Crust and upper mantle structure of the New Madrid Seismic Zone: Insight into intraplate earthquakes

Chuanxu Chen, Dapeng Zhao, Shiguo Wu

Research output: Contribution to journalArticle

34 Citations (Scopus)

Abstract

We determine a 3-D P-wave velocity model of the crust and upper mantle down to 400km depth to investigate structural heterogeneity and its influences on the generation of intraplate earthquakes in the New Madrid Seismic Zone. We used 4871 high-quality arrival times from 187 local earthquakes and 30,846 precise travel-time residuals from 1041 teleseismic events recorded by the EarthScope/USArray Transportable Array. Our results show that, beneath the Reelfoot rift, a significant low-velocity (low-V) zone exists in the upper mantle down to 200km depth, with a large volume of 200×200×150km3. The origin of the low-V zone may be related to the passage of the Bermuda hotspot and the stalled ancient Farallon slab materials foundering in the mantle transition zone. This low-V zone may have relatively low shear strength and act as a viscously weak zone embedded in the lithosphere, being apt to concentrate tectonic stress and transfer stress to the seismogenic faults in the upper crust, leading to the large intraplate earthquakes in the New Madrid Seismic Zone.

Original languageEnglish
Pages (from-to)1-14
Number of pages14
JournalPhysics of the Earth and Planetary Interiors
Volume230
DOIs
Publication statusPublished - 2014 May

Keywords

  • Farallon slab
  • Intraplate earthquakes
  • Low-velocity zone
  • New Madrid Seismic Zone
  • Seismic tomography
  • Seismotectonics

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Geophysics
  • Physics and Astronomy (miscellaneous)
  • Space and Planetary Science

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