Call for Registration
Arctic Research Seminar Series
Arctic Research Consortium of the U.S. (ARCUS)
Date/Time: Wednesday, 5 October 2022, 9:00 a.m. Alaska Time
Speaker: Charlie Paull, Monterey Bay Aquarium Research Institute (MBARI)
Presentation Title: Decomposing Submarine Permafrost in the Canadian Beaufort Sea
To register for the event, go to:
https://www.arcus.org/research-seminar-series
The Arctic Research Consortium of the U.S. (ARCUS) invites registration for the next Arctic Research Seminar featuring Charlie Paull, Senior Scientist at the Monterey Bay Aquarium Research Institute (MBARI). Charlie’s presentation, titled Decomposing Submarine Permafrost in the Canadian Beaufort Sea, will be held via Zoom on Wednesday, 5 October 2022 at 9:00 a.m. AKDT (1:00 p.m. EDT).
Seminar Abstract:
Sediments beneath the Arctic continental shelf are undergoing substantial warming. This warming is associated with the sea level transgression at the end of the last ice age, when relatively warm ocean water flooded over a much colder terrestrial periglacial landscape. The warming is still propagating down into subsurface sediments causing the glacial-aged permafrost wedge to thin and retreat landwards. Models of the impact of transgression on subsea permafrost have recognized the potential existence of a slowly moving groundwater system that carries waters seaward under the extensive glacial-age relict permafrost bodies hosted within shelf sediments. Pore waters sampled in 50 sediment cores taken from 90 to 1000 m water depths along the shelf edge and upper slope of the Canadian Beaufort Sea freshen with sub-bottom depth, suggesting near-seafloor sediments are pervasively bathed in brackish water. Their isotopic composition suggests relict permafrost is the source for the freshening waters along the shelf edge. High-resolution bathymetric surveys of the shelf edge of the Canadian Beaufort Sea reveal a remarkable coalescence of seafloor morphologic features (e.g., slump-scars, submarine-pingos, and steep-sided closed depressions) in the areas where these waters are emerging. Repeat mapping also shows multiple new steep-sided depressions that developed in the 9-year-long interval between surveys. The largest is 28 m in depth and 220 m across. These morphological changes occur near the maximum seaward limit of the submerged glacial-age permafrost and are attributed to groundwater flow, ascending along the relict permafrost boundaries and inducing segregated ice in relict permafrost to melt.
Registration is required for this event. Instructions for accessing the webinar will be sent to registrants prior to the event.
To register for the event, go to:
https://www.arcus.org/research-seminar-series
For questions, contact:
Stacey Stoudt
Email: stacey [at] arcus.org