Long-term earthquake clustering: A 50,000-year paleoseismic record in the Dead Sea Graben

Shmuel Marco*, Mordechai Stein, Amotz Agnon, Hagai Ron

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

320 Scopus citations

Abstract

The temporal distribution of earthquakes in the Dead Sea Graben is studied through a 50,000-year paleoseismic record recovered in laminated sediments of the Late Pleistocene Lake Lisan (paleo-Dead Sea). The Lisan represents more than 10 times the 4000 years of historical earthquake records. It is the longest and most complete paleoseismic record along the Dead Sea Transform and possibly the longest continuous record on Earth. It includes unique exposures of seismite beds (earthquake-induced structures) associated with sup events on syndepositional faults. The seismites are layers consisting of mixtures of fragmented and pulverized laminae. The places where the seismites abut syndepositional faults are interpreted as evidence for their formation at the sediment-water interface during slip events on these faults. Thicker sediment accumulation above the seismites in the downthrown blocks indicates that a seismite formed at the water-sediment interface on both sides of the fault scarps. Modern analogs and the association with surface ruptures suggest that each seismite formed during a ML≥5.5 earthquake. The 230Th-234U ages of a columnar section, obtained by thermal ionization mass spectrometry, give a mean recurrence time of ∼1600 years of ML≥5.5 earthquakes in the Dead Sea Graben. The earthquakes cluster in ∼10,000-year periods separated by quiet periods of similar length. This distribution implies that a long-term behavior of the Dead Sea Transform should be represented by a mean recurrence of at least 20,000 year record. This observation has ramifications for seismic hazard assessment based on shorter records.

Original languageAmerican English
Pages (from-to)6179-6191
Number of pages13
JournalJournal of Geophysical Research: Solid Earth
Volume101
Issue number3
DOIs
StatePublished - 10 Mar 1996

Fingerprint

Dive into the research topics of 'Long-term earthquake clustering: A 50,000-year paleoseismic record in the Dead Sea Graben'. Together they form a unique fingerprint.

Cite this