RAPID: Exploiting El Nino to Test for Shear Dilation in a Slow Moving Landslide

University Of California-Santa Cruz, Santa Cruz CA

Investigators

Abstract

Landslides are a natural hazard that can potentially damage infrastructure and cause loss of life. Some landslides are rapid and catastrophic, occurring over periods of seconds to minutes. Others are sluggish, sometimes moving only millimeters per year and only when activated by rain. Over years to centuries, these slow-moving landslides, also known as earthflows, can contaminate waterbodies with sediment and damage dams and other types of civil infrastructure. This project will examine a long dormant earthflow in California that is expected to move this winter as a result of the coming El Nino that meteorologists are predicting. The data collected may lead in the future to the ability to predict the conditions that result in earthflow movement. This knowledge could be useful for construction and management of civil infrastructure. In addition, this project will provide training to a Native American Ph.D. student. The project results will be shared with a public utility commission to inform their management decisions. This project will use new measurements from a continuous Ground-Penetrating Radar (GPS) station and a shallow groundwater monitoring network in combination with an existing network of 40 established benchmarks on the Oakridge earthflow near San Jose, CA, to test the Principal Investigator's hypothesis for the physical process that regulates the deformation of earthflows and prevents them from failing catastrophically. The proposal addresses the lack of transport laws for predicting landslide motion, identified as a key knowledge gap in the 2010 National Research Council report "Landscapes on the Edge". Given the possibility that the coming El Nino event may be among the strongest ever recorded, this project offers a unique, time-sensitive opportunity to examine widespread landslide activity.