SEASCAPES-2023

The Southern California Bight (SCB) is the submerged region offshore California extending along the curved coastline from Point Conception to Cobo Colnett in Baja California, Mexico. Due to a complex tectonic combination of tension and extension, uplift and subsidence, the historic SCB was home to shallow productive marine basins that later created the rich, organic, source materials for the many tar balls and hydrocarbon seeps that dot the California Coastline and nearby islands. The fruitful marine ecosystems paired with abundant hydrocarbon seeps, contributed to this region’s noted early human habitation, where migrations of Pleistocene maritime hunter-gatherers likely remained in the area due to abundant marine mammal, fish, shellfish, and plant resources, tar resources, as well as easy access from the mainland to productive offshore islands (Gusick and Erlandson 2019). However, the SCB landscape experienced significant environmental shifts during the transition from the terminal Pleistocene to Late Holocene. Most notably, the region experienced a massive loss of subaerial land in the region due to inundation during the eustatic sea level rise that occurred approximately 20,000-8,000 years ago following the last glacial maximum (Clark et al. 2014). This transition from the Terminal Pleistocene to Early Holocene coincided with changes in climate further altering vegetation and animal diversity. There is ambiguity as to the timing and extent of extinction events and landscape evolution in the SCB. Therefore, the submerged portions of the landscapes extending offshore the regional continental shelf and islands in the SCB may provide crucial information on the evolution of landscapes, species extinctions and arrivals, and introduction of humans into this rapidly changing environment. The modern-day SCB has grown to be a densely populated region where people continue to influence and interact with both migratory and resident animal populations as well as disturb previous human settlements. To preserve and understand these vulnerable ecosystems and cultural heritage sites, baseline data must be assembled. These data will be collected over two multidiscplinary projects using remote sensing and sampling techniques more traditionally used for geological studies. Our goal is to use the rock record and sediment character to establish a baseline for paleolandscapes and biodiversity within the SCB. We believe that by focusing on defining the SCB on a variety of temporal scales with regards to human settlement and activity, we can not only provide data germane to geological and paleontological disciplines, but also narrow search parameters to identify archaeological “hot spots” on the continental shelf. This will be a joint effort between students and experts from many disciplines and institutions to collect data that bolsters our ability to investigate sensitive cultural landscapes and to eventually to document and preserve marine flora, fauna, and cultural heritage resources.