Three to five million years ago, when carbon dioxide concentrations in the atmosphere were similar to those predicted for the end of this century, the enormous ice shelf buckled several times, triggering the collapse of West Antarctica.
Ice cores collected from the island reveal what ocean conditions were like over the tens of thousands of years, giving an indication of how sensitive the ice is, and what might happen if history is repeated.
Most of the West Antarctic ice sheet is now grounded up to 2000m below sea level.
"The reason they are so vulnerable to collapse is that warm water can melt them from below — a lot more efficiently than warm air from above — and even sliding ice into the ocean will add its weight instantaneously to sea level increases," said Dr Nancy Bertler, of Victoria University's Antarctic Research Centre.
This month, she and her team finished processing ice cores, taken from a depth of 763m at the bottom of the island and kept in a cold storage cave at a temperature of minus 27°C.
The record contained in the ice was much longer than Dr Bertler had expected, and appeared to stretch back to the critical time in question.
2. Up, up and away
Climate research by a Kiwi firm will benefit from internet giant Google's launch of large numbers of balloons from the South Island.
Google is launching balloons from Tekapo Airport in a bid to bring internet access to the remotest of places.
For research agency Bodeker Scientific, those that drift over Antarctica will collect invaluable information about the continent's atmospheric conditions.
A system called "stratospheric transport" largely determines the distribution of radiatively active gases and their effect on the warming of the atmosphere, and the long-duration stratospheric balloons will reveal, in detail never before seen, the transport processes and small-scale processes active in the southern high-latitude stratosphere.
Dr Greg Bodeker said it was well-understood there was a hole in the ozone layer above Antarctica, and this was contained by a vortex of winds blowing through the stratosphere over the continent.
As the balloons drifted over, the temperature and pressure readings they recorded would help scientists answer, among other questions, whether this natural containment was persisting or changing.
Bodeker Scientific's project has been funded by the New Zealand Antarctic Research Institute.
3. Going to extremes
Jutting out of Antarctica at the northwest corner of the Ross Sea, Cape Adare is one of the most extreme places on Earth.
The weather is poor half the time, storms are frequent, and the beaches are often swept by waves filled with floating ice.
But this hostile environment is also one of the best vantage points for observing the Antarctic ecosystem.
This is because the cape is the closest point in Antarctica to the shelf edge and slope and gives access to circumpolar deep water through nearby Robertson Bay.
It also has a 428,516 breeding pair colony of Adelie penguins.
The NZ Antarctic Research Institute plans to establish a monitoring point on the cape to pick up changes in any part of the ecosystem or physical system.
Institute director Professor Gary Wilson said a group of principal investigators would lead monitoring of areas including top predators, oceanography, coastal ecology, climate and soils.
"What we are undertaking is a pilot programme to make a set of scientific observations and measurements so we know what species we have there, which we can use in a longer-term monitoring programme," he said.
"A station will provide easy access to develop a time-series of measurements of a range of environmental processes, condition and different species including several iconic species such as the Adelie penguin colony at Adare, which is the largest Adelie penguin colony in Antarctica."
4. Taking the plunge
While most of us would rather leave it to the penguins, diving deep into freezing Antarctic waters is what Kiwi researchers are doing in the name of science.
In October, a group of scientists from the National Institute of Water and Atmospheric Research (Niwa) and specialist divers will return to the ice for the second stage of a series of experiments.
The team will camp for a month at Granite Harbour, about 100km from Scott Base, and will dive beneath the ice to look at how climate change and ocean acidification could affect this fragile ecosystem.
The divers make a hole by drilling and melting the ice, before plunging into waters as cold as nearly minus 2°C, limiting each dive to about 40 minutes.
Niwa has developed under-ice chambers in which the temperature and acidity of seawater can be controlled, enabling the team to measure the effects of specific changes on ecosystem processes, such as primary production by algae growing on the underside of the sea ice.
Niwa marine ecologist Vonda Cummings said areas like the Southern Ocean around Antarctica would feel the effects of increased acidity in the ocean more quickly than warmer areas.
"Experiments have indicated a number of species will be affected, but overall effects on marine ecosystems are unknown," she said.
5. Help from the seals
Weddell seals are hardy creatures. Diving deep under the ice of the Ross Sea, they inhabit some of the coldest, darkest waters on the planet.
But as mammals, they must surface to breathe — and it's partly for this reason that they're proving useful to scientists looking for large-scale change in the Antarctic environment.
Dr Regina Eisert, of the University of Canterbury's Gateway Antarctica, is studying the diets of the seals and other predators, to better understand the food web in the Ross Sea.
Global currents linking all the world's oceans are born in the waters surrounding Antarctica, and understanding how, where and when these currents form is central to understanding changes in global climate.
Dr Eisert has been working with Professor Mark Hindell and Dr Clive McMahon of the University of Tasmania in tracking seals through satellite-linked data loggers on their heads.
When the seals surface, the loggers transmit oceanographic data on depth, water temperature and salinity, collected as the animals swim beneath the ice.
"Recruiting seals as oceanographic observers not only produces a wealth of new data, but also tells us where they go to feed, highlighting particularly productive parts of the Southern Ocean," Dr Eisert said.
"This information is revolutionising our understanding of the oceans and how the parts of the ecosystem interact."
6. An online guide
New Zealand has a world-wide reputation as a leader in science on the ice, and now a Kiwi-developed portal will bring together work from other nations.
The Antarctic Environments Portal, a joint project between Antarctica New Zealand and Landcare Research, will put a mass of up-to-date research at the fingertips of policy makers when it goes live in 2016.
Its final version will include areas for science-focused discussions, and an interactive map enabling users to explore the continent and view information in four languages.
Antarctica New Zealand environmental consultant Dr Neil Gilbert said there had been rapid changes in ocean and air temperature, sea ice extent and species distribution, and further transformation would come over the next century.
"To ensure that policy debate and management decisions can keep pace with these changes in Antarctic environments, an effective means of collating summary information on the state of Antarctic environments is needed," he said.
"The portal will increase the speed with which information ... becomes available to policy makers."
7. Trees frozen in time
The Friis Hills of Antarctica's windswept Dry Valleys are home to exquisitely preserved remains of mosses, beetles and stunted beach trees that have been locked within glacial deposits for between 14 and 19 million years.
Professor Tim Naish, of Victoria University's Antarctic Research Centre, is analysing these fossils to understand how Antarctica's ice sheet and climate responded when the world last had the same amount of carbon dioxide in the atmosphere as it does today, but was some 3C warmer.
"The Friis Hills have these unique layers of geological strata representing times of ice sheet advance and retreat when the climate was warmer many millions of years ago," he said.
"Shallow glacial lake sediments are beautifully preserved and these contain plant and animal fossils representing one of the last known occurrences of trees on Antarctica, which are hypothesised to have become extinct about 13 million years ago."
This season, Professor Naish and his team will drill short cores out of the glacial deposits to analyse for climate history, and will make a seismic survey to establish the extent of the deposits.
Joining the team will be Victoria University senior lecturer Rebecca Priestley, who will film material for an online teaching and science communication course for students.
8. Inside the big glacier
At about the size of France, and up to 600m thick, the Ross Ice Shelf is an enormous chunk of ice.
But what happens when this vast structure shrinks?
Previous research has shown the shelf has grown and subsided many times, pushing up local sea levels and changing weather patterns.
After drilling into the shelf to collect samples, a research team will create computer models to better predict how much of the Ross Sea section of the West Antarctic ice sheet will change — and how quickly — as the planet continued to warm.
"The geologic record tells us that the West Antarctic has deglaciated under climate regimes similar to today's, and we infer from that record that the ice sheet may contribute metres per century to global sea level," said Otago University geophysicist Professor Christina Hulbe, who is leading the three-year project.
But scientists did not know the most probable rates of change.
"The ice sheet is going to keep changing, but will it contribute a centimetre a year to sea-level rise, or more, or less?" Professor Hulbe said.
"There is cause for concern and it matters to do the hard work to quantify it."
Two major summits first for NZ
The biggest scientific issues facing Antarctica will be thrashed out when close to 1000 of the world's experts arrive here for two major summits.
For the first time, New Zealand is hosting both the Scientific Committee on Antarctic Research (Scar) Open Science Conference (in Auckland) and the Council of Managers of National Antarctic Programmes (Comnap) Symposium and annual general meeting (in Christchurch).
"This is an unprecedented concentration of expertise and focus on Antarctica that reflects the importance of Antarctica and the Southern Ocean to the whole world," said Peter Beggs, chief executive of Antarctica New Zealand.
That it was being hosted here was in part a reflection of New Zealand's global leadership in environmental protection of Antarctica, he said.
It comes as the National Science Challenge addressing Antarctic climate science, dubbed "The Deep South", was officially launched in Wellington.
A major article in the journal Nature this month by 75 scientists also highlighted research focuses, among them human impact, understanding the evolution of Antarctic life, the region's history and impact of climate change.
It also called for greater international collaboration between scientists, and for environmental protection measures to be strengthened.
Earlier this year in Queenstown, the most important research questions surrounding the continent over the next two decades were set out at the inaugural Antarctic and Southern Ocean Horizon Scan retreat.
The findings, involving 100 questions relating to changes in sea ice, ocean, atmosphere and more, will form a keynote feature of the Scar conference opening in Auckland this weekend.
Scar convener Professor Bryan Storey, director of Canterbury University's Gateway Antarctica, described Antarctica as the "keystone" and most vulnerable part of global ocean and climate systems.
"What happens in Antarctica affects the rest of the world and Antarctica is changing," Professor Storey said.
"The Scar Open Science Conference will see the best scientists in the world presenting papers and engaging in symposia that will help inform our understanding and plan for the future of this predominantly frozen continent."
Why Antarctica matters
Professor Tim Naish, who heads Victoria University's Antarctic Research Centre, will be presented the prestigious Martha T. Muse Prize for science and policy in Antarctica at a global conference in Auckland next week. He shares with the Herald five reasons Kiwis should care about his research on the ice.
It could change the world's coastlines — "We still really don't know how the Antarctic ice sheets are going to contribute to sea level rise," Professor Naish said. The upper end prediction for sea level rise is about 1m by the end of the century. But if the vast West Antarctic Ice Sheet collapsed, the impact could mean 3m of rise.
Its past can tell us about our future — The globe is warming because of the amount of carbon humans have put into the atmosphere, yet it has been through the same from natural causes. Scientists will study the Pliocene period as its climate compares with what's predicted.
Its biology can pick up change early — "Often, biologists will say the Antarctic critters are the early warning signs, or sentinels of change. Changes to the food web could indicate ecological impacts from climate change."
It's the 'fly wheel' of the climate system — "The Antarctic is a very important cog in the climate engine; I think of it as a fly wheel because the oceans and atmosphere spins around it, transporting heat around the planet."
We need to understand its ozone hole — "The big question for us as climate scientists is will we see amplified warming in Antarctica? The ozone hole is suppressing things now, but that won't last forever, and the surface of the Southern Ocean will eventually warm."
