ABSTRACT

ABSTRACT: On February 17, 2006, a large-scale rockslide occurred in Southern Leyte Province, Philippines following days of heavy rainfall. This rockslide, considered to be one of the largest to have occurred in the last few decades, buried almost the entire village of Ginsaugon and caused the death of more than 1300 people. The landslide, which occurred along the steep slope of Mt. Can-abag in the middle part of the province, mobilized large amount of rocks and debris with estimated volume of about 20-25 million m3 and a runout distance of almost 4 km. Heavy rainfall before the landslide, including a 688 mm rainfall intensity during the 9-day period prior to the slide which is equivalent to 2.5 times the mean rainfall amount for the whole month of February, must have played a major role on the instability of the slope. Minor earthquakes, the strongest of which had a surface-wave magnitude of Ms = 2.6 and whose epicenter was determined to be 23 km west of the landslide site, were reported to have occurred prior to or right after the slide. It is not clear whether these earthquakes played a role in the triggering of the landslide or whether the landslide generated this ground tremors. This paper summarizes the main characteristics of the landslide, discusses its geological, tectonic and climatic setting and looks into possible mechanism and trigger of the landslide.