Depletion of Atmospheric Nitrate and Chloride as a Consequence of the Toba Volcanic Eruption

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 ext...

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Bibliographic Details
Main Authors: Yang, Q., Mayewski, Paul Andrew, Zielinski, G. A., Twickler, M., Taylor, K. C.
Format: Text
Language:unknown
Published: DigitalCommons@UMaine 1996
Subjects:
Glaciogeology
Geochemistry
Glaciology
Cryology
Climate Change
Climate
Earth Sciences
Hydrology
Volcanology
ice core
Online Access:https://digitalcommons.library.umaine.edu/ers_facpub/194
https://digitalcommons.library.umaine.edu/cgi/viewcontent.cgi?article=1194&context=ers_facpub
Description
Summary: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.

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