| SPELEOTHEMS |
Lachniet et al. 2004 Venado Cave, Costa Rica Speleothem Stable Isotope Data
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Lachniet, M.S.;Asmerom, Y. 2004 Tropical response to the 8200 yr B.P. cold event? Speleothem isotopes indicate a weakened
early Holocene monsoon in Costa Rica. Geology Vol. 32, No. 11, pp. 957-960.
| Data Coverage |
North: 10.6 * South: 10.6 |
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West: -84.8 * East: -84.8 |
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Altitude: 380 m |
Start Year: -6856 AD
End Year: -2986 AD
Data: Please Cite Data Contributors!
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Summary: A delta 18O monsoon rainfall proxy record from a U-Th-dated Costa Rican stalagmite
(8840-4920 yr B.P.) documents an early Holocene dry period correlative with the
high-latitude 8200 yr B.P. cold event. High delta 18O values between ca. 8300 and
8000 yr B.P. demonstrate reduced rainfall and a weaker monsoon in Central America.
A relatively wetter and more stable monsoon was established at ca. 7600 yr B.P.
The early Holocene dry event suggests a tropical-extratropical teleconnection
to the 8200 yr B.P. cold event and a possible association of isthmian rainfall
anomalies with high-latitude climate changes. The likely source of such a
tropical anomaly is a decrease in Atlantic thermohaline circulation and
atmospheric perturbations associated with drainage of proglacial lakes and
freshwater discharge into the North Atlantic. A weaker monsoon at 8200 yr B.P.
may be linked to wetland contraction and a decrease in methane observed in
Greenland ice cores.
More Info on Speleothems |
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Complete XML Record: noaa-cave-5429
(Last Revised: 2009-02-11 )
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