Our Submerged Past: Exploring Inundated Late Pleistocene (10,600 - 17,000 years ago) Caves in Southeast Alaska with Sunfish
May 15-June 4, 2022 / May 24-June 10, 2023
Our Submerged Past 2023 Field Summary
From May 25 through June 10, our team of Indigenous Alaskans, local community members, and scientists explored and sampled the continental shelf west of Prince of Wales Island in southeast Alaska. The SUNFISH® autonomous underwater vehicle completed 33 dives, surveying, 3D mapping, sampling sediment, and guiding our dive team to retrieve sample cores, which are currently undergoing analysis.
We struggled with some of the worst weather Captain Roby Medina has seen in years, including small craft advisories for 10 of the 15 days of the deployment. As a result, we were unable to return all of the targets identified in the 2022 survey. However, field operations manager Vickie Siegel and field and robotics technician Mimi Alexander wrangled SUNFISH in all conditions, so that despite the limitations, it was able to complete full, high-resolution, 3D surveys at 22 different locations, covering 640,00 square meters (0.25 miles).
Robotics principal investigator Kristof Richmond and robotic software engineer Tyler Haden guided SUNFISH to explore Sea Lion Cave, bringing back high-resolution 3D sonar maps and a sediment sample. In addition, SUNFISH-generated maps of two other rockshelters or overhangs were used to physically lead our divers, Jason Gulley and Tamara Adame, to locations selected by science principal investigator Kelly Monteleone to retrieve larger sample cores using a two-inch PVC pipe. All of these sediment samples were processed in the field with the help of intern Taylor Heaton and have been sent out for pollen, dinoflagellete cyst, microdebitage, and radiocarbon analysis.
We are now reviewing and comparing the side-scan sonar data from 2022 and the multibeam sonar data collected by SUNFISH this year. The combined sonar data set will further our understanding of the locations identified in the 2022 data and, combined with the diver samples and SUNFISH’s camera, give us a clear picture of these seafloor features.
By Kristof Richmond, Our Submerged Past Principal Investigator; CTO, Sunfish, Inc.
Published July 26, 2023