Toba supereruption: Age and impact on East African ecosystems

Abstract

Lane et al. (1) recovered microscopic glass shards (cryptotephra) from a thin layer of sediment deposited in Lake Malawi and chemically characterized them as volcanic ash (Youngest Toba Tuff, YTT) from the Toba “supereruption” in Sumatra. The authors found no evidence of significant climate change at multidecadal to millennial timescales in the sedimentary record, and in their report conclude that the eruption distributed ash much more widely than previously documented but did not trigger a volcanic winter or human bottleneck in East Africa. Although the YTT event had limited impact on ecosystems around Lake Malawi, we think Lane et al. (1) are premature in extrapolating their environmental findings to all of East Africa, and we dispute their contention that “the most robust age for the YTT” is 75.0 ± 0.9 ka.