Ice cap melting and low-viscosity crustal root explain the narrow geodetic uplift of the Western Alps
International audience More than 10 years of geodetic measurements demonstrate an uplift rate of 1–3 mm/yr of the high topography region of the Western Alps. By contrast, no significant horizontal motion has been detected. Two uplift mechanisms have been proposed: (1) the isostatic response to denud...
Published in: | Geophysical Research Letters |
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Main Authors: | , , |
Other Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2016
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Subjects: | |
Online Access: | https://hal.science/hal-01332757 https://hal.science/hal-01332757/document https://hal.science/hal-01332757/file/2016GL067821.pdf https://doi.org/10.1002/2016GL067821 |
Summary: | International audience More than 10 years of geodetic measurements demonstrate an uplift rate of 1–3 mm/yr of the high topography region of the Western Alps. By contrast, no significant horizontal motion has been detected. Two uplift mechanisms have been proposed: (1) the isostatic response to denudation responsible for only a fraction of the observed uplift and (2) the rebound induced by the Wurmian ice cap melting which predicts a broader uplifting region than the one evidenced by geodetic observations. Using a numerical model to fit the geodetic data, we show that a crustal viscosity contrast between the foreland and the central part of the Alps, the latter being weaker with a viscosity of 1021 Pa s, is needed. The vertical rates are enhanced if the strong uppermost mantle beneath the Moho is interrupted across the Alps, therefore allowing a weak vertical rheological anomaly over the entire lithosphere. |
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