TY - JOUR
T1 - Uncovering the Iceland hot spot track beneath Greenland
AU - Mordret, Aurélien
N1 - Publisher Copyright:
©2018. American Geophysical Union. All Rights Reserved.
PY - 2018/6
Y1 - 2018/6
N2 - During the past 120 Ma, the Greenland craton drifted over the Iceland hot spot; however, uncertainties in geodynamic modeling and a lack of geophysical evidence prevent an accurate reconstruction of the hot spot track. I image the Greenland lithosphere down to 200-km depth with both group and phase velocity seismic noise tomography. The 3-D shear wave velocity model obtained using 4–5 years of continuous seismic records from the Greenland Ice Sheet Monitoring Network is well resolved for most of the Greenland main island. The crustal part of the model clearly shows different tectonic units. The hot spot track is observed as a linear high-velocity anomaly in the middle and lower crust associated with magmatic intrusions. In the upper mantle, a pronounced low-velocity anomaly below the east coast might be due to the remnant effect of the Iceland hot spot when it was at its maximum intensity. Thermomechanical modeling suggests that this area has higher temperature and lower viscosity than the surrounding cratonic areas and experiences a higher than average surface heat flow. This new detailed picture of the Greenland lithosphere will drive more accurate geodynamic reconstructions of tectonic plate motions and help to better understand the North Atlantic tectonic history. Models of Greenland glacial isostatic adjustment will benefit from the 3-D upper-mantle viscosity model, which in turn will enable more precise estimations of the Greenland ice sheet mass balance.
AB - During the past 120 Ma, the Greenland craton drifted over the Iceland hot spot; however, uncertainties in geodynamic modeling and a lack of geophysical evidence prevent an accurate reconstruction of the hot spot track. I image the Greenland lithosphere down to 200-km depth with both group and phase velocity seismic noise tomography. The 3-D shear wave velocity model obtained using 4–5 years of continuous seismic records from the Greenland Ice Sheet Monitoring Network is well resolved for most of the Greenland main island. The crustal part of the model clearly shows different tectonic units. The hot spot track is observed as a linear high-velocity anomaly in the middle and lower crust associated with magmatic intrusions. In the upper mantle, a pronounced low-velocity anomaly below the east coast might be due to the remnant effect of the Iceland hot spot when it was at its maximum intensity. Thermomechanical modeling suggests that this area has higher temperature and lower viscosity than the surrounding cratonic areas and experiences a higher than average surface heat flow. This new detailed picture of the Greenland lithosphere will drive more accurate geodynamic reconstructions of tectonic plate motions and help to better understand the North Atlantic tectonic history. Models of Greenland glacial isostatic adjustment will benefit from the 3-D upper-mantle viscosity model, which in turn will enable more precise estimations of the Greenland ice sheet mass balance.
KW - ambient seismic noise
KW - Greenland
KW - hot spot track
KW - surface wave tomography
KW - thermomechanical model
UR - http://www.scopus.com/inward/record.url?scp=85050233742&partnerID=8YFLogxK
U2 - 10.1029/2017JB015104
DO - 10.1029/2017JB015104
M3 - Article
AN - SCOPUS:85050233742
SN - 2169-9313
VL - 123
SP - 4922
EP - 4941
JO - Journal of Geophysical Research: Solid Earth
JF - Journal of Geophysical Research: Solid Earth
IS - 6
ER -