Publications

Teleseismic Love and Rayleigh waves recorded by the GLATIS project (Greenland Lithosphere Analysed Teleseismically on the ice sheet) have been analysed for phase velocities using a two-station method. The data set consists of broad band recordings from 19 seismograph stations in Greenland, as well as data from IRIS station ALE in northern Canada. Four of the BB seismographs in Greenland are permanent, the rest are temporary with deployment periods ranging from three months to four years. We have obtained good quality phase velocities for Love and Rayleigh waves in the period range from 25 to 150 seconds for 45 different two-station paths across Greenland. This provides us with information about velocity heterogeneities through the entire lithosphere and covering a large part of central to southern Greenland. An isotropic tomographic inversion was used to combine the phase velocity information from the dispersion curves in order to produce phase velocity maps for Greenland at several different periods. The most significant lateral variation in phase velocity is found at intermediate periods, where a high-velocity anomaly is resolved beneath central-southwestern Greenland, and a low-velocity anomaly is found beneath southeastern Greenland. Results from Love and Rayleigh waves will be compared.

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Larsen, T. B.; Darbyshire, F. A.; Sørensen, M.; Dahl-Jensen, T.; Gudmundsson, O.; Gregersen, S.; Hanka, W.; Pedersen, H. A. (2004): Large Heterogeneities in the Greenland Lithosphere and upper Mantle. 1st General Assembly European Geosciences Union (Nice, France 2004).