What is ANDRILL?
ANDRILL (ANtarctic geological DRILLing) is an international science programme comprised of more than 200 scientists, students, and educators from five nations (Germany, Italy, New Zealand, the United Kingdom and the United States).
Scientists from GNS Science have been involved in the leadership, fieldwork and science of the ANDRILL programme. Our GNS Outreach Educator Julian Thomson also went down to Antarctica for two summer seasons to work with the scientists - see Julian's ANDRILL blog ( http://www.andrill.org/iceberg/blogs/julian/ )
Ground Breaking Research
By drilling into the rocks hidden beneath the ice of the Antarctic margin, ANDRILL has been finding out about how Antarctica changed through the last 20 million years. This research has improved our understanding of Antarctica's geological history and the impact of past climate changes on the huge Antarctic ice sheets. This knowledge is helping us understand how Earth's environments might change in response to current and future global warming.
ANDRILL's first two drilling projects retrieved the longest, most complete geological rock cores in Antarctica. Both expeditions drilled through ice and sea water in the Ross Sea near New Zealand's Scott Base and the United States McMurdo Station to get to rocks beneath the sea floor:
McMurdo Ice Shelf Project Drilling (2006-2007)
- Ice Shelf thickness 85 metres, water depth about 1km
- Deepest geological borehole in Antarctica - Drill depth 1285m below sea floor.
- Rocks sequence recovered to over 13.5 million years old
- In cold glacial phases the ice was thick enough to be grounded on the sea floor 1km below present sea level
Southern McMurdo Sound Project Drilling 2007-2008
- Sea Ice thickness about 8.5m, water depth about 380m
- Deepest geological borehole from sea ice - Drill depth 1140m below sea floor
Rock sequence recovered to over 20 million years ago
What does this add up to?
ANDRILL's technological and scientific efforts provide us with a unique window into Antarctica's climate history.
- Between about 3 - 5 million years ago when global average temperatures were 2 - 3°C warmer than present, the whole West Antarctic Ice Sheet was a dynamic feature - appearing and disappearing regularly over natural cycles of about 40000 years.
- At least 40 of these major ice advances and retreats are recorded in the ANDRILL's MIS Project rock core over the last 5 million years. However - the record is incomplete, large pieces of geological time are not recorded due to missing sediment, and there must have been many more such cycles of ice sheet growth and collapse.
- In the 'warm' phases, West Antarctica would have been an archipelago of islands snow capped looking much like Patagonia does today.
- These changes in ice sheet size would have caused sea level to rise and fall by up to 6 metres.
- During this period of relative warmth, carbon dioxide levels in the atmosphere were above present levels - but within the range of predicted levels for the end of this century.
- Scientists are interested to examine and understand these past climates to help understand potential future global changes under increased global temperature and atmospheric CO² levels.
- Initial results from the SMS Project suggest that around17.5 million years ago climatic conditions in the Ross Sea region were similar to those that characterize the coastal margin of South Western New Zealand today.
For Teachers and students wanting to learn more about Antarctica and geological drilling see our classroom activites and have a look at our Expedition Gallery of photos taken from down on the Ice.
There are lots more interesting educational activities that have been developed around the ANDRILL Programme, by the team of educators who went down to the ice and worked with the scientists.