Geophysics professor ends his journey to explore the origin of the Amerasia Basin



It takes more than an hour for a seabed seismometer to rise from the seabed to the surface. The aircraft was fitted with a piece of nylon rope, which the crew grabbed with a grapple. Image-Bernard Coakley.

A science cruise led by a researcher from the University of Alaska at Fairbanks to investigate the origin of the Amerasia Basin in the Arctic Ocean has come to an end, with the research vessel Sikuliaq returning to Nome after more than seven weeks in sea.

The trip was the northernmost of Sikuliaq to date. He sailed just over 79 degrees 39 minutes north latitude in the Arctic Ocean, about 500 miles north of Utqiaġvik on the Alaskan coast.

Bernard Coakley, professor of geophysics at the UAF Geophysical Institute, the project’s principal investigator, said in one of his latest daily email updates that the cruise presents some challenges.

“We had to fight against the ice. I think we managed, despite this struggle, to make good use of the ship‘s time and collect data of unique value, ”he wrote on Sunday September 26th. “We only looked at very preliminary plots of the seismic reflection, ocean- the bottom seismometer and sonobuoy data that we collected in class, but the data appears to be very good, clearly imaging the sediments and structures. underlying.

“Over the next few years, we will process this data to improve the deeper features of the sedimentary section and learn more about the history of Borderland and the Canada Basin,” he wrote. “I can not wait to be there.”

The map shows the trajectory of the research vessel Sikuliaq in the Arctic Ocean.  Image-Bernard Coakley
The map shows the trajectory of the research vessel Sikuliaq in the Arctic Ocean. Image-Bernard Coakley

Coakley, the rest of the science team, and the crew departed Seward on August 10 in an effort to explain the formation of the Amerasia Basin, one of the two major basins in the Arctic Ocean.

The National Science Foundation, which funded the research, owns Sikuliaq. The vessel, which is part of the US university research fleet, is operated by the UAF College of Fisheries and Ocean Sciences.

The plan called for mapping the northern edge of the Chukchi Basin’s border as well as the adjacent Canada Basin, a component of the Amerasia Basin that lies north of Alaska and Canada.

They collected multichannel seismic reflection data to gain insight into the stratification and structure of the crust to reveal the history of the basin. They also collected seismic refraction data using ocean floor seismometers and sonobuoys, typically used for hunting submarines.

Coakley, in his update on Monday, September 27, said he was surprised at the extent of the ice.

“The ice was not much by historical standards, but it was surprising compared to the recent constant degradation of the pack ice, both in thickness and extent,” he wrote. “The ice edge this year is well south of recent years, although a large gap is observed in the central Canada Basin. While it looks like we can anticipate the continued sea ice retreat, we may not be able to predict where it will retreat in any given year.

In his latest daily report, sent last Wednesday evening, Coakley described life on the remote research vessel.

“I like to say that every cruise is a psychological experience. We don’t anticipate this aspect of science, but it happens every time you get a group of people together to do certain tasks in isolation under sometimes stressful circumstances, ”he wrote.

“Of course there is friction and frustration, but in the end we have been successful both scientifically and socially.”

He also included in this final report, as he did with each daily update, a report on the animals observed. The tally in Wednesday’s update: seven walruses swimming together and 15 gray whales in a group. On Tuesday, they saw a walrus, two bearded seals and an unidentified seal.

Source: Institute of Geophysics



Leave A Reply