Abstract

A δ 1 8 O 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 δ 1 8 O 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 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.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.