Observed crustal uplift near the Southern Patagonian Icefield constrains improved viscoelastic Earth model

Thirty‒one GPS geodetic measurements of crustal uplift in southernmost South America determined extraordinarily high trend rates (> 35 mm/yr) in the north‒central part of the Southern Patagonian Icefield. These trends have a coherent pattern, motivating a refined viscoelastic glacial isostatic ad...

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Autores principales: Lange, H., Casassa, G., Ivins, E. R., Schröder, L., Fritsche, M., Richter, Andreas Jorg, Groh, A., Dietrich, R.
Formato: Articulo
Lenguaje:Inglés
Publicado: 2014
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Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/102564
https://ri.conicet.gov.ar/11336/31153
http://onlinelibrary.wiley.com/doi/10.1002/2013GL058419/abstract
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Sumario:Thirty‒one GPS geodetic measurements of crustal uplift in southernmost South America determined extraordinarily high trend rates (> 35 mm/yr) in the north‒central part of the Southern Patagonian Icefield. These trends have a coherent pattern, motivating a refined viscoelastic glacial isostatic adjustment model to explain the observations. Two end‒member models provide good fits: both require a lithospheric thickness of 36.5 ± 5.3 km. However, one end‒member has a mantle viscosity near η =1.6 ×10<sup>18</sup> Pa s and an ice collapse rate from the Little Ice Age (LIA) maximum comparable to a lowest recent estimate of 1995–2012 ice loss at about −11 Gt/yr. In contrast, the other end‒member has much larger viscosity: η = 8.0 ×10<sup>18</sup> Pa s, half the post–LIA collapse rate, and a steadily rising loss rate in the twentieth century after AD 1943, reaching −25.9 Gt/yr during 1995–2012.