Recent deep-seated coastal landsliding at San Onofre State Beach, California

摘要: Abstract Airborne LiDAR collected during the period 1998–2010 and differential GPS surveys conducted over 2008–2013 show recent reactivation movement of a large deep-seated coastal landslide at San Onofre State Beach, Diego County, California. The overall slide complex extends about 700 m alongshore, 150 m inland, an unknown distance offshore. Differencing digital elevation models tracking field monuments (benchmarks) provide time series quantitative topographic changes new insight in to motion sequences mechanics. contains several distinct primary secondary regions moving deforming different rates. Primary includes slow seaward translational motion, rotational slipping, upward offshore movement. Secondary processes basal wave erosion inland cliffline failures contribute destabilization. exhibits lithologic structural controls, is driven by combination marine subaerial processes, influences local beach morphology, deviates from typical southern California cliff which mostly involve shallow landslides topples. Large-scale, cross-shore rotation has recently created nearshore reefs. Eroded sediments sand source probably influence ecosystems. All known periods major historical activity were preceded elevated seasonal rainfall analysis suggests generated as opposed action. As spring 2013, slowed, but continued positive feedbacks including toe removal suggest that future landsliding will threaten infrastructure.