Kinematic response of ice-rise divides to changes in ocean and atmosphere forcing

Schannwell, Clemens; Drews, Reinhard; Ehlers, Todd A.; Eisen, Olaf; Mayer, Christoph; Gillet-Chaulet, Fabien

Publikationsdienste
→
TOBIAS-portale
→
Dokumente aus Instituten und Partnereinrichtungen
→
Copernicus
→
Dokumentanzeige

dc.contributor.author	Schannwell, Clemens
dc.contributor.author	Drews, Reinhard
dc.contributor.author	Ehlers, Todd A.
dc.contributor.author	Eisen, Olaf
dc.contributor.author	Mayer, Christoph
dc.contributor.author	Gillet-Chaulet, Fabien
dc.date.accessioned	2019-10-14
dc.date.accessioned	2019-10-31T12:51:04Z
dc.date.available	2019-10-31T12:51:04Z
dc.identifier	10.5194/tc-13-2673-2019
dc.identifier	https://www.the-cryosphere.net/13/2673/2019/
dc.identifier.uri	http://hdl.handle.net/10900/94103
dc.identifier.uri	http://dx.doi.org/10.15496/publikation-35487
dc.description	<p>The majority of Antarctic ice shelves are bounded by grounded ice rises. These ice rises exhibit local flow fields that partially oppose the flow of the surrounding ice shelves. Formation of ice rises is accompanied by a characteristic upward-arching internal stratigraphy (“Raymond arches”), whose geometry can be analysed to infer information about past ice-sheet changes in areas where other archives such as rock outcrops are missing. Here we present an improved modelling framework to study ice-rise evolution using a satellite-velocity calibrated, isothermal, and isotropic 3-D full-Stokes model including grounding-line dynamics at the required mesh resolution (<span class="inline-formula"><</span>500 m). This overcomes limitations of previous studies where ice-rise modelling has been restricted to 2-D and excluded the coupling between the ice shelf and ice rise. We apply the model to the Ekström Ice Shelf, Antarctica, containing two ice rises. Our simulations investigate the effect of surface mass balance and ocean perturbations onto ice-rise divide position and interpret possible resulting unique Raymond arch geometries. Our results show that changes in the surface mass balance result in immediate and sustained divide migration (<span class="inline-formula">>2.0</span> m yr<span class="inline-formula"><sup>−1</sup></span>) of up to 3.5 km. In contrast, instantaneous ice-shelf disintegration causes a short-lived and delayed (by 60–100 years) response of smaller magnitude (<span class="inline-formula"><0.75</span> m yr<span class="inline-formula"><sup>−1</sup></span>). The model tracks migration of a triple junction and synchronous ice-divide migration in both ice rises with similar magnitude but differing rates. The model is suitable for glacial/interglacial simulations on the catchment scale, providing the next step forward to unravel the ice-dynamic history stored in ice rises all around Antarctica.</p>
dc.format	application/pdf
dc.language	eng
dc.source	eISSN: 1994-0424
dc.title	Kinematic response of ice-rise divides to changes in ocean and atmosphere forcing
dc.type	Text