Quantitative Risk Analysis of Earthquake-Induced Landslides

Abstract

Quantitative risk analysis is valuable tool in risk management, yet the calculation of risk is often hampered by a lack of quality spatial input data, particularly landslide event inventories. These event inventories provide information to determine the number, size and spatial location of landslides triggered by discrete events such rainfall or earthquakes. This paper presents an approach whereby we use historical New Zealand earthquake-induced landslide inventories to estimate the landslide hazard for the Franz Josef and Fox glacier valleys, West Coast, South Island, New Zealand, as no pre-existing complete earthquake-induced landslide inventories exist for this area of New Zealand. We outline a methodology for the calculation of earthquake-induced landslide magnitude-frequency relationships from the 2016 Mw 7.8 Kaikōura earthquake, the 1968 Mw 7.1 Inangahua earthquake, and the 1929 Mw 7.8 Murchison earthquake to determine the probability of a given volume of landslide occurring for different levels of ground shaking.KeywordsEarthquake-induced landslidesMagnitude—frequency analysisQuantitative risk analysis