TY - JOUR
T1 - Large landslides associated with a diapiric fold in Canelles Reservoir (Spanish Pyrenees): Detailed geological-geomorphological mapping, trenching and electrical resistivity imaging
AU - Gutiérrez, Francisco
AU - Linares, Rogelio
AU - Roqué, Carles
AU - Zarroca, Mario
AU - Carbonel, Domingo
AU - Rosell, Joan
AU - Gutiérrez, Mateo
PY - 2015/7/5
Y1 - 2015/7/5
N2 - © 2015 Elsevier B.V. Detailed geomorphological-geological mapping in Canelles Reservoir, the Spanish Pyrenees, reveals the presence of several large landslides overlooked in previous cartographic works. One of the slope movements, designated as the Canelles landslide, corresponds to a 40×106m3 translational landslide reactivated in 2006 by a severe decline in the reservoir water level. The geomorphic features mapped in the upper part of the Canelles landslide, including surface ruptures corroborated by electrical resistivity imaging and trenching, indicate multiple displacement episodes previous to the 2006 human-induced event. Consistently, the stratigraphic and structural relationships observed in a trench record at least two displacement events older and larger in magnitude than the 2006 reactivation. The oldest recorded event occurred in the 6th to 7th Centuries and the second in 1262-1679yrAD. This latter episode might be correlative to the 1373 Ribagorza earthquake (Mw 6.2), which caused the reactivation of a landslide and the consequent destruction of a village in the adjacent valley. The available data indicate that over more than one millennium the kinematics of the landslide has been characterised by discrete small-displacement episodes. These data, together with the available literature on rapid rockslides, do not concur with the acceleration predicted by modelling in a previous investigation, which foresees a speed of 16ms-1 despite the low average dip of the sliding surface (9-10°). This case study illustrates that the trenching technique may provide valuable practical information on the past behaviour of landslides, covering a much broader time span than instrumental and historical records.
AB - © 2015 Elsevier B.V. Detailed geomorphological-geological mapping in Canelles Reservoir, the Spanish Pyrenees, reveals the presence of several large landslides overlooked in previous cartographic works. One of the slope movements, designated as the Canelles landslide, corresponds to a 40×106m3 translational landslide reactivated in 2006 by a severe decline in the reservoir water level. The geomorphic features mapped in the upper part of the Canelles landslide, including surface ruptures corroborated by electrical resistivity imaging and trenching, indicate multiple displacement episodes previous to the 2006 human-induced event. Consistently, the stratigraphic and structural relationships observed in a trench record at least two displacement events older and larger in magnitude than the 2006 reactivation. The oldest recorded event occurred in the 6th to 7th Centuries and the second in 1262-1679yrAD. This latter episode might be correlative to the 1373 Ribagorza earthquake (Mw 6.2), which caused the reactivation of a landslide and the consequent destruction of a village in the adjacent valley. The available data indicate that over more than one millennium the kinematics of the landslide has been characterised by discrete small-displacement episodes. These data, together with the available literature on rapid rockslides, do not concur with the acceleration predicted by modelling in a previous investigation, which foresees a speed of 16ms-1 despite the low average dip of the sliding surface (9-10°). This case study illustrates that the trenching technique may provide valuable practical information on the past behaviour of landslides, covering a much broader time span than instrumental and historical records.
KW - Geophysics
KW - Impulse water wave
KW - Rapid landslides
KW - Reservoir
KW - Retrodeformation analysis
U2 - 10.1016/j.geomorph.2015.04.016
DO - 10.1016/j.geomorph.2015.04.016
M3 - Article
SN - 0169-555X
VL - 241
SP - 224
EP - 242
JO - Geomorphology
JF - Geomorphology
ER -