Intermittent surging movements of a coastal landslide

Autor: P. Grainger, P. G. Kalaugher
Rok vydání: 1987
Předmět:
Zdroj: Earth Surface Processes and Landforms. 12:597-603
ISSN: 1096-9837
0197-9337
DOI: 10.1002/esp.3290120603
Popis: Since the late 1960s there has been a large mudslide in coastal cliffs of Permo-Triassic strata (conglomerate overlying mudstone) at West Down Beacon, 2 km west of Budleigh Salterton, Devon. A total displacement of 100 m was achieved between 1981 and 1985 as the lobate toe of the mudslide pushed forward across the beach in eleven surges of movement. Each surge involved a displacement of between 5 and 15 m and was completed within a few hours. The toe moved by planar sliding, possibly on more than one seaward-dipping shear surface or zone. Occasionally there were additional relatively minor displacements (less than 1 m), but normally the mudslide was stationary between the major surges. After each surge high-oblique aerial photographs were obtained for stereoscopic interpretation. Debris falls from the cliff appear to have triggered some of the mudslide surges. A displacement recording of one surge has indicated that the rate of movement of the mudslide may have been partly controlled by variations in sea level during the tidal cycle.
Databáze: OpenAIRE
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