by University Communication
A University of Nebraska–Lincoln scientist will help lead a new multinational team that is drilling into Antarctica’s past to gain a glimpse at Earth’s future.
As the United Nations’ Conference of the Parties (COP26) focuses on science and national investment to combat climate change, researchers are preparing to drill into the ocean floor below Antarctica’s Ross Ice Shelf to discover if cutting greenhouse gas emissions could avoid catastrophic melting of the icy continent.
The Sensitivity of the West Antarctic Ice Sheet 2C project (SWAIS 2C) will investigate the ice sheet’s sensitivity to global warming of 2 degrees Celsius (3.6 degrees Fahrenheit), retrieving sediment from the depths to determine how the ice behaved when global temperatures were as warm as those expected in the coming decades and just above the 1.5 degree Celsius (2.7 degree Fahrenheit) target set by nations in the Paris Agreement five years ago.
Those geological records could reveal if there is a tipping point in the climate system beyond which large amounts of land-based ice melts, causing oceans to rise. The West Antarctic Ice Sheet holds enough ice to raise sea levels by about 13.1 feet.
David Harwood, a micropaleontologist and geologist at Nebraska, will be responsible for dating sediment cores and interpreting environmental changes on the new project. He will coordinate the geochronology of the cores and be one of the U.S. representatives on the science leadership team.
The researchers hope to recover about 200 yards of sediment, which will provide historical records that offer a study in contrasts: when large marine seas covered West Antarctica, versus when the ice sheet grew to its present size or larger. Harwood said the history will help scientists identify how the ice sheet may behave in the future, the timing and controls on what will cause its collapse, and how fast a collapse might occur.
“I’m a time traveler as a geologist, in that we are able to interpret past events that occurred long before humans impacted the world by reading history recorded in the sediments and rocks,” said Harwood, professor and T.M. and E.E. Stout Chair of Stratigraphy. “This past-looking perspective also allows geologists to look forward into the future, guided by our understanding of what happened in the past can and will happen in the future.”
Harwood said an important element of the work is improving numerical climate and ice sheet models so they can better predict the future.
The National Science Foundation will provide $680,000 in cash and resources-in-kind to support the drilling and field operations, with $340,000 awarded to the University of Nebraska–Lincoln to provide to the project operator in New Zealand, as well as $340,000 in aircraft flight hours that the U.S. Antarctic Program will provide to support field operations between the U.S. and New Zealand research stations and the remote SWAIS 2C field site.
In addition to the financial contribution for logistical support, the National Science Foundation will award $2.9 million in research support to the eight participating U.S. universities, including Nebraska, with the bulk of the funding going to a team of early-career scientists and postdoctoral researchers.
The SWAIS 2C team includes some of the world’s top Antarctic scientists, led by Molly Patterson of Bingham University of New York and Richard Levy of Victoria University of Wellington.
The international effort to recover sediments from the two drill sites is supported by $4.6 million in combined funding from New Zealand, the United States, Germany, Australia, the United Kingdom and South Korea, with several other nations planning to join. SWAIS 2C science leaders were successful in obtaining $1.2 million from the International Continental Scientific Drilling Program toward the drilling and operational field costs, the first for an Antarctic drilling program.
“We have formed a team of drillers, engineers, field experts and scientists who are up to the task,” Levy said. “Discoveries will show us how much the West Antarctic Ice Sheet could melt if we miss Paris Agreement targets.”
Patterson said geological data provides direct evidence regarding the extent of the ice during a given time period.
“This information is necessary to assess whether climate models are able to capture observed variability during warmer times in Earth’s history, prior to making any assumptions about the future,” she said.
750 miles across the Ross Ice Shelf, 0.6 miles down through ice and dirt
SWAIS 2C’s preparation team will depart from Scott Base next November for a 750-mile journey across the Ross Ice Shelf to the Siple Coast, where land ice meets the ocean and starts to float. Once the drilling camp has been established, the wider science team will join the group and work through Antarctica’s “summer” until February. SWAIS 2C field campaigns are planned for the next three years.
No one has ever drilled into the Antarctic seabed at a location so far from a major base or so close to the center of the West Antarctic Ice Sheet.
Engineers at Victoria University of Wellington’s Antarctic Research Center have spent four years developing unique technology capable of hot-water drilling through roughly 880 yards of ice before taking sediment samples from as many as 220 yards beneath the ice sheet.
“The fact that so many countries are joining us in this effort highlights the urgency to understand more about the West Antarctic Ice Sheet, which remains the largest uncertainty for sea level rise projections,” said Rob McKay, director of the Antarctic Research Centre in New Zealand. Sediment could help scientists understand how much Antarctic ice melted when the world’s climate was warmer. That, in turn, should help scientists predict what might happen if global temperatures continue on their current trajectory toward 2.7 degrees Celsius (4.86 degrees Fahrenheit) above pre-industrial levels.
Antarctic ice melt raises sea levels around the globe. The West Antarctic Ice Sheet is considered vulnerable to climate change because much of the ice, which rests on bedrock thousands of feet below the sea level, is exposed to the warming Southern Ocean.
Victoria University of Wellington’s Tim Naish, program leader for the Antarctic Science Platform, said the project will address two of the biggest questions concerning climate scientists and humanity: “Did the West Antarctic Ice Sheet collapse the last time the Earth warmed? Can we save the Antarctic Ice Sheet if nations meet the Paris Agreement targets?”
Building on ANDRILL
The new project builds on the international collaboration developed during the Antarctic Geological Drilling, or ANDRILL, program, which was managed by Harwood out of Nebraska’s Antarctic Science Management Office from 2001 to 2015. This time around, Harwood said, the team will be using a different and smaller drilling rig, and researchers will be working farther into the deep field.
“We learned a lot with ANDRILL, specifically that the West Antarctic Ice Sheet had a dynamic history of ice volume changes,” he said. “ANDRILL science outcomes led to substantial improvement in numerical climate and ice sheet models, with the addition of ocean heat into model simulations of past and future ice sheet behavior.
“The SWAIS 2C Project will continue to investigate where ANDRILL left off, with the collection of new drill-core records that will also lead to improvements in model skill to ‘back-cast’ and forecast ice sheet behavior under warmer ocean and atmospheric conditions expected in the coming decades.”
The new project’s leadership has close ties to the University of Nebraska–Lincoln and ANDRILL. Levy was the staff scientist for ANDRILL and received his doctoral degree in geology from Nebraska. As a graduate student, Patterson likewise worked with ANDRILL.
Harwood will also lead some of SWAIS 2C’s education and outreach efforts, another important aspect of ANDRILL’s legacy.
“One of the lasting elements of ANDRILL was the large effort toward polar science education and outreach and climate change science,” he said. “As part of Nebraska’s contribution to the new project, we will be reconnecting with the ANDRILL teacher network across the United States and developing new content that aligns with Next Generation Science Standards and includes current climate change components, including new data and results from the SWAIS 2C Project.”
Harwood said he’s excited to produce new findings that can advise policymakers, such as those working at the United Nations’ climate change conference, and revive past efforts to inform and engage students, teachers and the public.
“It is great to see this project launching finally, after a long time in development,” he said. “It is especially great to see so many young, keen scientists from many nations working together to address important questions that are facing humanity in the climate crisis.”
The National Science Foundation is providing a total of $3.2 million to support U.S. scientists and SWAIS 2C logistics, operations and drilling costs, as a contribution to the international pooled funding. Support to U.S. institutions will be made through awards NSF-OPP 2035035, 2034719, 2034990, 2034996, 2034999, 2035029 and 2034883.
by University Communication