dc.contributor |
Háskóli Íslands |
dc.contributor |
University of Iceland |
dc.contributor.author |
Minchew, Brent |
dc.contributor.author |
Simons, Mark |
dc.contributor.author |
Björnsson, Helgi |
dc.contributor.author |
Pálsson, Finnur |
dc.contributor.author |
Morlighem, Mathieu |
dc.contributor.author |
Seroussi, Helene |
dc.contributor.author |
Larour, Eric |
dc.contributor.author |
Hensley, Scott |
dc.date.accessioned |
2017-09-20T14:25:34Z |
dc.date.available |
2017-09-20T14:25:34Z |
dc.date.issued |
2016-02 |
dc.identifier.citation |
MINCHEW, B., SIMONS, M., BJÖRNSSON, H., PÁLSSON, F., MORLIGHEM, M., SEROUSSI, H., . . . HENSLEY, S. (2016). Plastic bed beneath Hofsjökull Ice Cap, central Iceland, and the sensitivity of ice flow to surface meltwater flux. Journal of Glaciology, 62(231), 147-158. doi:10.1017/jog.2016.26 |
dc.identifier.issn |
0022-1430 |
dc.identifier.issn |
1727-5652 (eISSN) |
dc.identifier.uri |
https://hdl.handle.net/20.500.11815/402 |
dc.description.abstract |
The mechanical properties of glacier beds play a fundamental role in regulating the sensitivity of glaciers to environmental forcing across a wide range of timescales. Glaciers are commonly underlain by deformable till whose mechanical properties and influence on ice flow are not well understood but are critical for reliable projections of future glacier states. Using synoptic-scale observations of glacier motion in different seasons to constrain numerical ice flow models, we study the mechanics of the bed beneath Hofsjökull, a land-terminating ice cap in central Iceland. Our results indicate that the bed deforms plastically and weakens following incipient summertime surface melt. Combining the inferred basal shear traction fields with a Coulomb-plastic bed model, we estimate the spatially distributed effective basal water pressure and show that changes in basal water pressure and glacier accelerations are non-local and non-linear. These results motivate an idealized physical model relating mean basal water pressure and basal slip rate wherein the sensitivity of glacier flow to changes in basal water pressure is inversely related to the ice surface slope. |
dc.description.sponsorship |
This research was conducted at the California Institute of Technology and the University of Iceland with funding provided by the NASA Crysopherice Sciences Program (Award NNX14AH80G). B. M. was partially funded by a NASA Earth and Space Sciences Fellowship and an Achievement Rewards for College Students (ARCS) fellowship. InSAR data are freely available from the Alaska Satellite Facility via the UAVSAR website (http://uavsar.jpl.nasa.gov). |
dc.format.extent |
147-158 |
dc.language.iso |
en |
dc.publisher |
Cambridge University Press (CUP) |
dc.relation.ispartofseries |
Journal of Glaciology;62(231) |
dc.rights |
info:eu-repo/semantics/openAccess |
dc.subject |
Glaciology |
dc.subject |
Surface velocity |
dc.subject |
Basal mechanics |
dc.subject |
Basal plasticity |
dc.subject |
Basal hydrology |
dc.subject |
Jöklafræði |
dc.subject |
Jöklar |
dc.subject |
Basalt |
dc.title |
Plastic bed beneath Hofsjökull Ice Cap, central Iceland, and the sensitivity of ice flow to surface meltwater flux |
dc.type |
info:eu-repo/semantics/article |
dcterms.license |
This is an Open Access article, distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike licence (http://creativecommons.org/licenses/by-nc-sa/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the same Creative Commons licence is included and the original work is properly cited. The written permission of Cambridge University Press must be obtained for commercial re-use. |
dc.description.version |
Peer Reviewed |
dc.identifier.journal |
Journal of Glaciology |
dc.identifier.doi |
10.1017/jog.2016.26 |
dc.relation.url |
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143016000265 |
dc.contributor.department |
Jarðvísindastofnun (HÍ) |
dc.contributor.department |
Institute of Earth Sciences (UI) |
dc.contributor.school |
Verkfræði- og náttúruvísindasvið (HÍ) |
dc.contributor.school |
School of Engineering and Natural Sciences (UI) |