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This symposium attracted a 'full house' of 134 participants, many of them from interstate, and maintained the levels of quality and excellence which have become its hallmarks. In the process it also managed to establish a couple of 'firsts' which will help enhance its reputation for the future. It was the occasion for the inaugural award of the Selwyn Memorial Medal to Fons VandenBerg and it also featured a small, varied, excellent exhibition of technical posters, historical material, rocks, fossils, stamps and other paraphernalia from the Antarctic. Fine weather, good outcrop and some unscheduled mid-day entertainment (by courtesy of Bob Tingey) ensured that the excursion to the glacial deposits of the Bacchus Marsh area under the leadership of Phil O'Brien (AGSO) was a rip-roaring success. The comprehensive excursion guide is, unfortunately, sold out. However, the Extended Abstracts Volume are can be downloaded as a PDF file (6.2 Mb). Jim Bowler (Melbourne University) gave the keynote address: Antarctic ice cap origins: global thermostat and sea level controls in evidence from southern Australia. Other presentations were: |
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| The technical sessions were capped off by the Selwyn Memorial Lecture, presented by Prof Pat Quilty of the Australian Antarctic Division. |
| 1996 SELWYN LECTURE: The big questions in Antarctic geoscience |
| Patrick G. Quilty, Australian Antarctic Division, Channel Highway, Kingston, Tasmania 7050 |
| There is a sense in which we can see geology as the centrepiece of science, divided into a series of subdisciplines such as oceanography (to contribute to what we know of the watery part of the planet), meteorology (to understand the atmosphere), and biology (to understand the living part of the planet). The above sciences give an understanding of the way the planet works now; geology adds to this the element of time—4.6 x 109 years. To give an idea of the import of this, note that it has been estimated that for every species that exists today, 100 000 000 have become extinct. Biology x 108. In this sense, it is the magnificent integrating science—nothing can match it in the planetary context. When A.R.C. Selwyn resigned his post in 1869, he left Victoria with his summaries of the geology of the colony as a consolidated foundation on which following generations of geologists could build. We find ourselves in a similar state today in relation to Antarctica. A generation of scientists, first active in the 1950s, 1960s and 1970s is moving out to make way for a new generation, trained in new ways and with different approaches. For the geologists, they have, as the equivalent of Selwyn's works but on a larger scale, The Geology of Antarctica edited by Bob Tingey. This will stand for a long time as a monument to Bob's ability as a geologist and integrator. He has been a major shaper of Antarctic geosciences, both nationally and internationally. But how shall we build on this foundation? |
Not
only have scientists changed but so have administrators and the way
that science is justified and funded. Nonscientists are taking a far
greater role in deciding the directions of science and the questions
that will be answered by scientific endeavour. Antarctica raises special
problems because of the cost of logistics, the decreasing availability
of those logistics and thus the increasing pressure to put priorities
in science, when the amount of science to be done is immense, when
the interest is high, but the number who can be supported is so few.
In this context, geologists and geophysicists have to justify their
science in new ways. It is no longer appropriate to study something
because it is very interesting or because it is there. It must be
justified in terms of contributing answers to big questions. Thus
the first big question is how do we convince administrators/bureaucrats
of the value of a geological perspective on questions they have? We
all must become active in this pursuit. The geological sciences are
expensive because of the need for alarge logistics support base to
cover the Australian Antarctic Territory (AAT). Thus separate funding
resources are needed beyond those required for station operated science.
There is urgent need for new blood which will work in areas of the
geological sciences that are neglected at present. Some of the new
directions should include integration of the geological perspective
with other disciplines in both fieldwork and in the science itself. |
| Criteria for judging what are Big Questions |
Big
Questions or Key Issues are influenced by several factors including
immediate need identified by the bureaucracy or funding agency (for
example the recent emphasis on the Australian Offshore Territory initiative),
longer-term indefinite needs, contribution to international agreements,
scientific questions in their own right, public interest, and the
existence of a logistics base or equipment. Antarctica constitutes
about 8% of the world land surface area and the Antarctic, defined
to include the surrounding marine environment, also covers some 8–10%
of the world's surface. No compilation of any global feature can be
done without an Antarctic input. The Antarctic is globally important.
My comments must be skewed towards the area of interest of the Australian
program, that is the AAT. |
| Some Big Questions |
| Understanding
the way Antarctica is. This question is current internationally and
was considered by the Working Group on Geology at the recent meeting
of the Scientific Committee on Antarctic Research (SCAR). It can be
seen as part of the modern environmental state of Antarctica and includes
identifying the framework of the Antarctic, the cratonic structure
of Antarctica, its sedimentary basins and dynamics. This calls for
major initiatives in some of the solid-earth geophysics areas, particularly
seismology, aeromagnetics and gravity, and field work to translate
interpretations to reality. There is a very strong need to study the
seismological data gathered at Australian and other stations, to define
the structure of the crust. Aeromagnetic surveys are necessary to
help define the cratonic blocks that make up East Antarctica and gravity
studies should tell of its isostatic state. There is great scope to
incorporate the field side of this with the needs of other disciplines,
particularly glaciology. Geodetic studies at present underway need
to be enhanced to allow better understanding of the dynamic relationships
with surrounding oceans and other continents. GPS facilities have
been installed at all Australian stations and these will soon tell
of the dynamics between cratonic blocks and between Antarctica and
other parts of the world, including resolution of one of the more
pressing global questions concerning the expansion or static condition
of the earth's volume. |
| We
have installed tide gauges at Antarctic stations, partly to monitor
sea level change. With our current knowledge of the crust of Antarctica,
this is impossible. Understanding of the basement as an aid to modem
geodetic studies is important. |
Modern
processes active in the Antarctic, including landform development
and sedimentation processes, need to be documented fully at a variety
of scales to help studies into human impacts on the local scale and
the effects of continent-scale glaciation globally, now and in the
past. Study of the distribution of modern features and understanding
of modern processes are still in their infancy and need to be expanded
to allow us to gain an understanding of what happened in rocks we
find in Antarctica, and especially elsewhere on earth, now—the
present as the key to the past. Modern sediments and exposures provide
a substrate for plants and animals to live on and the location for
our human facilities. Understanding of the modern is important for
management reasons and as a basis for other sciences—the integrated
value. |
| Transition, from nonglaciated to glaciated Antarctica |
|
At
present, geoscience is supposed to concentrate on the last few million
years because of the interest in global climate change, but even this
cannot be understood or monitored adequately without an understanding
of some of Antarctica's older rocks and the way they react to change. |
The
concentration on the Neogene, while important because it allows documentation
of the earth in the recent glacial mode, has neglected the important
scientific questions of “How did the 'modern' environment evolve?”
and “What is the world like under different climate regimes?”
Can we find analogues of the environment the world is thought to be
evolving towards, and make a decision about whether humanity would
be happy (or at least content) to live in such a world? The Palaeogene
(and perhaps the Cretaceous) were times when the big changes occurred.
Australia and Antarctica began their separate existence allowing the
change to the modern pattern of ocean basins and global circulation.
The world's vertical ocean circulation pattern changed from one driven
by the low to mid-latitude generation of hot, high-density, high-salinity
water, to one driven by cold, high-density, high-salinity water generated
in the Antarctic. Deep oceans changed from filled with hot water to
filled with cold water. What effect did this have on the global CO2
regime during an interval when CO2 content of the atmosphere was 3–4
times that of the preindustrial era, and life flourished? What was
the trigger for the commencement of the development of the modern
icesheet? |
By
what path did the Antarctic fauna and flora become extinct? This was
the extinction of an entire continent's biota and took place over
about 20 million years. This was in contrast to 'normal' evolutionary
patterns of mass extinction or progressive change. As the terrestrial
biota became extinct, another, isolated from the rest of the world,
evolved in the marine realm. What was the path of this evolution and
what is the relevance to questions of fragility or robustness of the
modern ecosystem? |
| The question of the Pliocene environment of Antarctica is still with us, perhaps more pointedly than before and raising issues of when the Antarctic icesheet reached it present size, mid-Miocene or significantly later, of its dynamics, and of the history and global influence of Northern Hemisphere glaciation. It is slowly emerging that there has been a major extinction event since the early Pliocene. A cetacean fauna, key crustacean groups, many molluscs, perhaps terrestrial vegetation, all disappeared. Is this purely Antarctic or global, and when did it occur? |
It
is pleasing to see the international Antarctic community addressing
some aspects of this question, for example through the Ocean Drilling
Program and the Cape Roberts Drilling Program. Australia needs to
enhance its role in that international effort because it contains,
offshore of the AAT margin, some of the best places to get answers
to these questions. Gondwana questions. Antarctica is commonly referred
to as the keystone of Gondwana. That gives it a unique place in that
reconstruction. There are still major questions about the role of
Antarctica within Gondwana and the AAT can contribute to questions
because of excellent exposures in the Prince Charles Mountains. One
question that is complementary to that of the Cenozoic extinction,
is that of the processes that occurred at the end of the Gondwana
glaciation, as new biota evolved to fill the vacuum left by the extinction
of the earlier one. A very active debate is emerging about supercontinental
geometry in earlier times and Antarctica is a key player in answering
some of the questions. |
Antarctic
meteorites have assumed new significance very recently. The important
meteorite collections from Allan Nunataks are (just) from the Australian
Antarctic Territory and provide evidence of possible life elsewhere
in the universe, even in our own solar system. Australia has no Antarctic
meteorite program, even though the best collections in the world come
from theAAT, and Australia has a tradition and expertise in this area.
Areas around the Prince Charles Mountains must be considered as potential
new sites for meteorite recovery. |
Australia's
subantarctic islands have separate unique characteristics which have
caused them to be nominated for World Heritage status largely on the
basis of their geological features. There is scope tor research on
each in a variety of geological subdisciplines—volcanology in
all its manifestations, tectonics, landform evolution, sedimentary
and igneous studies. Who will do the work? The Antarctic role of the
Australian Geological Survey Organisation (AGSO) has been limited
by recent events. It will retain its lead agency/program leadership
role but there is a desperate need for new institutions to become
involved in the program and for a great expansion in the range of
studies to be undertaken. With a reduced government agency role, the
way is clear for the university/museum sector to take the initiative.
Traditional areas should continue to be supported, but priority must
be granted to some other research areas, particularly geophysics,
which are traditional research areas, but not so much in the Australian
Antarctic context. |
