Meltwater flow through a rapidly deglaciating glacier and foreland catchment system, Virkísjökull, SE Iceland

TY - CONF

T1 - Meltwater flow through a rapidly deglaciating glacier and foreland catchment system, Virkísjökull, SE Iceland

AU - Flett, Verity

AU - Maurice, Louise

AU - Black, Andrew

AU - MacDonald, Alan

AU - Everest, Jez

AU - Kirkbride, Martin

AU - Finlayson, Andrew

N1 - Presented at session: Glacier catchment hydrology

PY - 2015/6/22

Y1 - 2015/6/22

N2 - This study characterizes the glacial and proglacial hydrology of a rapidly deglaciating system at Virkísjökull in SE Iceland, to determine the water flux through the glacier and proglacial area. This was achieved using dye tracer tests, river discharge measurements and studies of conduits within the foreland and glacier using ground-penetrating radar (GPR). Tracer testing through the glacial system via a moulin demonstrated rapid flow of 0.58 m s–1, which was comparable to the flow rates within the proglacial river, and is at the higher end of velocities observed in glacial conduits. A subsequent test from this moulin at the end of the winter season demonstrated that the conduit system was fully open at this time, suggesting that it may not close during the winter. A tracer test through the proglacial foreland showed that the large proglacial lake does not substantially attenuate flow and revealed the presence of a relic conduit system enabling rapid water transit through this area, with velocities of 0.03 m s–1. The proglacial river is highly responsive to melt as a result of fully developed conduits in both the subglacial and proglacial areas. Given that in the proglacial foreland there are the remains of the previous margin of the glacier, these conduits may be a relic of a previous subglacial pathway that has been abandoned in the foreland. The existence of relic conduits may appear in other deglaciating ice-cored forelands and can have a significant impact on the hydrological connectivity and therefore modelling of river discharge in similar catchments.

AB - This study characterizes the glacial and proglacial hydrology of a rapidly deglaciating system at Virkísjökull in SE Iceland, to determine the water flux through the glacier and proglacial area. This was achieved using dye tracer tests, river discharge measurements and studies of conduits within the foreland and glacier using ground-penetrating radar (GPR). Tracer testing through the glacial system via a moulin demonstrated rapid flow of 0.58 m s–1, which was comparable to the flow rates within the proglacial river, and is at the higher end of velocities observed in glacial conduits. A subsequent test from this moulin at the end of the winter season demonstrated that the conduit system was fully open at this time, suggesting that it may not close during the winter. A tracer test through the proglacial foreland showed that the large proglacial lake does not substantially attenuate flow and revealed the presence of a relic conduit system enabling rapid water transit through this area, with velocities of 0.03 m s–1. The proglacial river is highly responsive to melt as a result of fully developed conduits in both the subglacial and proglacial areas. Given that in the proglacial foreland there are the remains of the previous margin of the glacier, these conduits may be a relic of a previous subglacial pathway that has been abandoned in the foreland. The existence of relic conduits may appear in other deglaciating ice-cored forelands and can have a significant impact on the hydrological connectivity and therefore modelling of river discharge in similar catchments.

UR - https://www.igsoc.org/symposia/2015/iceland/proceedings/procsfiles/procabstracts_67.html#A1669

UR - https://www.igsoc.org/symposia/2015/iceland/proceedings/fullprogramme.html

M3 - Abstract

T2 - International Symposium on Hydrology of Glaciers and Ice Sheets

Y2 - 21 June 2015 through 26 June 2015

ER -