Seasonally resolved stratigraphy at Jwalapuram India shows regional surface warming after the Toba volcanic super-eruption

Abstract

Understanding the nature and tempo of global environmental responses to the ∼74,000 BP (∼74 ka) Toba volcanic super-eruption is based primarily on historical analogies and climate models that lack ground-truthing in regions distal to eruptions. Here, we report the first proxy-based terrestrial record of the immediate environmental impact of the Younger Toba Tuff (YTT) eruption on the homininoccupied ecosystem in peninsular India, spanning six annual monsoonal cycles directly following the YTT event. We present a multiproxy paleoclimate dataset from Jwalapuram in southern India, featuring a geochemical characterization of multiple YTT tephra and hardpan layers, complemented by detailed stratigraphic observations, sedimentological insights, and stable carbon isotope data. Taken together, these multiple lines of evidence show a progressive trend of tephra weathering and strong evapotranspiration in the immediate aftermath of the YTT, suggesting multiannual regional warming. Our results underline the complex responses of regional environments to the Toba super-eruption, which extend beyond a simple widespread “volcanic winter.”