Hot rocks add heat to ice sheet models

Incorporating the distribution of 'hot rocks' in East Antarctica into ice sheet models, will improve predictions of ice sheet behaviour and potential sea-level change, according to new Australian research.

Speaking at the 'Strategic Science in Antarctica' conference in June, Dr Chris Carson from Geoscience Australia, said naturally occurring 'heat-producing elements' - mainly uranium, thorium and potassium - present in certain rock types found in Antarctica, contribute to local and regional-scale variation in heat flow underneath the ice sheet. They do this by generating tiny amounts of heat by radioactive decay.

'These regions of elevated heat flow potentially can contribute to ice surging and ice stream flow,' Dr Carson said.

Sub-glacial heat flow under the West Antarctic ice sheet has been measured at a number of sites and found to be elevated due to active rifting and volcanism. However, crustal heat flow beneath the East Antarctic ice sheet is poorly understood, and instead, a broadly uniform heat flow across much of the region is often assumed in ice sheet models. Such assumptions ignore the natural variability of heat flow due to variations in the sub-glacial geology.

To illustrate the scale and importance of this variability, Dr Carson and colleagues from the Australian Antarctic Division, Antarctic Climate and Ecosystems Cooperative Research Centre, University of Melbourne and the University of Texas, recently published a paper in the Journal of the Geological Society, London, describing the distribution of hot rocks, and their impact on regional heat flow, in different parts of the Australian Antarctic Territory.

In a 275 km transect along the Prydz Bay coastline - running from the Vestfold Hills to the Amery Ice Shelf - heat production values for individual rock types (derived from geochemical analysis of the rocks) ranged from 0.02 µW per cubic metre to almost 66 µW per cubic metre (1 µW [micro Watt] is 0.000001 Watts).

'There is generally low and reasonably typical heat production in rocks of the northern Prydz Bay region - in the Vestfold Hills and Rauer Group,' Dr Carson said.

'However, in southern Prydz Bay, there are numerous outcrops of Cambrian-aged granites which are characterised by elevated heat production. The presence of these hot rocks fundamentally affects the regional heat flow in southern Prydz Bay.'

Available aeromagnetic data suggests that these hot granites may be more widespread underneath the ice sheet in southern Prydz Bay.

Dr Carson said a better knowledge of the sub-glacial location and distribution of such granites across East Antarctica is essential for understanding regional heat flow characteristics of the Antarctic crust. This information can then be factored into ice modelling studies.

`The assumption that the crust of East Antarctica is thermally homogenous is inappropriate and it is critical that both local and regional geology are considered in ice modelling studies,- he said.

'As elevated and variable heat flow would have a fundamental effect on ice sheet behaviour, incorporating geological controls on heat flow into models could refine predictions of ice mass balance and sea-level change.'

Simple

Identification info

Date (Publication)
2013-01-01T00:00:00
Citation identifier
Geoscience Australia Persistent Identifier/https://pid.geoscience.gov.au/dataset/ga/77670

Cited responsible party
Role Organisation / Individual Name Details
Publisher

Australian Antarctic Division

 Australian Antarctic Division, Channel HWY Kingston TAS 7050
Author

Carson, C.J.

 1
Name

Australian Antarctic Magazine

ISBN

14451735

Point of contact
Role Organisation / Individual Name Details
Point of contact

Commonwealth of Australia (Geoscience Australia)

 Voice
Resource provider

Place and Communities Division

 External Contact
Point of contact

McLennan, S.

 Place and Communities Internal Contact
Topic category
  • Geoscientific information

Extent

N
S
E
W


Maintenance and update frequency
As needed
Keywords

  • Educational Product

  • Other

Theme

  • Educational Product

  • antarctica

  • geothermal

  • marine

Australian and New Zealand Standard Research Classification (ANZSRC)

  • Earth Sciences

Keywords

  • Published_External

Resource constraints

Title

Creative Commons Attribution 4.0 International Licence

Alternate title

CC-BY

Edition

4.0

Website

http://creativecommons.org/licenses/

Access constraints
License
Use constraints
License

Resource constraints

Title

Australian Government Security ClassificationSystem

Edition date
2018-11-01T00:00:00
Website

https://www.protectivesecurity.gov.au/Pages/default.aspx

Classification
Unclassified
Language
English
Character encoding
UTF8

Distribution Information

Distributor contact
Role Organisation / Individual Name Details
Distributor

Commonwealth of Australia (Geoscience Australia)

 Voice
OnLine resource

Related product: Crustal Heat Production in the Australian Antarctic Territory

Related product: Crustal Heat Production in the Australian Antarctic Territory

OnLine resource

Link to article

Link to article

OnLine resource

Related product: Hot rocks in a cold place: high sub-glacial heat flow in east Antarctica

Related product: Hot rocks in a cold place: high sub-glacial heat flow in east Antarctica

OnLine resource

Related product: A reconnaissance crustal heat production assessment of the Australian Antarctic Territory (AAT)

Related product: A reconnaissance crustal heat production assessment of the Australian Antarctic Territory (AAT)

Resource lineage

Statement

Unknown

Hierarchy level
Non geographic dataset
Other

Educational Product

Description

Source data not available.

Metadata constraints

Title

Australian Government Security ClassificationSystem

Edition date
2018-11-01T00:00:00
Website

https://www.protectivesecurity.gov.au/Pages/default.aspx

Classification
Unclassified

Metadata

Metadata identifier
urn:uuid/e73c50af-fc44-47ac-e044-00144fdd4fa6

Title

GeoNetwork UUID

Language
English
Character encoding
UTF8
Contact
Role Organisation / Individual Name Details
Point of contact

Commonwealth of Australia (Geoscience Australia)

 Voice
Point of contact

McLennan, S.

 Place and Communities Internal Contact

Type of resource

Resource scope
Document
Name

nonGeographicDataset

Alternative metadata reference

Title

Geoscience Australia - short identifier for metadata record with

uuid

Citation identifier
eCatId/77670

Metadata linkage

https://ecat.ga.gov.au/geonetwork/srv/eng/catalog.search#/metadata/e73c50af-fc44-47ac-e044-00144fdd4fa6

Date info (Revision)
2018-04-22T08:43:12
Date info (Creation)
2013-09-26T00:00:00

Metadata standard

Title

AU/NZS ISO 19115-1:2014

Metadata standard

Title

ISO 19115-1:2014

Metadata standard

Title

ISO 19115-3

Title

Geoscience Australia Community Metadata Profile of ISO 19115-1:2014

Edition

Version 2.0, September 2018

Citation identifier
https://pid.geoscience.gov.au/dataset/ga/122551

 
 

Spatial extent

N
S
E
W


Keywords

Educational Product antarctica geothermal marine

Provided by

Access to the portal

Associated resources

Not available