| The Abalone Cove landslide occupies 80 acres of an ancient landslide complex on the Palos Verdes peninsula. The influx of water into the slide mass is a short-term catalyst for movement. The objective of this study is to constrain the sources and flow rates of water entering and adjacent to the landslide complex.; MODPATH modeling indicates that water flows through the ancient landslide complex in 22--28 years. MODFLOW models and measurements of hydrologic tracers, CFC-12 and tritium, demonstrate that most of the water in the complex is recent precipitation falling within the basin. The uphill groundwater basin contributes minor flow to the ancient complex, with the majority of its water flowing beneath the ancient slide plane. However, some communication between the shallow and deep aquifers must occur. The deep circulating water may exert a strong hydraulic pressure on the landslide slip surface, increasing the potential for movement. |
