HR: 08:15h
AN: T41E-02 INVITED    [Abstracts]
TI: Paucity of Historical Earthquakes South of the Dead Sea: Is it Real?
AU: * Niemi, T M
EM: niemit@umkc.edu
AF: University of Missouri-Kansas City, Dept. of Geosciences, 5100 Rockhill Road, Kansas City, MO 64110, United States
AB: The long cultural record of Dead Sea Transform (DST) earthquakes provides a unique opportunity for studying the patterns of seismicity over multiple seismic cycles, especially if rupture and/or epicentral areas of historical earthquakes can be identified. It has long been noted that the modern rate of seismic activity in the Wadi ‘Arabah (Arava) south of the Dead Sea is lower than other segments of the DST and few historical earthquakes have been located south of the Dead Sea. Does the tendency to assign most epicentral locations north of the Dead Sea reflect a bias toward higher ancient settlement patterns? Seismites studied in Israel suggest a millennial-scale clustering of seismicity with a paucity of activity during the 6th-11 centuries. However, comparison of the timing of fault rupture constrained by paleoseismic trenching, archaeoseismic excavations, and radiocarbon and archaeological artifact dating from sites on the northern Wadi ‘Arabah fault (Qasr Tilah area) and in Aqaba in Jordan suggests a temporal correlation of earthquake activity along the full length of the DST south of the Dead Sea during this quiescent period. Our data indicate a major period of seismic activity during the late 6th to 8th centuries. Furthermore, faulting and architectural collapse during the 2nd and 4th centuries indicate other periods of increased earthquake activity. Evidence for 2-3 additional ruptures in the 9th-16th centuries that are attested to by historical accounts, while evident in the geologic faulting record are poorly constrained by independent age control. At least one of these events is likely the 1068 earthquake. Correlation of earthquakes from the north and south ‘Arabah indicate either very long fault rupture (about 160 km) or multiple ruptures on adjacent fault segments that are closely spaced in time. In Aqaba, multiple ruptures during these earthquake intervals may indicate both foreshock and main events similar to the seismic sequence preceding the 1995 Nuweiba earthquake. Greater coseismic slip in the pre-11th century earthquakes compared to the last millennium suggests large potential strain accumulation and a long elapsed time since the last major earthquakes south of the Dead Sea with important implications for the seismic hazard of the region. Furthermore, these data suggest that historical earthquake catalogues are incomplete with regard to some of the earthquakes that have affected southern Jordan.
DE: 7221 Paleoseismology (8036)
DE: 8036 Paleoseismology (7221)
SC: Tectonophysics [T]
MN: 2007 Fall Meeting