1. Australian Antarctic Data Centre
2. Discover and Manage Data
3. Records
4. AAS_4342_GPR_2016-2017

Description

Ground penetrating radar (GPR) survey of Channel Lake feature on Sorsdal Glacier
Instrument: MALA X3Mc control system
Antennas: MALA Ramac 250 and 800 MHz
Files:
*.zip - Raw radar return
*.xlsx - Notes for each survey line
Schaap_Thesis.pdf - Honours thesis of Tom Schaap containing further details of survey.

Numerical models of outlet glacier dynamics provide indicators for the state of the ice sheets from which they originate. Basement characteristics and englacial meltwater behaviour are important considerations in these models. Seismic, airborne radio-echo sounding, ground-penetrating radar, and gamma-ray spectrometry surveys have been analysed for information which may improve dynamics modelling of Sorsdal Glacier, East Antarctica.
Seismic reflection data indicate that Sorsdal Glacier sits on a retrograde bed, with measured ice thickness above water ranging from 611 plus or minus 28 m towards the calving front to 1045 plus or minus 48 near the grounding line. The maximum measured grounded ice thickness was 1647 plus or minus 77 m. The maximum measured water column thickness was 500 plus or minus 13 m. The grounding line position was constrained to within 4 km between seismic soundings. Refraction and surface wave analyses indicate that there is no near-surface low-velocity firn layer in the lower portion of Sorsdal Glacier.
Two airborne radio-echo sounding profiles have revealed internal stratigraphy and basement topography in the ice sheet adjacent to Sorsdal Glacier, but do not show the base of the glacier likely due to the effects of scattering of radio waves in highly deformed ice.
Ground-penetrating radar surveys in the Channel Lake area delineate subsurface reflective features at depths between 5 and 10 m. There features are interpreted as former englacial drainage conduits beneath the basin and may indicate the presence of an interconnected network of channels.
Heat production values between 1.1 plus or minus 0.4 micro W/m3 and 1.6 plus or minus 0.5 micro W/m3 were estimated using gamma-ray spectrometry for lithologies in the Vestfold Hills adjacent to Sorsdal Glacier. These values are low compared to estimates from other East Antarctic rocks, and global averages.

GPR data are colelcted in a standard GPR format, and can be viewed with the GPRSoft software at the provided URL.

Quality

See the thesis in the download file for more information.

Access

These data are publicly available for download from the provided URL.

Temporal Coverages

• Start date: 2017-02-02 - Stop date: 2017-02-03

Spatial Coverages

Science Keywords

• EARTH SCIENCE > CRYOSPHERE > GLACIERS/ICE SHEETS > GEOMETRY OF INTERNAL REFLECTIONS
• EARTH SCIENCE > CRYOSPHERE > GLACIERS/ICE SHEETS > GLACIER MOTION/ICE SHEET MOTION

Use Constraints

This data set conforms to the CCBY Attribution License (http://creativecommons.org/licenses/by/4.0/).

Please follow instructions listed in the citation reference provided at http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=AAS_4342_GPR_2016-2017 when using these data.