A new study led by MBARI experts and colleagues is the first to show how the melting of permafrost, which is buried underwater at the Arctic Ocean’s edge, is changing the seabed. On March 14, 2022, the work was published in the Proceedings of the National Academy of Sciences.
Numerous peer-reviewed research reveal that melting permafrost generates unstable terrain, which has a severe effect on critical Arctic infrastructure including roads, railway lines, buildings, and airports. This infrastructure is costly to restore, and the consequences and costs are anticipated to worsen.
MBARI researchers and partners discovered substantial changes to the seabed as a consequence of melting permafrost using modern underwater imaging technologies. Deep sinkholes have developed in certain regions, some bigger than a city block of six-story buildings. Pingos, or ice-filled hills, have emerged from the bottom in various regions.
“We know that large changes are occurring over the Arctic region, but this is the first time we’ve been able to deploy equipment to show that changes are occurring offshore as well,” said Charlie Paull, a geologist at MBARI and one of the study’s primary authors. “This ground-breaking study has shown how to identify and monitor the melting of undersea permafrost after baselines are established.”
While human-caused climate change has contributed to the degradation of terrestrial Arctic permafrost, the changes the research team has documented on the seafloor associated with submarine permafrost are the result of much older, slower climatic shifts associated with our emergence from the last ice age. For thousands of years, similar changes seem to have occurred at the seaward border of the old permafrost.
“There isn’t much long-term data for seafloor temperature in this region, but what we do have doesn’t show a warming trend. Instead, heat delivered in slowly flowing groundwater systems drives changes in seabed landscape “Paull explained.
“This research was made possible by international collaboration over the last decade, which has provided access to modern marine research platforms such as MBARI’s autonomous robotic technology and icebreakers operated by the Canadian Coast Guard and the Korean Polar Research Institute,” said Scott Dallimore, a research scientist with Natural Resources Canada’s Geological Survey who led the study with Paull. “The Government of Canada and the Inuvialuit people who live on the Beaufort Sea coast place a high importance on this study since the complex processes described have consequences for geohazard assessment, the establishment of unique marine habitat, and our knowledge of biogeochemical processes.”
The Canadian Beaufort Sea, a remote section of the Arctic, has only lately become accessible to scientists as sea ice retreats due to climate change.
MBARI has been collaborating with the Geological Survey of Canada, the Department of Fisheries and Oceans Canada, and, since 2013, the Korean Polar Research Institute to explore the seabed of the Canadian Beaufort Sea.
MBARI employed autonomous underwater vehicles (AUVs) and ship-based sonar to map the bathymetry of the seabed to a one-meter square grid resolution, or approximately the size of a dining table.
This summer, Paull and his colleagues will return to the Arctic aboard the R/V Araon, a Korean icebreaker. This journey alongside MBARI’s long-time Canadian and Korean colleagues, as well as the inclusion of the US Naval Research Laboratory, will help us deepen our knowledge of undersea permafrost deterioration.
Two MBARI AUVs will map the seabed in incredible detail, and MBARI’s MiniROV – a portable remotely operated vehicle – will allow for further exploration and sampling to supplement the mapping studies.
The David and Lucile Packard Foundation, the Geological Survey of Canada, Fisheries and Oceans Canada, and the Korean Ministry of Oceans and Fisheries all contributed to this research (KIMST grant No. 1525011795).