Drought in the northern Bahamas from 3300 to 2500 years ago. (15th April 2018)

• Record Type: Journal Article
• Authors: van Hengstum, Peter J.; Maale, Gerhard; Donnelly, Jeffrey P.; Albury, Nancy A.; Onac, Bogdan P.; Sullivan, Richard M.; Winkler, Tyler S.; Tamalavage, Anne E.; MacDonald, Dana
• Is Part Of: Quaternary science reviews. Volume 186(2018)
• Page Start: 169
• Page End: 185
• Publication Date: 2018-04-15
• Subjects: Geology, Stratigraphic -- Quaternary -- Periodicals; Stratigraphie -- Quaternaire -- Périodiques; 551.79
• DOI: 10.1016/j.quascirev.2018.02.014
• Languages: English
• ISSNs: 0277-3791

Abstract

Abstract: Intensification and western displacement of the North Atlantic Subtropical High (NASH) is projected for this century, which can decrease Caribbean and southeastern American rainfall on seasonal and annual timescales. However, additional hydroclimate records are needed from the northern Caribbean to understand the long-term behavior of the NASH, and better forecast its future behavior. Here we present a multi-proxy sinkhole lake reconstruction from a carbonate island that is proximal to the NASH (Abaco Island, The Bahamas). The reconstruction indicates the northern Bahamas experienced a drought from ∼3300 to ∼2500 Cal yrs BP, which coincides with evidence from other hydroclimate and oceanographic records (e.g., Africa, Caribbean, and South America) for a synchronous southern displacement of the Intertropical Convergence Zone and North Atlantic Hadley Cell. The specific cause of the hydroclimate change in the northeastern Caribbean region from ∼3300 to 2500 Cal yrs BP was probably coeval southern or western displacement of the NASH, which would have increased northeastern Caribbean exposure to subsiding air from higher altitudes. Highlights: The North Atlantic Subtropical High (NASH) is a regulator of Northern Caribbean rainfall. A 6500-year sinkhole-lake level reconstruction is documented from the northern Bahamas. Increased lake salinity and benthic anoxia suggests drought from 3300 to 2500 years ago. The Intertropical Convergence Zone shifted south from 3300 to 2500 years ago. A coeval southern NASH displacement likely drove aridity in the study area.