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| Titel |
Megadroughts at the dawn of Islam recorded in a 2600-year long stalagmite from Northern Oman |
| VerfasserIn |
D. Fleitmann, M. Mudelsee, R. S. Bradley, P. Pickering, J. Kramers, S. J. Burns, A. Mangini, A. Matter |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250026303
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| Zusammenfassung |
| Climate on the Arabian Peninsula is strongly affected by two major climate systems; the
North Atlantic/Siberian pressure system in winter and the Indian monsoon in summer. Their
influence is clearly discernable in the present-day precipitation pattern in Oman. Southern
Oman (so-called Dhofar region) receives most of its total annual precipitation during the
Indian summer monsoon (June – August), whereas northern Oman receives most
precipitation during the northeast monsoon season (December – March) by southeast ward
moving Mediterranean frontal system. To date, the late Holocene climatic history of Oman
and the entire Arabian Peninsula is poorly understood due to the lack of well dated and highly
resolved paleoclimate records. In order to fill this gap of knowledge an actively growing
stalagmite (specimen H12) was collected from Hoti Cave located in northern Oman.
Total annual rainfall in this area varies between 50 and 255 mm yr-1, with more
than 65% of total annual rainfall occurring between December and March. The
chronology of stalagmite H12 is based on 22 Th-U ages, which indicate that H12 grew
continuously during the last 2650 years. The H12 oxygen isotope record (δ18O) is
based on 1345 measurements corresponding to a temporal resolution of around 2
years. The comparison of the H12 δ18O record with meteorological data reveals
that δ18O values reflect the amount of precipitation. The H12 δ18O time series
shows distinct centennial- to decadal-scale changes in the amount of precipitation.
The most striking feature of the H12 isotope profile is a series of severe droughts
between A.D. 500 and A.D. 1000, the most severe perennial drought is centered at
around A.D. 530. During this time South Arabia experienced a series of profound
societal changes, such as the collapse of the Himyarite Kingdom which was the
dominant state in Arabia. Our stalagmite δ18O time series from Northern Oman seems
to support the hypothesis that the collapse of the 1500-year-old South Arabian
civilizations and transition from the pre-Islamic to the Islamic era in the 6th and
early 7th century A.D. may have been triggered by reoccurring severe droughts. |
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