)
Weemstra, C. (TU Delft Applied Geophysics and Petrophysics; Royal Netherlands Meteorological Institute (KNMI))

Date

2019

Abstract

Global phases, viz. seismic phases that travel through the Earth?s core, can be used to locally image the crust by means of seismic interferometry. This method is known as Global Phase Seismic Interferometry (GloPSI). Traditionally, GloPSI retrieves low-frequency information (up to 1 Hz). Recent studies, however, suggest that there is high-frequency signal present in the coda of strong, distant earthquakes. This research quantifies the potential of these high-frequency signals, by analysing recordings of a multitude of high-magnitude earthquakes (≥6.4M_w) and their coda on a selection of permanent USArray stations. Nearly half of the P, PKP and PKIKP phases are recorded with a signal-to-noise ratio of at least 5 dB at 3 Hz. To assess the viability of using the high-frequency signal, the second half of the paper highlights two case studies. First, a known sedimentary structure is imaged in Malargue, Argentina. Secondly, the method is used to reveal the structure of the Midcontinent Rift below the SPREE array in Minnesota, USA. Both studies demonstrate that structural information of the shallow crust (≤5 km) below the arrays can be retrieved. In particular, the interpreted thickness of the sedimentary layer below the Malargue array is in agreement with earlier studies in the same area. Being able to use global phases and direct P-phases with large epicentral distances (>80°) to recover the Earth?s sedimentary structure suggests that GloPSI can be applied in an industrial context.

Subject

Body wave
Crustal imaging
Seismic interferometry

To reference this document use:

http://resolver.tudelft.nl/uuid:cbc7912f-397f-4190-af85-7d63e9b581cc

DOI

https://doi.org/10.1093/gji/ggz343

ISSN

0956-540X

Source

Geophysical Journal International, 219 (2), 1082-1091

Part of collection

Institutional Repository