|
Article |
Department of Geology, The University of Portsmouth, , The Burnaby Building, Burnaby Road, Portsmouth PO1 3QL, UK
Investigation of landslides which have been located from contemporary accounts of the Straits of Messina earthquake of 1908 reveals that a failure envelope for the slopes may be drawn on the basis of slope height-slope angle relationships for static and dynamnic stresses. As would be expected there is a decrease in stability during the earthquake to a degree which is almost certainly linked to the generation of pore water pressures. However, a region of the failure envelope shows much greater decrease in stability; this section of the curve describes the stability of low slope height-high slope angle forms. The area for which this stability curve has been calculated is affected by a nearfield earthquake. It is suggested that these slopes are suffering from forced vibration from high-frequency accelerations. In support of such a hypothesis of a geomorphological control is the observations that many of the landslides along this section of coastline occurred at topographic irregularities.