Affiliation: | aInstitut de Physique du Globe, UMR 7516, 5 rue René Descartes, 67084 Strasbourg, France bDepartment of Environmental and Applied Geology, University of Jordan, Amman 11942, Jordan cDepartment of Earth and Environmental Sciences, The Hachemite University, P.O. Box 150459, Zarqa 13115, Jordan dAl-Balqa Applied University, Royal Jordanian Geographic Centre College for Survey Sciences, P.O. Box 414, Al-Jubaiha 11941, Jordan eNatural Resources Authority, P.O. Box 7, Amman 11118, Jordan |
Abstract: | ![]() We investigate the late Quaternary active deformation along the Jordan Valley segment of the left-lateral Dead Sea Fault and provide new insights on the behaviour of major continental faults. The 110-km-long fault segment shows systematic offsets of drainage systems surveyed at three sites along its southern section. The isotopic dating of six paleoclimatic events yields a precise chronology for the onset of six generations of gully incisions at 47.5 ka BP, 37.5 ka BP, 13 ka BP, 9 ka BP, 7 ka BP, and 5 ka BP. Additionally, detailed mapping and reconstructions provide cumulative displacements for 20 dated incisions along the fault trace. The individual amounts of cumulative slip consistently fall into six distinct classes. This yields: i) an average constant slip rate of 4.7 to 5.1 mm/yr for the last 47.5 kyr and ii) a variable slip rate ranging from 3.5 mm/yr to 11 mm/yr over 2-kyr- to 24-kyr-long intervals. Taking into account that the last large earthquake occurred in AD 1033, we infer 3.5 to 5 m of present-day slip deficit which corresponds to a Mw 7.4 earthquake along the Jordan Valley fault segment. The timing of cumulative offsets reveals slip rate variations critical to our understanding of the slip deficit and seismic cycle along major continental faults. |