TY - JOUR
T1 - Soft sediment deformation by Kelvin Helmholtz Instability
T2 - A case from Dead Sea earthquakes
AU - Heifetz, Eyal
AU - Agnon, Amotz
AU - Marco, Shmuel
N1 - Funding Information:
We thank Beny Begin for a constructive review. A. Agnon thanks the German–Israel Binational Science Foundation (GIF) for support. S. Marco was supported by an Israel–US Binational Science Foundation grant #286/97.
PY - 2005/7/30
Y1 - 2005/7/30
N2 - The standard explanation for soft sediment deformation is associated with overturn of inverted density gradients. However, in many cases, observations do not support this interpretation. Here we suggest an alternative in which stably stratified layers undergo a shear instability during relative sliding via the Kelvin-Helmholtz Instability (KHI) mechanism, triggered by earthquake shaking. Dead Sea sediments have long stood out as a classical and photogenic example for recumbent folding of soft sediment. These billow-like folds are strikingly similar to KHI structures and have been convincingly tied to earthquakes. Our analysis suggests a threshold for ground acceleration increasing with the thickness of the folded layers. The maximum thickness of folded layers (order of decimeters) corresponds to ground accelerations of up to 1 g. Such an acceleration occurs during large earthquakes, recurring in the Dead Sea.
AB - The standard explanation for soft sediment deformation is associated with overturn of inverted density gradients. However, in many cases, observations do not support this interpretation. Here we suggest an alternative in which stably stratified layers undergo a shear instability during relative sliding via the Kelvin-Helmholtz Instability (KHI) mechanism, triggered by earthquake shaking. Dead Sea sediments have long stood out as a classical and photogenic example for recumbent folding of soft sediment. These billow-like folds are strikingly similar to KHI structures and have been convincingly tied to earthquakes. Our analysis suggests a threshold for ground acceleration increasing with the thickness of the folded layers. The maximum thickness of folded layers (order of decimeters) corresponds to ground accelerations of up to 1 g. Such an acceleration occurs during large earthquakes, recurring in the Dead Sea.
KW - Dead Sea basin
KW - Kelvin-Helmholtz Instability
KW - Paleo-earthquake intensity
KW - Soft sediment deformation
UR - http://www.scopus.com/inward/record.url?scp=22144472201&partnerID=8YFLogxK
U2 - 10.1016/j.epsl.2005.04.019
DO - 10.1016/j.epsl.2005.04.019
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AN - SCOPUS:22144472201
SN - 0012-821X
VL - 236
SP - 497
EP - 504
JO - Earth and Planetary Science Letters
JF - Earth and Planetary Science Letters
IS - 1-2
ER -