TY - JOUR

T1 - Redefinition of the Amery Ice Shelf, East Antarctica, grounding zone

AU - Fricker, Helen Amanda

AU - Allison, Ian

AU - Craven, Mike

AU - Hyland, Glenn

AU - Ruddell, Andrew

AU - Young, Neal

AU - Coleman, Richard

AU - King, Matt

AU - Krebs, Kim

AU - Popov, Sergey

PY - 2002/5/10

Y1 - 2002/5/10

N2 - New evidence is presented which shows that the Amery Ice Shelf, East Antarctica, extends ∼240 km upstream of the previously reported position. We combine a digital elevation model of the Amery Ice Shelf created from ERS-1 satellite radar altimetry with measured ice thicknesses and a simple density model in a hydrostatic (buoyancy) calculation to map the extent of the floating ice. This reveals that the ice is floating as far south as 73.2°S. The result is confirmed by static GPS measurements collected during three consecutive field campaigns on the Amery Ice Shelf where the vertical component of the GPS shows a clear tidal signal at 72.98°S. Other evidence for the grounding zone position comes from an analysis of satellite imagery, mass flux calculations, and ice radar data. The southward extension of the grounding line substantially alters the shape and dimensions of the ocean cavity beneath the ice shelf, which has implications for modeling studies of sub-ice shelf processes, such as basal melting and freezing, ocean circulation, and tides. The new grounding line position will also improve geophysical studies, where the computation of ocean tidal loading corrections is important for postglacial rebound estimates and correction of satellite altimetry measurements within the region.

AB - New evidence is presented which shows that the Amery Ice Shelf, East Antarctica, extends ∼240 km upstream of the previously reported position. We combine a digital elevation model of the Amery Ice Shelf created from ERS-1 satellite radar altimetry with measured ice thicknesses and a simple density model in a hydrostatic (buoyancy) calculation to map the extent of the floating ice. This reveals that the ice is floating as far south as 73.2°S. The result is confirmed by static GPS measurements collected during three consecutive field campaigns on the Amery Ice Shelf where the vertical component of the GPS shows a clear tidal signal at 72.98°S. Other evidence for the grounding zone position comes from an analysis of satellite imagery, mass flux calculations, and ice radar data. The southward extension of the grounding line substantially alters the shape and dimensions of the ocean cavity beneath the ice shelf, which has implications for modeling studies of sub-ice shelf processes, such as basal melting and freezing, ocean circulation, and tides. The new grounding line position will also improve geophysical studies, where the computation of ocean tidal loading corrections is important for postglacial rebound estimates and correction of satellite altimetry measurements within the region.

KW - Antarctica

KW - Glaciology

KW - Grounding zone

KW - Ice shelf

KW - Radar altimetry

KW - Radio-echo sounding

UR - http://www.scopus.com/inward/record.url?scp=17344383614&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:17344383614

VL - 107

JO - Journal of Geophysical Research: Solid Earth

JF - Journal of Geophysical Research: Solid Earth

SN - 2169-9313

IS - 5

ER -