TY  - JOUR
A1  - Jöhnck, Janika
A1  - Kuhnt, Wolfgang
A1  - Holbourn, Ann
A1  - Andersen, Nils
T1  - Variability of the Indian Monsoon in the Andaman Sea Across the Miocene-Pliocene Transition
Y1  - 2020
VL  - 35
IS  - 9
JF  - Paleoceanography and Paleoclimatology
DO  - 10.1029/2020PA003923
DO  - 10.23689/fidgeo-4929
N2  - We reconstructed the variability of the Earth's strongest hydrological system, the Indian monsoon, over the interval 6.24 to 4.91 Ma at International Ocean Discovery Program (IODP) Expedition 353 Site U1448 in the Andaman Sea. We integrated high-resolution benthic and planktic foraminiferal carbon and oxygen isotopes with Mg/Ca measurements of the mixed layer foraminifer Trilobatus sacculifer to reconstruct the isotopic composition of seawater (δ18Osw) and the gradient between planktic and benthic foraminiferal δ13C. A prominent increase in mixed layer temperatures of ~4°C occurred between 5.55 and 5.28 Ma, accompanied by a change from precession- to obliquity-driven variability in planktic δ18O and δ18Osw. We suggest that an intensified cross-equatorial transport of heat and moisture, paced by obliquity, led to increased summer monsoon precipitation during warm stages after 5.55 Ma. Transient cold stages were characterized by reduced mixed layer temperatures and summer monsoon failure, thus resembling late Pleistocene stadials. In contrast, an overall cooler background climate state with a strengthened biological pump prevailed prior to 5.55 Ma. These findings highlight the importance of internal feedback processes for the long-term evolution of the Indian monsoon.
UR  - http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/9275
ER  -