TY - JOUR
T1 - High-Resolution Rayleigh Wave Group Velocity Variation Beneath Greenland
AU - Pourpoint, Maeva
AU - Anandakrishnan, Sridhar
AU - Ammon, Charles J.
N1 - Funding Information:
This work was supported by the U.S. National Science Foundation (grants EAR-1246776 (M. P. and S. A.)). The data were collected and distributed by the Greenland Ice Sheet Monitoring Network (GLISN) federation and its members. Major funding for GLISN is provided by the U.S. National Science Foundation, Geological Survey of Denmark and Greenland, Swiss Science Foundation, Helmholtz Centre Potsdam GeoForschungsZentrum, Centre National de la Recherche Scientifique and the French Ministry of Research, Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research, and the Korean Polar Research Institute. All GLISN partners provide contributions of equipment, operating costs, and/or data management. GLISN is made possible by the dedicated efforts of many field and support staff. The time series and metadata used in this study are open access and available through the facilities of the IRIS DMC (IRIS Data Management System). When available, the DOIs for permanent and temporary networks used in this study have also been listed in the references. IRIS is funded through the National Science Foundation through the Instrumentation and Facilities Program of the National Science Foundation under cooperative agreement EAR-1063471. The National Earthquake Information Center Advanced National Seismic System Comprehensive Catalog and the Global Centroid Moment Tensor Project Catalog were used to construct lists of earthquakes used in our analyses. We thank Nick Holschuh for valuable discussions. We also thank the Editor, reviewers Göran Ekström and Tine Larsen, and anonymous reviewers for their helpful comments.
Publisher Copyright:
©2018. American Geophysical Union. All Rights Reserved.
PY - 2018/2
Y1 - 2018/2
N2 - We present a high-resolution group velocity model of Greenland from the analysis of fundamental mode Rayleigh waves. Regional and teleseismic events recorded by the Greenland Ice Sheet Monitoring Network seismic network were used and we developed a group velocity correction method to estimate the dispersion within our region of study. The global dispersion model GDM52 from Ekström (2011, https://doi.org/10.1111/j.1365-246X.2011.05225.x) was used to calculate group delays from the earthquake to the boundaries of our study area. An iterative reweighted generalized least squares approach was then used to invert for the regional group velocity variations between periods of 25 s and 180 s. The group delay correction method helps alleviate the limitations of the sparse Greenland seismic network in a region with poor seismicity. Both the ray coverage and resolution of our model are significantly better than similar studies of Greenland using two-station methods. Spike tests suggest that features as small as 200 km can be resolved across Greenland. Our dispersion maps are consistent with previous studies and reveal many signatures of known geologic features including known sedimentary basins in Baffin Bay, the West and East Greenland flood basalt provinces, the East and South Greenland Archean blocks. Our model also contains two prominent features: a deep high-velocity anomaly extending from northwestern to southwestern Greenland that could be the signature of a cratonic root and a low-velocity anomaly in central eastern Greenland that correlates with the Icelandic plume track and could be associated with lithospheric thinning and upwelling of hot asthenosphere material.
AB - We present a high-resolution group velocity model of Greenland from the analysis of fundamental mode Rayleigh waves. Regional and teleseismic events recorded by the Greenland Ice Sheet Monitoring Network seismic network were used and we developed a group velocity correction method to estimate the dispersion within our region of study. The global dispersion model GDM52 from Ekström (2011, https://doi.org/10.1111/j.1365-246X.2011.05225.x) was used to calculate group delays from the earthquake to the boundaries of our study area. An iterative reweighted generalized least squares approach was then used to invert for the regional group velocity variations between periods of 25 s and 180 s. The group delay correction method helps alleviate the limitations of the sparse Greenland seismic network in a region with poor seismicity. Both the ray coverage and resolution of our model are significantly better than similar studies of Greenland using two-station methods. Spike tests suggest that features as small as 200 km can be resolved across Greenland. Our dispersion maps are consistent with previous studies and reveal many signatures of known geologic features including known sedimentary basins in Baffin Bay, the West and East Greenland flood basalt provinces, the East and South Greenland Archean blocks. Our model also contains two prominent features: a deep high-velocity anomaly extending from northwestern to southwestern Greenland that could be the signature of a cratonic root and a low-velocity anomaly in central eastern Greenland that correlates with the Icelandic plume track and could be associated with lithospheric thinning and upwelling of hot asthenosphere material.
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U2 - 10.1002/2017JB015072
DO - 10.1002/2017JB015072
M3 - Article
AN - SCOPUS:85041904289
SN - 2169-9313
VL - 123
SP - 1516
EP - 1539
JO - Journal of Geophysical Research: Solid Earth
JF - Journal of Geophysical Research: Solid Earth
IS - 2
ER -