Expressions of Intent for International Polar Year 2007-2008 Activities

Expression of Interest Details

PROPOSAL INFORMATION

Collaborative Research into Antarctic Calving and tabular iceberg processes  (CRAC)

Outline
CRAC will be a coordinated investigation into iceberg calving processes on Antarctica’s major ice shelves, and a study of the physical processes related to iceberg drift and evolution post-calving. CRAC’s first objective is to develop an understanding of the mechanics of rift initiation and propagation via three complementary components: 1. Fieldwork: Networks of GPS/seismometers and automatic observation stations equipped with web cams will be deployed around selected active rift tips on each ice shelf for an entire year. This will provide the first ever information about rift propagation over winter. These mirror campaigns will provide a continuous time series of rift widening (GPS) as well as rupture locations and source mechanisms (seismic). Ground penetrating radar profiles will be collected, to probe the subsurface structure of the rift. Cores will be taken of the melange for each rift in order to determine its composition. 2. Satellite data analysis: Satellite images (e.g. MODIS, MISR, ASTER, RADARSAT) provide “snapshot” observations of the surface expression of the rift at discrete time intervals. Image pairs provide estimates of velocity, ice strain rates, and rift widening rates. ICESat/CRYOSAT laser and radar altimeter data will be used to provide surface profile information for each rift and estimate thickness of the melange (i.e. ice debris) inside the rifts 3. Modelling: Both physical modelling using laboratory experiments and numerical modelling will be undertaken. Physical modelling, using a large ice tank, will be used to simulate ice shelf behaviour over a range of conditions. The results from these experiments, along with data collected in (1) and (2), will be used to construct realistic numerical models of fracture processes and including the effect of melange within rifts. CRAC’s second objective is a study of the icebergs after calving, using in situ automated observation stations, satellite data, and cruises of opportunity near drifting bergs. Iceberg drift is poorly understood; it is influenced by a combination of tides, currents, wind, and sea ice. Movement of icebergs into lower latitudes emulates the effects of rapid climate change on large ice shelves. Monitoring the evolution of firn, the influence of melt, and the eventual break-up of icebergs will provide insight into how shelves will respond under future warming conditions. Icebergs can also have profound effects on local climate and wind flow, and broad-scale ocean salinity and circulation.

What significant advance(s) in relation to the IPY themes and targets can be anticipated from this project?
1: present environmental status of the polar regions CRAC will provide insight into the stability of the three largest Antarctic ice shelves. 2: to understand change and improve predictions Iceberg calving accounts for much of Antarctica’s mass loss. With better knowledge of this process, we can better predict how ice shelves will evolve in response to a changing climate. 3: Polar-global linkages CRAC will contribute to our knowledge of freshwater fluxes to the ocean and influence on thermohaline circulation, as well as frequency of calving events and ice shelf thinning and their possible impact on ice discharge, and thus on Sea Level Rise. 4: Investigating new frontiers CRAC investigates rifting, calving and iceberg melt, which are all are emerging as important but poorly understood processes.

What international collaboration is involved in this project?
CRAC researchers come together from five countries: USA, UK, Australia, Germany and France. This international collaboration is a new team that builds on existing working relationships and creates new ones. We welcome other collaborators who address similar objectives.

FIELD ACTIVITY DETAILS

Geographical location(s) for the proposed field activities:
Amery Ice Shelf, East Antarctica Ross Ice Shelf, West Antarctica Filchner-Ronne Ice Shelf, West Antarctica Icebergs in selected areas, primarily in Weddell and Ross Seas, and Prydz Bay

Approximate timeframe(s) for proposed field activities:
Arctic: n/a
Antarctic: 03/07 – 03/09            

Significant facilities will be required for this project:
Helicopter and fixed-wing transport aircraft support will be required to deploy and revisit instrumentation at the ice shelf rift tips and icebergs. Ice strengthened research ships will be needed for oceanographic surveys around icebergs and near ice shelf fronts. We will also require ice drilling capability and snow terrain vehicles.

Will the project leave a legacy of infrastructure?
No permanent infrastructure will be left since the rift network stations will be removed after the surveys. A suite of observation stations will be available for follow-up projects, post IPY.

How is it envisaged that the required logistic support will be secured?
Consortium
Own national polar operator
Another national polar operator
National agency

Logistics for Amery Ice Shelf will come from AAD, for Ross Ice Shelf from NSF/NASA and for Filchner-Ronne TBD.

Has the project been "endorsed" at a national or international level?
This Expression of Interest is in the process of being considered by the US National Committee for IPY. It will also be considered by the National Committees of the UK, Australia, Germany and France.

PROJECT MANAGEMENT AND STRUCTURE

Is the project a short-term expansion (over the IPY 2007-2008 timeframe) of an existing plan, programme or initiative or is it a new autonomous proposal?
Exp

CRAC is a new initiative for coordinating research into Antarctic calving on different ice shelves. Separate efforts have taken place previously on individual ice shelves, but we believe that the multiple ice shelf, year-round study will significantly advance our limited understanding of the calving process, and the behaviour of icebergs.

How will the project be organised and managed?
CRAC will be structured so that there are three regional managers (one for each ice shelf) who will be involved in the organisation and management of the whole project. This team of three people will work together to oversee the collection of satellite and field data for each ice shelf, and also coordinate the modelling studies, and the iceberg investigations for that region. The management team will meet regularly via teleconference and email, and at least once per year during international meetings.

What are the initial plans of the project for addressing the education, outreach and communication issues outlined in the Framework document?
CRAC is an ideal project for EOC, since iceberg calving appeals to the general public and media. We will develop teaching tools (websites, movies, presentations) and host school groups to learn about CRAC. We will report major findings to our Communications Offices and National Committees for press releases.

What are the initial plans of the project to address data management issues (as outlined in the Framework document?
CRAC’s regional managers will be responsible for the management of the field data collected on each ice shelf and its icebergs. Remote-sensing data will be managed by one person for each sensor. All data collected as part of CRAC will be stored at both NSIDC and the Australian Antarctic Division.

How is it proposed to fund the project?
For each region, the regional manager will seek logistical support funding from their own national funding agency. For Amery HF and RC will seek logistical support from AAD and financial support from USA (NSF) and Australian (ARC, AAS) funding agencies.

Is there additional information you wish to provide?
Additional project members: 7. Eric Rignot, Jet Propulsion Laboratory, USA 8. Neal Young, Antarctic Climate & Ecosystems CRC and Australian Antarctic Division (AAD), AUS 9. Roland Warner, Antarctic Climate & Ecosystems CRC and Australian Antarctic Division, AUS 10. Benoit Legresy, CNRS, FRA 11. Bernard Minster, Scripps Institution of Oceanography, USA CRAC addresses objectives outlines within CASO (Climate in Antarctica and the Southern Ocean). CRAC is also closely linked to SOIC (Southern Ocean Iceberg Census).

PROPOSER DETAILS

Dr Helen Amanda Fricker
Scripps Institution of Oceanography
9500 Gilman Drive
La Jolla, CA
92093-0225
USA

Tel: 858-534-6156
Mobile: 619-993-3569
Fax: 858-534-2902
Email:

Other project members and their affiliation