By Virginia Dean, Standard Correspondent
The Danish country of Greenland is the world’s largest island, over three-quarters of which is covered by the only contemporary ice sheet outside of Antarctica which, as local resident and scientist Dr. Nicholas Beaird knows well, has depressed the central land area to form a basin lying more than 900 feet below sea level.
“Almost all of the land in Greenland is covered by ice,” said Beaird in a recent interview, “and this is especially true on the East Coast which is incredibly rugged and remote. Just a few miles inland all the land is completely covered and you just see a featureless white expanse of ice. Nearer the coast, mountains poke through the ice sheets in places. The flat ice sheet drains into fast moving ice streams or glaciers near the coast.”
An oceanographer and postdoctoral scholar and investigator from the Department of Physical Oceanography of the Woods Hole Oceanographic Institution, Beaird — along with his colleague Rebecca Jackson, a PhD candidate in physical oceanography at the Massachusetts Institute of Technology — are currently researching the speed at which this ice sheet is melting and why.
The two scientists will be presenting their findings Nov. 14 at the Norman Williams Public Library from 4:30 to 5:30 p.m.
Although some scientists believe that the accelerated rate of ice sheet melt might be due to warmer waters melting on the underside of the ice, little is really known about underlying reasons, for scientists have limited information about the ocean temperature or circulation around the glaciers which they think actually impact the rate at which the ice recedes.
“In general, we know very little about how the relatively warm ocean and the huge mass of ice atop Greenland interact,” said Beaird. “From observations made like those we made from the helicopter, we know warm ocean waters reach the 600-meter vertical wall of ice at the end of Helheim Glacier carrying enough heat to do a significant amount of melting. How might the delivery of that heat affect the stability of the glacier? Could changes recently observed in the ocean offshore cause changes in the rate of ice melt on Greenland? How does the freshwater produced when the glacier melts into the sea affect ocean circulation? These are some of the big questions our group and others are trying to answer.”
The Helheim Glacier is a flow of ice that originates from the ice sheet through a narrow rift in the coastal mountain range and down into the sea at a rate of several miles per year. In recent years, it has dramatically accelerated its retreat increasing, for example, nearly two miles a year from 2000 to 2005. It also allegedly thinned by 130 feet between 2001 and 2003. Scientists remain concerned that the effects of the glacier’s retreat will continue to move inland ultimately decreasing the thickness of the entire ice sheet. Over the last ten years, the margins of this sheet have been thinning by tens of meters.
Aside from warmer air and water temperatures, research studies have indicated that there is a relationship between the retreating front of outlet glaciers such as Helheim and an increase in the rate of flow.
Perhaps alarmingly, the ice sheet of Greenland is melting at four times the rate it was in the 1990s, currently contributing twice as much to observed global sea level as melting glaciers in Antarctica, Beaird related.
“There are indications that it is draining freshwater into the North Atlantic ocean in quantities nearly large enough to disrupt large scale ocean circulation according to (Bristol University Professor) Jonathan Bamber,” said Beaird.
Making observations near the interface between ocean and ice helps scientists achieve their goal of understanding and possibly predicting future changes in the ice sheet that generally flows to the coast from the center of the island, Beaird said.
“Predicting the future of the ice sheet alone doesn’t give us any control over what happens down the road,” he said. “But just as with a weather forecast, the prediction helps us intelligently prepare for the future.”
Jackson has indicated, however, that forecasting a plan can be difficult because the iceberg-laden fjords that are the results of the moving glaciers are difficult to access and remain largely unexplored. Thus, measurements of warming trends around Greenland have been made in the ocean off the coast outside the fjords and far from the ocean/glacier interface.
“A few scientists have begun studying these fjords by making measurements during brief summer surveys,” said Jackson. “But just as recording the weather in Boston for a few days during the summer will not tell you much about Boston’s climate or temperature fluctuations, neither do snapshot surveys of fjords tell us much about temperature variability near vulnerable glaciers.”
Thus, Jackson’s research group leaves instruments in fjords throughout the year, measuring ocean currents and water temperatures that drive melting at the glacier’s edge.
She and Beaird work out of a town called Tasiilaq, the largest on the East Coast with a population of about 2,000. Greenland itself has an overall population of about 56,000, most of whom are Greenlandic Inuit.
“The town is built around a harbor on a steep hill,” said Beaird. “It’s incredibly beautiful with glaciercovered jagged mountains all around the town and an iceberg choked bay. The only colors in Greenland are white, rock gray, and blue so it’s shocking when you get to a town like Tasiilaq where the little houses are painted bright red, yellow or green.”
To access the town, Beaird noted, one has to fly to a large airstrip that was built by the United States Air Force during World War II.
“The airstrip is quite far from town and because there are no roads in Greenland except the street within towns, you have to take a helicopter from the airport to get into it,” said Beaird. “Greenland is a really beautiful place, but it very much feels like the end of the earth.”
Beaird is the son of Woodstock resident Kathy and Brooke Beaird, who said Nicholas’s research has led to such adventures as hanging out of helicopters deploying instruments to gather critical data, chasing errant gliders deep in the rough North Sea, and navigating through sea ice and icebergs in old Soviet trawlers converted to scientific research vessels.
Nicholas was born in Woodstock but left when he was quite young.
“He always loved Vermont and was very happy when we returned 26 years later to retire,” said Kathy.
Jackson grew up loving the ocean and has been teaching sailing — competitively and noncompetitively — since her teens. She will be working on her postdoctoral research at Oregon State University with a team examining the fluid dynamics of water flowing from Alaska’s glaciers.
She joined the Oceanographic Institute after completing a bachelor’s degree in physics at Yale University in 2010. Her current research focuses on investigating the circulation of Greenland’s glacial fjords and, in particular, the combined glaciological and oceanographic forcings.
As an oceanographer, Beaird has been interested in the circulation and processes of the high latitude ocean. He joined the Institute in 2013 after completing his PhD at the University of Washington.
This article first appeared in the October 29, 2015 edition of the Vermont Standard.