Observed crustal uplift near the Southern Patagonian Icefield constrains improved viscoelastic Earth models. Issue 3 (5th February 2014)

• Record Type: Journal Article
• Authors: Lange, H.; Casassa, G.; Ivins, E. R.; Schröder, L.; Fritsche, M.; Richter, A.; Groh, A.; Dietrich, R.
• Is Part Of: Geophysical research letters. Volume 41:Issue 3(2014:Feb.)
• Page Start: 805
• Page End: 812
• Publication Date: 2014-02-05
• Subjects: Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2013GL058419
• Languages: English
• ISSNs: 0094-8276

Abstract

<abstract abstract-type="main" id="grl51319-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p id="grl51319-para-0001">Thirty‒one GPS geodetic measurements of crustal uplift in southernmost South America determined extraordinarily high trend rates (&gt; 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 <italic>η</italic> =1.6 ×10¹⁸ 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: <italic>η</italic> = 8.0 ×10¹⁸ 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.</p> </abstract>