Expressions of Intent for IPY 2007-2008 Activities

Expression of Interest Details

PROPOSAL INFORMATION

A Broadband Seismic Experiment to Image the Lithosphere beneath the Gamburtsev Mountains, East Antarctica  (GAMSEIS)

Outline
The GSM lie near the center of East Antarctica and exhibit some of the highest deglaciated elevations (~2500 m) on the continent. Knowledge about the origin of the GSM is vitally important for addressing several first-order problems. Because the first Cenozoic glaciers probably initiated on the GSM at about 34 Ma, determining how the GSM formed is critical for understanding Earth’s climate and glacial history. Geological inputs to climate-ice sheet models, including paleo-topography and heat flow, are completely unconstrained because the lithospheric structure and geologic history of the GSM and surrounding regions are unknown. Understanding the origin of the GSM is especially critical for constraining the geothermal heat flux that is applied at the base of ice-sheet models.We propose a passive seismic experiment to image the crust and lithosphere beneath the GSM and to test models for the history and structure of the East Antarctic craton. It is commonly assumed that the interior of East Antarctica is a vast Archean craton. However, a recent reinterpretation of the Precambrian geology suggests that East Antarctica is comprised of several Proterozoic orogenic belts surrounding smaller Archean blocks. Given what little is known about the tectonic history of East Antarctica, Cenozoic hotspot volcanism or an older (Mesozoic?) basalt-capped plateau appear to be likely candidates for the origin of the GSM. We propose to deploy approximately 25 broadband seismographs near and atop the GSM with a station spacing of 100-200 km and operate them for two years. Australian stations will be deployed by aircraft operating from Australian bases along the coast, and US stations will be deployed by aircraft or by traverse from the South Pole. Data from this array will yield the first detailed constraints on crustal and upper mantle structure beneath and surrounding the GSM, on the processes which support the high elevation of this region, and on the tectonic framework of the interior of the East Antarctic craton. These constraints, extracted from the seismic data using a number of proven modeling techniques, including body and surface wave tomography, receiver functions, and shear wave splitting, will enable us to discriminate between candidate models for the origin of the GSM, and will provide the foundation for more detailed studies of the East Antarctic interior in the future.

What significant advance(s) in relation to the IPY themes and targets can be anticipated from this project?
The Gamburtsev Seismic Experiment will directly address the IPY themes in the UCSU Framework document:#4: Investigate the Frontiers of Science in the Polar Regions: The Gamburtsev Mountains have only been surveyed by a couple of traverses decades ago and by several flyovers. There are no rock samples or even potential fields or elevation data to evaluate their geological history. They truly represent the geographical frontier of science in Antarctica.#5 … develop and enhance observatories from the interior of the Earth to the Sun…The Gambursev seismic array will provide an observatory for seismic waves in the Antarctic and, in addition to clarifying the geological setting of the GSM, assist in the location of earthquakes throughout the southern hemisphere and provide a unique dataset of seismic waves traversing the inner core along polar paths parallel to the inner core anisotropy axis.

What international collaboration is involved in this project?
Anya Reading and Brian Kennett, The Australian National UniversityThis project will image the deep earth structure of the Gamburtsev Mountains providing key components to The Gamburtsev Mountains: Integrated International Exploration of the Earth’s Most Enigmatic Mountain Range

FIELD ACTIVITY DETAILS

Geographical location(s) for the proposed field activities:
The field area will generally encompass the Gambursev Subglacial Mountains and surrounding regions. Geographically it will extend from 76-85 degrees south latitude and 70-110 degrees east longitude.

Approximate timeframe(s) for proposed field activities:
Arctic: n/a
Antarctic: 11/06 – 01/07      11/07 – 01/08      11/08 – 01/09

Significant facilities will be required for this project:
Stations will be deployed using small fixed wing aircraft (such as twin otter) and in some cases, by overland traverse. A small field camp may be established near the Gamburtsev mountains to facilitate fixed wing operation.

Will the project leave a legacy of infrastructure?
Project will leave several permanently operating seismic stations in the Gamburtsev region in collaboration with POLENET (Terry Wilson, lead). Project will also prototype field operations in the Gambursev region, including establishing fuel caches and a remote field camp location, and either C-130 landing sites or overland traverse routes. Seismic data will be freely available from the IRIS data center and Australian data center after two years and will be the first seismic data available from this region.

How is it envisaged that the required logistic support will be secured?

Has the project been "endorsed" at a national or international level?
Project is under consideration by the US National Science Foundation.The Gamburtsev Mountains were identified in the US IPY Planning Document as an important target for explorationPreliminary notification provided to Australian Authorities

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?
yes
This program is an outgrowth of the SEAP workshop in Boulder Colorado, in March 2003. We anticipate substantial interaction with other solid earth projects proposed for IPY, such as POLENET (lead proponent: Terry Wilson), GAMBIT (lead proponent: Carol Finn), CRYSTAL (lead proponent: Rhett Butler) and the Italian TANGO initiative (lead proponent: Andrea Morelli).

How will the project be organised and managed?
Management decisions will be made by a group of scientists from the US, Australia, and any other country which joins. At the present time, this would be Reading and Kennett from Australia and Nyblade and Wiens from the US. The GAMSEIS program will coordinate with the international Gamburtsev Mountains Exploration effort. Support for the US effort will be provided by the US Antarctic Program and logistics will be coordinated through them. Instrumentation support for the US effort will be obtained through the IRIS-PASSCAL instrument center and technical decisions will be made with their consultation. Australian instrumentation will be obtained from the ANSIR National Research Facility.

What are the initial plans of the project for addressing the education, outreach and communication issues outlined in the Framework document?
We will coordinate E&O outreach activities with the well developed E&O programs of IRIS as well as other E&O programs supported by the US Antarctic Program. Some specific ideas include engaging teachers to utilize data products in the classroom, use of webcams and web blogs to follow the installation expedition, etc.

What are the initial plans of the project to address data management issues (as outlined in the Framework document)?
Data from both the US and Australian components will be freely distributed by the IRIS Data Management Center two years after the completion of the project.

How is it proposed to fund the project?
Project will be funded by each nation’s own scientific organizations. For the US, this will be the Office of Polar Programs in the US National Science Foundation. . For Australia: logistic support will be sought from Australian Antarctic Division and other funding from the Australian Research Council.

Is there additional information you wish to provide?
None

PROPOSER DETAILS

Professor Douglas Wiens
Dept. of Earth and Planetary Sci., Washington University
1 Brookings Drive
St. Louis, MO
63130
USA

Tel: 314-935-6517
Mobile: 314-348-9700
Fax: 314-935-7361
Email:

Other project members and their affiliation

Other Information