Abstract

Landslides caused by earthquakes have been extensively studied in different parts of the world, in different geodynamic settings. In our case, the February 27, 2010, an Mw 8.8 megathrust earthquake severely hits the coasts of south-central Chile, with a rupture zone of more than 450 km. long producing landslides along the coastal range and coastal plains between the cities of Valparaiso and Valdivia. The area most affected by landslides was the Arauco Peninsula. An inventory of the events based on satellite images and field work was performed. 126 landslides were inventoried/detected, including rock slides, soil slides, rockfalls and rock avalanches. The landslides are concentrated near the towns of Punta Lavapie and Tubul in soft sedimentary units, with mainly sandstones and limestones, suggesting a lithologic control. In the field campaigns two major rock slides were selected to perform a reconstruction of the slopes and stability analysis to determine which factors led to failure. Ongoing laboratory tests and topographic models from photogrammetry and laser scanning techniques are carried out in order to obtain geotechnical and geometrical parameters for numerical modelling.