A new study that analyzes ancient soil once stored at the University at Buffalo is causing a worrisome rethinking of the history of Greenland’s ice sheet and reveals its fragile nature today.
Joshua Brown, University of Vermont
Release Date: July 21, 2023
BUFFALO, N.Y. — Until recently, geologists believed that Greenland was a fortress of ice, mostly unmelted for millions of years. But, two years ago, using soil once buried a mile beneath the island’s ice sheet and later stored at the University at Buffalo, a team of scientists showed that it likely melted less than one million years ago.
Now, further analysis of the sediment has created a starker picture: Greenland was a green land only 416,000 years ago.
The team’s new study — published July 21 in the journal Science and co-authored by Elizabeth Thomas, associate professor of geology in the UB College of Arts and Sciences — presents direct evidence that the sediment was deposited by flowing water in an ice-free environment during a moderate warming period from 424,000 to 374,000 years ago.
“It’s really the first bulletproof evidence that much of the Greenland ice sheet vanished when it got warm,” says University of Vermont geoscientist Paul Bierman, who co-led the study with lead author Drew Christ, a postdoctoral geoscientist who worked in Bierman’s lab.
Elizabeth Thomas, Univeristy at Buffalo associate professor of geology, conducted chemical analysis that enabled the team to understand the types of plants that were on site. Credit: Douglas Levere/University at Buffalo
Understanding Greenland’s past is critical for predicting how its giant ice sheet will respond to climate warming in the future. The new study provides strong and precise evidence that Greenland is more sensitive to climate change than previously understood — and at grave risk of irreversibly melting off.
Since about 23 feet of sea level rise is tied up in Greenland’s ice, every coastal region in the world is at risk.
Under ice
Camp Century was a U.S. Army base on Greenland in the 1960s. It was the site of a secret operation, called Project Iceworm, to hide nuclear missiles under the ice near the Soviet Union.
The missile mission was a bust, but the science team did complete first-of-its-kind research, including drilling a nearly mile-deep ice core. The Camp Century scientists were focused on the ice itself, so they took little interest in the 12 feet of sediment gathered from beneath their ice core.
Engineers with the Cold Regions Research and Engineering Laboratory capture part of an ice core at Camp Century, Greenland, circa 1966. Credit: U.S. Army Corps of Engineers
Then, in a bizarre story, the ice core was moved in the 1970s from a military freezer to UB by then-UB geology professor, Chester “Chet” Langway, who was one of the leads of the Camp Century drilling expedition. He kept the ice core at a building on Ridge Lea Road in Amherst that housed UB’s Department of Geology while the North Campus was being built.
When retiring from UB in the 1990s, Langway gave the ice core to colleagues in Denmark. There it was lost for decades — until it was found again when the cores were being moved to a new freezer in 2017.
In 2019, Christ looked at the sediment through his microscope and found leaves and moss. That suggested that the area had been free of ice in the recent geologic past — and that a vegetated landscape stood where today stands an ice sheet two miles thick and three times the size of Texas.
Other scientists, working in central Greenland, have gathered data showing the ice there melted at least once in the last 1.1 million years — but no one knew exactly when.
Into the light
For this latest study, the team examined the Camp Century sediment for what is called a “luminescence signal.”
When bits of rock and sand are exposed to sunlight, any previous luminescence signal is zeroed out. When reburied in the darkness under rock or ice over time, minerals of quartz and feldspar in the sediment accumulate freed electrons in their crystals.
At the Utah State University lab of study co-author Tammy Rittenour, pieces of the ice core sediment were exposed to blue-green or infrared light, releasing the trapped electrons. The number of released electrons forms a kind of clock, revealing with precision the last time these sediments were exposed to the sun.
A sediment sample from the Camp Century core site. Credit: Drew Christ/University of Vermont
This powerful new data was combined with insight from Bierman’s University of Vermont lab, which studied the quartz from the Camp Century core. Ratios of beryllium and other isotopes inside the quartz – which build up when exposed to the sky and hit by cosmic rays — demonstrate how long rocks at the surface were exposed vs. buried under layers of ice.
This data helped the scientists show that, 400,000 years ago, the Camp Century sediment was exposed to the sky less than 14,000 years before it was deposited under the ice, narrowing down the time window when that portion of Greenland must have been ice-free.
Thomas conducted chemical analysis that enabled the team to understand the types of plants that were on site. The team is doing similar analyses to understand what the temperature and water cycle were like when those chemicals were produced.
Sea level
The team’s new study, combined with their earlier work, is causing a worrisome rethinking of the history of Greenland’s ice sheet and reveals its fragile nature today.
The last time the ice sheet melted, the team’s models show, it caused at least five feet of sea level rise. Temperatures during that time, an interglacial called Marine Isotope Stage 11, were similar to or slightly warmer than today, and atmospheric carbon dioxide was at least a third less than it is today.
“Forward modeling the rates of melt, and the response to high carbon dioxide, we are looking at meters of sea level rise, probably tens of meters,” Rittenour says. “And then look at the elevation of New York City, Boston, Miami, Amsterdam. Look at Bangladesh, India and Africa—most global population centers are near sea level.”
“Four-hundred-thousand years ago there were no cities on the coast,” Bierman adds, “and now there are cities on the coast.”
The research was supported by the National Science Foundation.
Media Contact Information
Tom Dinki News Content Manager Physical sciences, economic development
Tel: 716-645-4584 tfdinki@buffalo.edu
NAIROBI, Kenya (AP) — The body of Ugandan Olympic athlete Rebecca Cheptegei — who died after being set on fire by her partner in Kenya — was received Friday by family and anti-femicide crusaders, ahead of her burial a day later.
Cheptegei’s family met with dozens of activists Friday who had marched to the Moi Teaching and Referral Hospital’s morgue in the western city of Eldoret while chanting anti-femicide slogans.
She is the fourth female athlete to have been killed by her partner in Kenya in yet another case of gender-based violence in recent years.
Viola Cheptoo, the founder of Tirop Angels – an organization that was formed in honor of athlete Agnes Tirop, who was stabbed to death in 2021, said stakeholders need to ensure this is the last death of an athlete due to gender-based violence.
“We are here to say that enough is enough, we are tired of burying our sisters due to GBV,” she said.
It was a somber mood at the morgue as athletes and family members viewed Cheptegei’s body which sustained 80% of burns after she was doused with gasoline by her partner Dickson Ndiema. Ndiema sustained 30% burns on his body and later succumbed.
Ndiema and Cheptegei were said to have quarreled over a piece of land that the athlete bought in Kenya, according to a report filed by the local chief.
Cheptegei competed in the women’s marathon at the Paris Olympics less than a month before the attack. She finished in 44th place.
Cheptegei’s father, Joseph, said that the body will make a brief stop at their home in the Endebess area before proceeding to Bukwo in eastern Uganda for a night vigil and burial on Saturday.
“We are in the final part of giving my daughter the last respect,” a visibly distraught Joseph said.
He told reporters last week that Ndiema was stalking and threatening Cheptegei and the family had informed police.
Four in 10 women or an estimated 41% of dating or married Kenyan women have experienced physical or sexual violence perpetrated by their current or most recent partner, according to the Kenya Demographic and Health Survey 2022.
TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.
Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.
Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.
The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.
The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.
It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.
Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.
Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.
Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.
Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.
Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.
The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”
VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.
Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”
Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.
“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.
B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.
Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.
Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.
Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.
“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”
Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”
“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.
Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.
“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.
This report by The Canadian Press was first published Sept. 9, 2024.
