Amy Gusick, Expedition Co-Principal Investigator (with Jillian Maloney) - Associate Curator of Archaeology, Natural History Museum Los Angeles County
September 25 - October 5, 2021
From September 25 - October 5, 2021, the project team will conduct geophysical surveys aboard the Scripps Institution of Oceanography Research Vessel Bob and Betty Beyster, focusing on regions of the eastern Pacific continental shelf that contain tar seeps, paleochannel, and possible paleoestuaries.
The southern California region has a high density of subaerial (above sea level) cultural sites associated with terminal Pleistocene and early Holocene human occupation (15,000-8,000 years ago). During these same time periods, post-glacial sea level rise submerged thousands of square kilometers of coastal land, shifting shorelines inland and reducing the subaerial landscape of offshore islands. These facts suggest that archaeological deposits are likely located on these submerged landscapes of the Pacific Coast and present the opportunity to contribute to answering one of the most significant archaeological questions of our time: how and when humans entered the Americas.
However, before we can address this question, we need to understand what the paleolandscape and paleoenvironment was like when humans first entered this region. Recent research on the submerged paleolandscape of Southern California suggests that features such as paleochannels, paleoestuaries, and offshore tar seeps – all features used by Native American communities during the terminal Pleistocene and Holocene along the Pacific Coast – can be identified and used to model sensitive archaeological and biological landscapes. These features can provide data to enhance understanding of the local paleoecology and paleolandscape evolution, a crucial first step in our ability to eventually identify, document, and preserve underwater cultural heritage resources and maritime cultural landscapes.
Our team of archaeologists, paleontologists, marine geologists, and geophysicists are building on previous research by mapping, studying, and sampling late Pleistocene landforms and environmental features from the submerged landscapes of the Southern California Bight.
The expedition team will conduct geophysical surveys that will include chirp subbottom and controlled source electromagnetic technology (CSEM). The CSEM is not commonly used in underwater archaeological surveys; however, CSEM measures the apparent resistivity of submerged features independent of those detected by acoustic methods and provides a separate data set to consider for mapping of specific features and more targeted sampling.
The acoustic and CSEM data can be used to consider a range of studies including tectonic activity, sea-level rise, habitat and biodiversity shifts, marine sedimentation rates, and landscape changes such as paleochannel and watershed evolution. Understanding shifts in paleolandscapes and paleoecology over time is critical for understanding how humans interacted with these ecosystems and for identifying regions sensitive for cultural evidence of habitation and habitat use. Signatures in the geophysical data consistent with tar seeps and possible terrestrial deposits will be the focus of a 2022 research cruise in which the project team will use a SubAtlantic Mohawk 18 remotely operated vehicle to selectively image and sample targets.
This project on the submerged landscapes in the Southern California Bight is on the traditional territory of the Chumash Tribe. An important aspect of this project is inclusion of the tribe as well as two members of the Santa Ynez Band of Chumash Indians, who have joined the team as interns.
NOAA Ocean Exploration provided funding for this expedition via its 2020 Federal Funding Opportunity for Ocean Exploration.
Published September 20, 2021