Multi-proxy validation of glacial-interglacial rainfall variations in southwest Sulawesi

Date

2023

Authors

Kimbrough, Alena
Gagan, Michael
Dunbar, Gavin
Hantoro, Wahyoe
Shen, Chuan-Chou
Hu, Hsun-Ming
Cheng, Hai
Edwards, Lawrence
Rifai, Hamdi
Suwargadi, Bambang W

Journal Title

Journal ISSN

Volume Title

Publisher

Nature Publishing Group

Abstract

Speleothem δ18O is widely used as a proxy for rainfall amount in the tropics on glacial-interglacial to interannual scales. However, uncertainties in the interpretation of this renowned proxy pose a vexing problem in tropical paleoclimatology. Here, we present paired multi-proxy geochemical measurements for stalagmites from southwest Sulawesi, Indonesia, and confirm changes in rainfall amount across ice age terminations. Collectively, the stalagmites span two glacial-interglacial transitions from ~380,000 to 330,000 and 230,000 to 170,000 years ago. Mg/Ca in the slow-growing stalagmites is affected by water moving through the karst and prior calcite precipitation, making it a good proxy for changes in local rainfall. When paired, Mg/Ca and δ18O corroborate prominent shifts from drier glacials to wetter interglacials in the core of the Australasian monsoon domain. These shifts in rainfall occur 4,000-7,000 years later than glacial-interglacial increases in global temperature and the associated response of Sulawesi vegetation, determined by speleothem δ13C.

Description

Keywords

Citation

Source

Communications Earth & Environment

Type

Journal article

Book Title

Entity type

Access Statement

Open Access

License Rights

Creative Commons Attribution licence

Restricted until

Downloads