https://dx.doi.org/10.1029/96GL02201">
 

Abstract

Continuous measurements of SO42− and electrical conductivity (ECM) along the GISP2 ice core record the Toba mega‐eruption at a depth 2590.95 to 2091.25 m (71,000±5000 years ago). Major chemical species were analyzed at a resolution of 1 cm per sample for this section. An ∼6‐year long period with extremely high volcanic SO42− coincident with a 94% depletion of nitrate and 63% depletion of chloride is observed at the depth of the Toba horizon. Such a reduction of chloride in a volcanic layer preserved in an ice core has not been observed in any previous studies. The nearly complete depletion of nitrate (to 5 ppb) encountered at the Toba level is the lowest value in the entire ∼250,000 years of the GISP2 ice core record. We propose possible mechanisms to explain the depletion of nitrate and chloride resulting from this mega‐eruption.

Publication Date

9-1-1996

Journal Title

Geophysical Research Letters

Publisher

American Geophysical Union (AGU)

Digital Object Identifier (DOI)

https://dx.doi.org/10.1029/96GL02201

Document Type

Article

Rights

©1996. American Geophysical Union. All Rights Reserved. This is an article published by AGU in Geophysical Research Letters in 1996, available online: https://dx.doi.org/10.1029/96GL02201

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