The Arctic seafloor is a dynamic and complex environment, as revealed by recent research conducted by an international team of scientists. Led by the Monterey Bay Aquarium Research Institute (MBARI), the team discovered massive craters and large mounds on the seafloor at the edge of the Canadian Beaufort Sea. These formations, some larger than football fields, were initially thought to be the result of ancient permafrost melting beneath the waves.
However, the team’s latest findings suggest that the ice formations are actively forming and decomposing under present-day conditions. Using underwater robots, the researchers collected samples from within the newly-formed seafloor craters. Analysis of these samples revealed that the ice was created when deeper layers of ancient permafrost melted under the sea, producing brackish groundwater that then refroze on the seafloor.
“These findings upend our assumptions about underwater permafrost,” said Charlie Paull, the study’s lead author from MBARI.
Underwater permafrost dynamics illuminated
“We previously believed all underwater permafrost was leftover from the last ice age, but we’ve learned that submarine permafrost ice is also actively forming and decomposing on the modern seafloor.”
The groundwater remains frozen at temperatures of -1.4°C (29.5°F), and the process continues in a dynamic cycle.
This creates a complex underwater landscape marked by massive sinkholes and large mounds of ice covered in sediment. The team’s findings, published in the Journal of Geophysical Research: Earth Surface, highlight the intricate processes at play beneath the Arctic waters. Collaborators from institutions such as the Korea Polar Research Institute (KOPRI) and the Geological Survey of Canada contributed to the study.
Ongoing research, which began with a Canadian survey in 2010 and continued with MBARI’s high-resolution mapping surveys, has mapped over 65 newly-formed craters on the seafloor. The largest of these craters spans the size of a city block of six-story buildings. This groundbreaking discovery provides new insights into the complex and dynamic nature of underwater permafrost, reshaping our understanding of the Arctic seafloor.
The findings have significant implications for policymakers making decisions about underwater infrastructure in the Arctic.
Noah Nguyen is a multi-talented developer who brings a unique perspective to his craft. Initially a creative writing professor, he turned to Dev work for the ability to work remotely. He now lives in Seattle, spending time hiking and drinking craft beer with his fiancee.
