Expressions of Intent for IPY 2007-2008 Activities

Expression of Interest Details

PROPOSAL INFORMATION

The Enderby Basin and the Bay of Bengal, missing links of the circum Antarctic Plate Tectonics between 160 and 80 Ma  (Circum Antarctic Plate Tectonics in the Indian OceaN (CAPTION))

Outline
If the history of the lithospheric plates that constitute the surface of our planet is quite well known for the last 160 millions years (Ma), the present models still include some very simplifying assumptions as far as the poorly surveyed Austral Ocean is concerned. One of the major difficulties of these models is the evolution of the plate boundary which separates Antarctica from India during the initial dispersal of Gondwanaland from ~160 to ~80 Ma. The area of interest includes the present Enderby Basin and Bay of Bengal. We propose to investigate these areas as part of an international cooperation including French, Japanese and Indian researchers. The proposed research would start with a joint analysis of the existing geophysical data and continue through the acquisition of new data in the Enderby Basin.In a first stage, the available bathymetric, gravity and magnetic data will be gathered in a common data base. Many Japanese and some French profiles have been collected in the Enderby Basin, whereas a large amount of Indian data is available in the Bay of Bengal. Free-air gravity anomaly maps deduced from dense satellite altimetry data will help the interpretation where the marine geophysical profiles are sparse. The data from both basins will be jointly interpreted, i.e. the Enderby Basin and Bay of Bengal will be reconstructed to their well-constrained past position at ~80 Ma (magnetic anomaly 33) and the data will be analyzed in order to build a consistent model for the previous evolution of these basins. Unlike models proposed in previous studies based on limited data sets, this model will satisfy the data from both basins. Such a preliminary analysis should be carried out in 2005-2006 through visits and joint work among the project participants.In the Enderby Basin, the new model will rely on relatively sparse data, mostly acquired during transits to Antarctica bases. Parts of the model will require confirmation and/or refinement through the acquisition of new geophysical data along carefully defined routed in key areas. We propose the acquisition of these new data to be carried out as part of the International Polar Year in 2007-2008. This acquisition could be achieved by diverting French R/V Marion Dufresne, eventually during a rotation to the French sub-Antarctic Islands, or the Japanese and Indian research vessels supplying Syowa and Maitri Antarctic bases. A final phase of data processing and interpretation and reassessment of the model should be carried out in 2008-2009 by the project participants.

What significant advance(s) in relation to the IPY themes and targets can be anticipated from this project?
We expect to (1) decipher the plate tectonic evolution of the Antarctica-India plate boundary between 80 and 160 Ma; (2) improve significantly our knowledge on the structure and age of the Enderby Basin (and Bay of Bengal); (3) determine the nature and age of various oceanic plateaus within or at the boundaries of the Enderby Basin, i.e. Gunnerus Ridge, Conrad Rise, Elan Bank, Crozet Plateau, Kerguelen Plateau...; and (4) constrain the age of the Antarctic margins and the initial spreading direction at this margin. An obvious consequence will be a better global plate tectonics model for the last 200 Ma. Because it aims “to investigate the unknowns at the frontiers of science in the polar regions”, the project is clearly relevant to Theme 4, although it may also help to better define geological environment of Antarctica (Theme 1) and its changes through geologic times (Theme 2).

What international collaboration is involved in this project?
The project strongly relies on a collaborative approach involving the exchange of data from national databases and the joint acquisition of complementary data. Researchers from French, Japanese, and Indian institutions are involved in the project. Contacts are underway for researchers from an Australian Institute to possibly join the project.

FIELD ACTIVITY DETAILS

Geographical location(s) for the proposed field activities:
The area for the marine operations is the Enderby Basin, off Antarctica between 30 and 80°E. The project will take advantage of scientific ships supplying the Antarctic and sub-Antarctic bases, for instance R/V Marion Dufresne for the French sub-Antarctic Islands. Exact location of the geophysical profiles cannot be indicated before the first stage of the project is completed (see above). If the required profiles are far from each other, they could be scheduled onboard different ships of opportunity during transits.

Approximate timeframe(s) for proposed field activities:
Arctic: Austral summer (i.e. November 2007-March 2008) is the adequate time window to acquire marine geophysical data in circum-Antarctic regions.            
Antarctic: n/a

Significant facilities will be required for this project:
Research vessel(s) with multibeam echo sounder, gravimeter, shipboard and surface towed magnetometers, as well as “light” reflection seismic equipment operated at a relatively high speed, would be optimal for the planned operations. Considering the extension of the Enderby Basin and the possibility of distant profiles for each others, the possibility to use different ships of opportunity during transits to or from Antarctic or sub-Antarctic bases should be seriously considered. Of course the ship(s) can be shared with other projects.

Will the project leave a legacy of infrastructure?

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

Either national polar operators (IPEV, NIPR, NCAOR) or national marine research agencies (IFREMER, JAMSTEC, NIO) can carry out parts of the proposed sea operations. Although they may interact as a “consortium”, no joint logistic is required for the project.

Has the project been "endorsed" at a national or international level?
The project has been endorsed by the French Committee for the IPY

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
The project is a new project which results from discussions during visits and scientific meetings. Indo-French collaboration in marine geophysics and plate tectonics has been active for about 5 years between the National Institute of Oceanography, Goa, Université de Bretagne Occidentale, Brest and Institut de Physique du Globe, Paris, within the framework of two projects funded by the Indo-French Center for the Promotion of Advanced Research. Informal collaborations between French and Japanese proponents exist for about 8 years and involve crossed participations to cruises, exchange of students and instruments, and joint research on mid-ocean ridges.

How will the project be organised and managed?
The project involves a small number of participants in three countries and does not require an important management structure. In each country a Principal Investigator (PI) will take care of the relationships with the national IPY committee, the national polar operator, and other national agencies. The financial matters will be managed at national level under his responsibility. Initially each PI will have to obtain the support of the national IPY committee to the project, and then use this support to secure funding for the first phase, data compilation and joint analysis. The accomplishment of this first phase will help to achieve a closer integration of the scientific team, required to prepare for the second phase, i.e. deciding the targets for sea-going operations and the best strategy to hit these targets (one dedicated cruise versus transit valorisations on one or several ships…). The PIs will implement this strategy by submitted applications at national level for ship time and/or financial support to participate to the cruise. The sea operation and subsequent processing and interpretation, jointly led by the PIs, will involve all interested participants.

What are the initial plans of the project for addressing the education, outreach and communication issues outlined in the Framework document?
During the first phase of the project, the only specific action envisioned is the creation of a Web site which would show progress of the project, discuss the interpretation of marine geophysical data, and present the various plate kinematics models though animated movies. The second phase is more adequate for communication, education and outreach: the ship permitting, we may even welcome a journalist or a school teacher who would be in charge to report daily about the cruise and communicate with the public and/or selected schools.

What are the initial plans of the project to address data management issues (as outlined in the Framework document)?
The relevant data available to project participants in France, Japan, and India, will be compiled in a common format and made available to all other project participants. Due to specific institutional policies regarding data dissemination, data will only be provided to third parties with the express consent of the initial data provider. However, an effort will be made to insure the widest possible dissemination of these data at the end of project. Data acquired within the project will be available to all project participants. They will be archived in national and international data centres at the end of the project.

How is it proposed to fund the project?
During the first phase of the project (data compilation and joint analysis), a limited financial support including visits should be obtained at national level (national IPY committees, polar institutes, other research funding agencies). The second phase (acquisition of new data in the Enderby Basin) will be submitted through usual channels for sea-going expeditions and would therefore be mostly funded at national level, although a financial contribution from the IPY committees of the participating countries may help to insure the availability of the ship(s) during the austral summer 2007-2008. The third phase (processing and interpretation of the new data) again requires a quite limited financial support, to be obtained at national level.

Is there additional information you wish to provide?
The proposed project has been “in the air” for some time but was lacking a proper framework to be accepted as part of a programme by the institutions in each countries. Such acceptance is necessary to proceed with exchange of data and expertise, week or month-long international work visits, or even joint proposals for cruise or transit valorisation. The International Polar Year offers a unique opportunity to realize this investigation long-awaited by global Plate Tectonics. Conversely, the project will provide IPY a better understanding of the place of Antarctica in the early dispersal of Gondwanaland. The structure, age and evolution of the Enderby Basin will be better constrained, with consequences on the sub Antarctic oceanic plateaus and the Antarctic margins.

PROPOSER DETAILS

Dr. Jérôme DYMENT
CNRS-IPGP UMR 7097 “Laboratoire de Géosciences Marines”
Institut de Physique du Globe de Paris
4 place Jussieu, Paris
F-75005
France

Tel: (+33) 1 44 27 28 21
Mobile: (+33) 6 84 18 18 11
Fax: (+33) 1 44 27 99 69
Email:

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