Retreat of Humboldt Gletscher, North Greenland, Driven by Undercutting From a Warmer Ocean.

Autor: Rignot E; Department Earth System Science University of California Irvine Irvine CA USA.; Jet Propulsion Laboratory California Institute of Technology Pasadena CA USA., An L; Department Earth System Science University of California Irvine Irvine CA USA., Chauche N; Access Arctic SARL Le Vieux Marigny France., Morlighem M; Department Earth System Science University of California Irvine Irvine CA USA., Jeong S; Department Earth System Science University of California Irvine Irvine CA USA., Wood M; Department Earth System Science University of California Irvine Irvine CA USA.; Jet Propulsion Laboratory California Institute of Technology Pasadena CA USA., Mouginot J; Department Earth System Science University of California Irvine Irvine CA USA.; Institut des Geosciences de l'Environnement Universite Grenoble-Alpes CNRS Grenoble France., Willis JK; Jet Propulsion Laboratory California Institute of Technology Pasadena CA USA., Klaucke I; GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany., Weinrebe W; GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany., Muenchow A; School of Marine Science and Policy University of Delaware Newark DE USA.
Jazyk: angličtina
Zdroj: Geophysical research letters [Geophys Res Lett] 2021 Mar 28; Vol. 48 (6), pp. e2020GL091342. Date of Electronic Publication: 2021 Mar 24.
DOI: 10.1029/2020GL091342
Abstrakt: Humboldt Gletscher is a 100-km wide, slow-moving glacier in north Greenland which holds a 19-cm global sea level equivalent. Humboldt has been the fourth largest contributor to sea level rise since 1972 but the cause of its mass loss has not been elucidated. Multi-beam echo sounding data collected in 2019 indicate a seabed 200 m deeper than previously known. Conductivity temperature depth data reveal the presence of warm water of Atlantic origin at 0°C at the glacier front and a warming of the ocean waters by 0.9 ± 0.1°C since 1962. Using an ocean model, we reconstruct grounded ice undercutting by the ocean, combine it with calculated retreat caused by ice thinning to floatation, and are able to fully explain the observed retreat. Two thirds of the retreat are caused by undercutting of grounded ice, which is a physical process not included in most ice sheet models.
(© 2021. The Authors.)
Databáze: MEDLINE
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