P Wave Tomography Beneath Greenland and Surrounding Regions: 1. Crust and Upper Mantle

Genti Toyokuni, Takaya Matsuno, Dapeng Zhao

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)

Abstract

We study the 3-D P wave velocity (Vp) structure of the crust and upper mantle beneath Greenland and surrounding regions using the latest P wave arrival time data. The Greenland Ice Sheet Monitoring Network (GLISN), initiated in 2009, is an international project for seismic observation in these regions using 34 stations. We use a regional seismic tomography method to simultaneously invert P wave arrival times of local earthquakes and P wave relative traveltime residuals of teleseismic events. These data are extracted from the ISC-EHB catalog; however, for the teleseismic data, we picked new arrival times from seismograms using a cross-correlation method. Our tomographic results clearly reveal the Iceland plume, the Jan Mayen plume, and a newly discovered “Svalbard plume,” which merge together in the mantle transition zone. A high-Vp body exists beneath the Greenland Sea, which might act as an obstacle against the rising Svalbard plume. Furthermore, our results reveal a remarkable low-Vp anomaly elongated in the NW-SE direction at depths ≤250 km beneath central Greenland, which is connected with the Iceland and Jan Mayen hotspots. Although previous studies have suggested a similar feature, our result is the first to show the low-Vp zone existing at all depths in the Greenland lithosphere, and its spatial distribution coincides with a high heat flux region. These characteristics indicate that the low-Vp zone reflects residual heat from the Iceland plume when the Greenland lithosphere passed over this plume at ~80–20 Ma. Our results also indicate the possible existence of residual heat from the Jan Mayen plume.

Original languageEnglish
Article numbere2020JB019837
JournalJournal of Geophysical Research: Solid Earth
Volume125
Issue number12
DOIs
Publication statusPublished - 2020 Dec

Keywords

  • Greenland
  • Iceland hotspot
  • The Greenland Ice Sheet Monitoring Network (GLISN)
  • ancient heat track
  • crust and upper mantle
  • seismic tomography

ASJC Scopus subject areas

  • Geophysics
  • Geochemistry and Petrology
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science

Fingerprint Dive into the research topics of 'P Wave Tomography Beneath Greenland and Surrounding Regions: 1. Crust and Upper Mantle'. Together they form a unique fingerprint.

Cite this