Australia National Report
Prepared by: Ian D. Goodwin
Australian scientists have been involved with ITASE related research in a number of geographic locations during the period 1997-2002. These include: Wilhelm II Land, Amery Ice Shelf, Law Dome, eastern Wilkes Land, Terre Adelie, George V Land and Northern Victoria Land.
1. WILHELM II LAND
In the summer of 1997/1998 Australian Antarctic Division extended its shallow snow-sampling program from its ongoing monitoring at Law Dome (Dome Summit South) to Wilhelm II Land, and the Amery Ice Shelf, using logistical support from other projects in these vicinities.
Twenty-one shallow cores were collected in Wilhelm II Land during the summers 1997/1998 and 1998/1999 using helicopter flights from Davis Station. The flights were also in support of ice radar surveys between Mirny and Davis Stations. Each core site was marked with a stake and revisited in subsequent summers for accumulation measurements. Ice core analysis was undertaken at the Antarctic CRC.
2. AMERY ICE SHELF
Helicopter operations from Davis Station also facilitated the collection of two shallow cores from the northern end of the Amery Ice Shelf in the summer of 1998/1999 during field surveying projects. In each summer 1999/2000, 2000/2001 and 2001/2002 a shallow core was collected at the AMISOR hot water drilling sites. Analyses of these cores are still in progress.
3. LAW DOME
Continued sampling has been undertaken around the DSS site near the summit of Law Dome with intermediate and shallow coring, as well as shallow snow pit sampling. This site is visited by over-snow traverse at least every second year to maintain a continuous record of accumulation to add to the paleo-record obtained from the DSS ice core (1260 m completed in 1993). Some results from this work have been published (see below); other analyses are still in progress.
4. EASTERN WILKES
Laboratory analysis of major ion chemistry was completed on the GD09 (69° 00' S, 124° 03'E, 2138 m) firn core at the Laboratoire de Glaciologie et Géophysique de l'Environnement, France. A 57 year record spanning 1985 to 1927 was interpreted from the data and a paper is in preparation.
Planning is underway for an fixed-wing air supported ITASE traverse in eastern Wilkes Land in 2003-2004. At least 2 medium depth (200-300 m) ice cores are planned to be retrieved from sites along 68°S and between 125°E and 135°E.
5. REPORT ON AUSTRALIAN- US COLLABORATIVE ITASE FIRN CORE DRILLING IN TERRE ADELIE/GEORGE V LAND AND NORTHERN VICTORIA LAND, DECEMBER, 2000
ITASE firn core drilling was conducted on the southbound DF01 voyage of the US Coastguard Cutter Polar Sea, 14 to 30 December, 2000. The aim of the drilling was to access remote locations along the East Antarctic coast on an opportunity basis. Each of the selected sites was at a locations where complementary science or logistical activities were scheduled. The ITASE scientific work was also conducted as a pilot study to determine whether the US Coastguard Cutters were suitable platforms for the execution of continent-based drilling projects.
ITASE FIELD ACTIVITIES
ITASE firn coring activities were planned at three locations:
6. Mertz Glacier,
(67.5°S, 143.3°E) and Madigan's Nunatak (67.2°S, 143.3°E)
region, Terre Adelie/George V Land coast;
7. Buckle Island(66.8°S, 163.3°E), and Sturge Island (67°S, 163° 25'E,) in the Balleny Islands; and,
8. Hallett Plateau (72.5°S, 170.1°E), Northern Victoria Land.
At each of these locations it was proposed to hand auger at least one drill hole to depths of 10-12 m, using the PICO lightweight auger. The success of these plans were dependent upon available time, meteorological conditions and logistics.
It was scheduled that the Mertz Glacier work would be carried out in association with the University of Wisconsin's program on Automatic Weather Station (AWS) maintenance, and two Antarctica New Zealand projects on Adelie Penguin studies. Two helicopter flights were deployed with the ITASE group to undertake firn core drilling on the East Antarctic plateau and Mertz Glacier basin, towards the end of the stationary ship time. However, whiteout conditions prevented access to the Mertz Glacier interior and only a short 6 m core was obtained from inland of Watt Bay at a lower elevation of 563 m, adjacent to the Mertz Glacier basin. The ship departed the George V Land coast shortly after the two attempts.
ITASE firn coring was scheduled on an opportunistic basis during the one day visit to the Balleny Islands en route to Cape Adare. One helicopter flight was organised for firn core drilling on the summit of Buckle Island (66° 46.8'S, 163° 20'E, 900 m), and a reconnaissance of potential drilling sites on the larger Sturge Island (67°S, 163° 25'E, 1500 m). Unfortunately, cloud cover over the summit plateaux of both islands prevented a landing and no drilling was accomplished. However, the flight did provide an excellent opportunity to survey potential drilling sites, on these remote islands. Future ice coring on the Balleny Islands would provide an important insight into precipitation rates in the Southern Ocean region.
Cape Hallett and Hallett Peninsula
The Polar Sea was required to transport fuel drums to Cape Hallett. This operation took approximately 12 hours in total. During this time the ITASE crew were transported by helicopter from the Polar Sea to the Hallett Plateau (72.5°S, 170.1°E). A 12 m firn core (HA1) was successfully retrieved from this location in perfect weather conditions. Reconnaissance investigations of the surface glaciology were also conducted. The entire mission took less than 4 hours.
Ice Core Analysis
Laboratory analyses including: major chemical ions, visible layer stratigraphy and density, were completed on the HA1 core during 2001-2002. The data are currently being analysed together with climate data, and a paper is being prepared.
Table: Summary of field work and publications of Australian Antarctic Division
|Location||Year Collected||Sample Type||Publications
|Dome Summit South, Law Dome||1997/1998||1 x 200 m eclipse drill core (DSS97)||1-6|
|1997/1998||1 x 70 m eclipse drill core (DSSW20k)|
1 x 120 m thermal drill core (DSS99)
|1999/2000||1 x 10 m PICO core|
|1999/2000||Multiple shallow cores (to 6m) and snow pits (to 2.5m)|
|2001/2002||1 x 10 m PICO core|
|2001/2002||Multiple shallow cores (to 6m) and snow pit (to 2.5m)|
|Wilhelm II Land||1997/1998||6 x 5 m PICO cores||7,8|
|1998/1999||14 x 5 m PICO cores|
|1998/1999||1 x 10 m PICO core|
|Amery Ice Shelf||1998/1999||2 x 5 m PICO cores||Nil|
|1999/2000||1 x 5 m PICO core|
|2000/2001||1 x 5 m PICO core|
|2001/2002||1 x 5 m PICO core|
1. Mark A.J. Curran, Anne S. Palmer, Tas D. van Ommen, Vin Morgan, Katrina L. Phillips Alison J. McMorrow and Paul Mayewski. Post-depositional methanesulphonic acid movement on Law Dome and the effect of accumulation rate. Annals of Glaciology 35 (in press).
2. Anne S. Palmer, Vin Morgan, Mark A. J. Curran, Tas D. van Ommen & Paul A. Mayewski. Antarctic volcanic flux ratios from Law Dome ice cores. Annals of Glaciology 35 (in press).
3. Alison J. McMorrow, Mark A. J. Curran, Tas D. van Ommen, Vin Morgan and Ian Allison. Features of meteorological events preserved in a high resolution Law Dome Snow pit. Annals of Glaciology 35 (in press).
4. Palmer, A.S., van Ommen, T.D., Curran, M.A.J., Morgan, V, Souney J and Mayewski P. High precision dating of volcanic events (A.D. 1301-1995) using ice cores from Law Dome, Antarctica. J. Geophy. Res. 106 , No. D22 , p. 28089-28096. 2001.
5. McMorrow, A.J., Curran, M.A.J., van Ommen, T.D., Morgan, V., Pook, M.J. and Allison, I. Intercomparison of Firn Core and Meteorological Data. Antarctic Science 13 (3) 329-337 2001.
6. Palmer, A.S., van Ommen, T.D., Curran, M.A.J. and Morgan, V. Ice-core evidence for a small solar-source of atmospheric nitrate. Geophys. Res. Lett. Vol. 28 , No. 10, p. 1953. 2001.
7. Smith B. and Ruddell A. 2001. Snow accumulation in Wilhelm II Land, East Antarctica. Antarctic CRC Research Report 22.
8. Smith B.T., van Ommen T.D. and Morgan V.I. in press. Distribution of oxygen isotope ratios and snow accumulation rates in Wilhelm II Land, East Antarctica. Annals of Glaciology 35.
9. Goodwin, I. D., de Angelis, M., Pook, M. and Young, N.W. ( In prep). Snow accumulation variability in Wilkes Land, East Antarctica and the relationship to atmospheric ridging in the 130° to 170° E region. To be submitted to Journal of Geophysical Research.