USask assistant professor Colin Sproat stands by a wall of a quarry north of The Pas, Manitoba, one of the sites where the researchers found evidence of an ancient tsunami. Credit: Brian Pratt
Hundreds of millions of years ago, an earthquake sent a series of massive waves across the ancient sea that covered part of Western Canada and the northern United States.
That is the conclusion of a new paper by two University of Saskatchewan (USask) researchers, who have found the strongest-ever evidence of a tsunami in a shallow inland sea.
The research by Dr. Brian Pratt (Ph.D.) and Dr. Colin Sproat (Ph.D.) of USask’s College of Arts and Science is published in Sedimentary Geology.
Saskatchewan and its neighboring areas are not known for their coastal views—or for their seismic activity. But 445 million years ago, in the period called the Ordovician, the region looked very different. Much of what is now Saskatchewan and Manitoba in Canada, along with Montana and the Dakotas in the U.S., was covered by a sea known as the Williston Basin.
“It was a completely different environment, completely different geography. Back then, we were much closer to the equator than we are today and the sea level was high, so we would have been in a tropical, shallow inland sea rather than a temperate grassland like today,” said Sproat, an assistant professor in the USask Department of Geological Sciences.
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Pratt and Sproat visited three sites north of The Pas, Manitoba, where they found evidence of a short, high-energy event in this ancient sea, which had gone unnoticed by geologists until now.
Certain beds of sediment at the locations had been torn into pebbles and mixed with clay. The floor beneath the deeper waters of the basin contained no clay, so it could only have come from the land.
“We realized we needed an event that rips up the sea bottom and then somehow comes back again with all this clay, and does it a few times,” said Pratt, a professor in the Department of Geological Sciences.
The answer could only be a tsunami. No animal life and almost no plant life existed on land to witness that day nearly half a billion years ago, but if an observer had been around, they would have seen a dramatic event.
Faults in the region’s crust, quiet now for thousands of millennia, were then still active. One of these faults somewhere in the northern half of the Williston Basin suddenly slipped, sending violent shockwaves through the sea.
The water at the shore would have briefly dropped, then rushed back in a relentless surge. The wave might have pushed a kilometer or more across the gently sloping land, scouring the rocky surface. When it finally receded, it washed clay back into the sea. More waves followed.
A tsunami is a “radical interpretation” of the evidence, acknowledges Pratt, but the USask researchers had an advantage. The strata of the Williston Basin in Canada are almost entirely hidden under Manitoba’s and Saskatchewan’s flat landscapes, which limited past geologists to studying only a few natural outcrops, core samples and roadway cuts.
An outline of the Williston Basin in the Late Ordovician period. Credit: Brian Pratt / Colin Sproat
In the last decade, several new quarries have been dug in Northern Manitoba and revealed more of the basin’s secrets.
“It was checking out the quarries that opened our eyes. We go into these quarries and we can see the layering extending laterally for 100 meters or more, and we can find the same bed in more than one place. And so that gave us sort of the 3D perspective that nobody had before,” said Pratt.
Similar deposits can be made by major storms, but Sproat and Pratt ruled out a storm as the cause due to a lack of other telltale signs of regular storm activity. Furthermore, the region was too close to the ancient equator to have experienced hurricanes.
The new paper gives a clearer picture of the forces that shaped an environment lost to history: one in which early marine life flourished and diversified.
“The Williston Basin was covered by this really unusual sea on top of the continent, an environment we don’t have a good modern analog for. Given that, we have a unique opportunity here to study geological processes and their impact on ancient ecosystems in a setting unlike anywhere on the planet today,” said Sproat.
The USask researchers plan to visit sites elsewhere in Canada to see if other beds show overlooked evidence of seismic sea waves—and whether tsunamis might have been a bigger part of Earth’s history than is commonly believed.
“It’s a subject you won’t find in the geology textbooks,” said Pratt. “I think it’s time for a paradigm shift.”
More information:
Brian R. Pratt et al, A tsunami deposit in the Stonewall Formation (Upper Ordovician), northeastern margin of the Williston Basin, Canada, and its tectonic and stratigraphic implications, Sedimentary Geology (2023). DOI: 10.1016/j.sedgeo.2023.106518
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.
