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SCAR Bulletin No 134, July 1999

Working Groups on Geology and Solid Earth Geophysics

The SCAR Working Groups on Geology (WG-Geology) and Solid-Earth Geophysics (WG-SEG) met jointly during 21, 23 and 24 July and were joined by Members of the Working Group on Geodesy & Geographic Information on 23 July.

1. 8th International Symposium on Antarctic Earth Sciences (ISAES)

F J Davey indicated that preparations for 8th ISAES, to be held at Victoria University, Wellington, New Zealand, 5-9 July 1999, are well-advanced. The second (and last) circular is being printed and will be distributed shortly. The scientific sessions will be categorized in topics within geological time slices to reflect the development and evolution of the Antarctic continent. Posters are expected to be on display for 2 days each. Abstract deadline is set for 1 March 1999, and the registration fee of NZ$500 is due to be paid by 31 March 1999. A full programme of field excursions, to demonstrate several classic areas of New Zealand geology, is being prepared and will be scheduled prior to, during and after the symposium.

2. 9th ISAES

A formal invitation to hold the 9th ISAES in Potsdam, Germany, in 2003 had been received. Details of the proposal were presented by H Miller on behalf of the German National Committee for SCAR. The meeting is planned to take place at a new conference centre now being constructed in Albert-Einstein-Park (the former Telegraphenberg) in late August or early September. A novel departure was to frame topics that would bring in members of both the geodetic and glaciological communities. The invitation was accepted unanimously.

3. EUG, Strasbourg, May 1999

R Schlich informed members that the coming biennial EUG (European Union of Geoscience) meeting, which now attracts some 3000 participants from all over the world, is being coordinated by Sweden. A session on polar geoscience has elicited a good response for topics from the Arctic community but not from the Antarctic community. Although time is short, suggestions should be put forward before the end of August.

4. ADMAP

A presentation of recent and future activities of ADMAP (Antarctic Digital Magnetic Anomaly Program) was given by A Meloni (see item 7 of the Report of the Working Group on Solid-Earth Geophysics).

Attention was drawn to incomplete or poor aeromagnetic coverage in the more remote areas of Antarctica. However, given the reluctance of any funding agency to support regional surveys of any kind, strong scientific reasons for completing the work would be needed. Given that there is a major data void over Lake Vostok and the area of the Gamburtsev sub-glacial mountains, it was felt that a strong case should not be difficult to make.

5. ADGRAV

R Bell made a presentation on ADGRAV (Antarctic Digital Gravity Synthesis), (see item 8 of the Report of WG SEG). After some discussion, the ADGRAV initiative was welcomed and endorsed by both Working Groups.

In support of the work, attention was drawn to the value of collecting gravity measurements during traverse of the ITASE project. The joint Working Groups also strongly encouraged the collection of gravity and other geophysical data on all marine surveys, whenever possible.

6. Ocean Drilling Program (ODP)

P Barker reported briefly on the success of the recent ODP Leg 178 to the Antarctic Peninsula margin. Despite concerns of putting to sea with a damaged guide-horn, a range of holes had been drilled in sites on the sediment drifts at the foot of the continental slope, from glacial sediment wedges on the margin, and from the continental shelf itself. The scientific case for a second leg, proposed for Prydz Bay in two years time, was primarily dependent on the acquisition of a suitable picket ship. Plans were also in hand for a third, two-part leg to the Ross Sea and Wilkes Land margin.

7. BEDMAP

Whilst Members were aware of the existence of the BEDMAP project, to prepare a map of the ice-base surface of the Antarctic ice sheet, they urged much closer involvement in the project. The initiative is driven largely by the Working Group on Glaciology but any resultant map should approximate closely to a map of Antarctic bedrock topography and will be of great interest and value to a wide spectrum of the geoscience community.

8. ANTOSTRAT

The need to promote and coordinate efforts to obtain stratigraphical data, relating to the evolution of the Antarctic ice-sheet (through coring and the mounting of seismic surveys), had been identified at XXIV SCAR. The ANTOSTRAT community, charged by SCAR with proposing a way forward, had met last year in Hobart in association with ANTIME to discuss the issue. It had produced an impressive set of papers on scientific results so far and had formulated a proposal for the continuation of ANTOSTRAT initiatives through a sub-committee on Late Phanerozoic [=last 130 million years] glacial history. Members considered that the objectives of the sub-committee should be properly focused, and that its efforts should be clearly distinguished from those of ANTIME whilst ensuring that the two bodies worked closely together. The discussions resulted in a paper, entitled ANTOSTRAT Subcommittee on Late Phanerozoic Glacial History.

The SCAR Working Groups on Geology (WG-Geology) and Solid-Earth Geophysics (WG-SEG) met jointly during 21, 23 and 24 July and were joined by Members of the Working Group on Geodesy & Geographic Information on 23 July

9. Drilling and coring techniques

A short discussion on existing possibilities for the retrieval of rock and sediment samples from beneath the sea and the land surface was held.

Ocean Drilling Program (ODP). Leg 178 to the Antarctic Peninsula margin had been successful; proposals for drilling in the Prydz Bay region now depended largely on the availability of a suitable ice-picket ship; and a cruise to the Ross Sea and Wilkes Land coast had also been tabled.

Following termination of the Cape Roberts Project within the next year or two, the existing rig and supporting camp complex would become available for other projects. The CRP community was anxious that this excellent facility should remain as a resource for the Antarctic geoscience community. However, unless good, well-found science proposals come forward soon, the rig will be sold on commercially so that the CRP consortium may realise its assets. So far, two preliminary proposals are on the table, one to drill the magnetic anomaly inshore of the CRP targets, and a second to drill Quaternary targets in Granite Harbour. However, these are not yet mature and are not funded. Urgent action is required by the community if the facility is to be retained.

Geologists of the British Antarctic Survey and the Spanish Antarctic Programme had collaborated on a drilling and coring programme on the continental shelf of King George Island, the margins of Bransfield Strait, and surroundings of Seymour Island using the BGS (British Geological Survey) vibrocorer/rock drill. Although the drill has a limited capacity (5-6 m), success and recovery were high, with more than 100 rock and coarse-grained sediment cores being obtained in just two weeks. The system requires accurate dynamic positioning of the ship (10% of water depth), but has the advantage of being compact, easily transportable and deployable from a range of research vessels.

A K Cooper gave brief comments on a number of other light-weight drilling systems under development. The portable drill being developed by Norway, with a target capability of 100m below sea-bed, had been tested on two occasions and had been turned over to a commercial company for further development. The Australian 'Gatling gun' type drill was still under development but was understood to be ready for testing soon. RV Gould (US) had been built with a small moon-pool and was capable of deploying a light-weight drill system.

Members also drew attention to the desirability of being able to retrieve cores of the bedrock whenever deep-drilling for ice cores was undertaken. There were reports that sediment had been retrieved from the base of the ice sheet but members were not aware of rock drills being deployed at the base of deep holes.

10. ANTEC - Proposal for a new Group of Specialists

An outline proposal for a new Group of Specialists on Antarctic Neotectonics (ANTEC) had debated at length in separate and joint sessions. The thrust of the proposal is that Antarctica has several unique tectonic characteristics that require investigation by geological, geophysical and geodetic techniques. With the availability of sub-centimetre precision in position-fixing using satellite-based techniques, a wider deployment of broad-band seismometers, better understanding of the implications of micro faulting, and so on, there is currently a rapidly expanding effort by a wide range of scientists in collecting data. However, there is a lack of coordination and direction to ensure that the data are collected in the best possible manner to address the geoscientific problems from a continent-wide perspective - hence the need for ANTEC (see recommendation at the end of this report).

11. GOSEAC

D W H Walton, Convener of GOSEAC, addressed the joint WGs on environmental protection matters and gave a brief introduction to the way in which the ATCM is handling these issues. Progress seemed to be slow and there was concdern that few experts who could change on a daily basis implied a lack of efficiency and scientific authority. The general impression was that there will be ever tighter environmental controls on research. Of special concern to the geoscience community was that the CEP can designate sites and may turn its attention to geological sites. The question for the geoscience community is, 'Will we be consulted?'

The Annex on Environmental Liability, has not made much progress.

12. Introduction of diseases to Antarctica

J Croxall of the SCAR Subcommittee on Bird Biology gave a short presentation, for information, on a workshop to be held in Australia in August 1998 on the topic of the Introduction of diseases to Antarctic wildlife. The Antarctic Treaty System has become aware of the initiative and has requested that the workshop should report directly to ATCM. There is now considerable concern that an over-reaction by ATCM could result in a requirement for all equipment and personnel to be disinfected before entry into Antarctica. Should that be required, the consequences for any scientific programme could become prohibitive.

13. Lake Vostok

Members were addressed by F Carsey of NASA on the development of micro probes and robotic techniques which might be used to explore the waters and sediment bed of Lake Vostok. The Jet Propulsion Laboratory (JPL) of NASA is interested in Lake Vostok as a possible analogue for Europa, moon of Jupiter, which is believed to be covered in a thick layer of ice over a layer of water . Many of the technical problems of investigating the two locations are similar, as also are the scientific questions, including whether there might be life beneath the ice.

A workshop in Moscow earlier this year attracted attendance mainly from Europe; a workshop is planned this autumn for the US. However, Members felt that more effort needs to be made to ascertain the total international scientific interest and there was a need for a fully international, multidisciplinary meeting. There was a strong feeling that we had to approach the problem with the utmost caution. One false operation could ruin the world's largest body of 'uncontaminated' fresh water of enormous scientific interest and potentially of major scientific importance. There are believed to be about 70 other lakes similar to Vostok in Antarctica; they are smaller and could be used as potential testing grounds - even then a careful assessment of the hydrological conditions would have to be made lest contamination of one lake passed to another. Apart from the necessary development of a sterile drilling system, Members urged that a great deal more site survey, particularly seismic and radio-echo sounding, should be undertaken before any drilling takes place. Caution is of the essence at all stages of the investigation.

14. Joint meeting with the Working Group on Geodesy & Geographic Information

A short, but very constructive meeting of the three working groups was held to inform each other of areas of potential mutual interest. Short presentations drew out a range of common issues.

The Working Groups on Geology and Solid-Earth Geophysics presented on ADMAP, ADGRAV, BEDMAP, ANTEC, and the Geoscience map catalogue.

The Working Group on Geodesy and Geographic Information presented on: GIANT, ADD, SCAR Gazetteer, Antarctic Spatial Data Initiative, and RAMP.

The need for closer collaboration was identified in relation to map databases, the collection of gravity data in refining the reference geoid, differential GPS measurements in relation to continental movement, and the value of satellite radar imagery (RAMP) in imaging the bedrock surface beneath the ice sheet. Members were able to suggest cross disciplinary contacts enabling immediate collaboration.

Recommendation

Recognising

The working Groups on Geology, Solid-Earth Geophysics, and Geodesy and Geographic Information recommend that a Group of Specialists be established to address Antarctic Neotectonics (ANTEC)