Climate-volcanism feedback and the toba eruption of ∼74,000 years ago

Michael R. Rampino, Stephen Self

Research output: Contribution to journalArticle

Abstract

A general feedback between volcanism and climate at times of transition in the Quaternary climate record is suggested, exemplified by events accompanying the Toba eruption (∼74,000 yr ago), the largest known late Quaternary explosive volcanic eruption. The Toba paroxysm occurred during the δ18O stage 5a-4 transition, a period of rapid ice growth and falling global sea level, which may have been a factor in creating stresses that triggered the volcanic event. Toba is estimated to have produced between 1015 and 1016 g of fine ash and sulfur gases lofted in co-ignimbrite ash clouds to heights of at least 32 ± 5 km, which may have led to dense stratospheric dust and sulfuric acid aerosol clouds. These conditions could have created a brief, dramatic cooling or “volcanic winter,” followed by estimated annual Northern Hemisphere surface-temperature decreases of ∼3° to 5°C caused by the longer-lived aerosols. Summer temperature decreases of ≥10°C at high northern latitudes, adjacent to regions already covered by snow and ice, might have increased snow cover and sea-ice extent, accelerating the global cooling already in progress. Evidence for such climate-volcanic feedback, following Milankovitch periodicities, is found at several climatic transitions.

Original languageEnglish (US)
Pages (from-to)269-280
Number of pages12
JournalQuaternary Research
Volume40
Issue number3
DOIs
StatePublished - Nov 1993

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ASJC Scopus subject areas

  • Arts and Humanities (miscellaneous)
  • Earth-Surface Processes
  • Earth and Planetary Sciences(all)

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