Document Type

Article

Publication Title

Journal of Geophysical Research

Publisher

American Geophysical Union

Rights and Access Note

This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. In addition, no permission is required from the rights-holder(s) for educational uses. For other uses, you need to obtain permission from the rights-holder(s).

Publication Date

12-27-1997

First Page

30,031

Last Page

30,045

Issue Number

D25

Volume Number

102

Abstract/ Summary

Variability in the SO 4 2 - and Cl− time series for the 1980s from 12 shallow snow pits across the Greenland ice sheet is used to evaluate the record of the 1982 El Chichón eruption and the potential for recording a moderate northern equatorial eruption in a single Greenland ice core. Composition of volcanic glass found in spring 1983 snow in one of the pits in the Summit region matches that from El Chichón glass, thereby verifying the deposition of material from the eruption. High Na+ and Cl− concentrations in this same layer probably represent deposition of the reaction products of halite and H2SO4 as observed in the stratosphere following the eruption. These findings and the presence of a Cl−signal in five of the other pits indicate that the Cl− aerosol component of some eruptions has the potential to remain aloft for at least 1 year after the eruption. Some of these aerosols may be adsorbed onto tephra particles. Distinct SO 4 2- peaks that can be confidently linked to El Chichón were found in only 50% of the records developed through subseasonal sampling. However, in several other pits an elevated baseline, thought to represent more lengthy periods of El Chichón aerosol deposition as opposed to deposition from a single snowfall event, were observed. Smoothing of the original data by the calculation of annual SO 4 2 - flux resulted in the presence of high flux values between 1982 and 1984 (years thought to be affected by El Chichón aerosol deposition) in 9 of the 12 pits. These results suggest that a single ice core from anywhere in Greenland may record a signal from a northern equatorial eruption of magnitude similar to that of El Chichón about 75% of the time; this is despite the overall high levels of SO2− 4 deposition from anthropogenic sources that now make identification and quantification of the volcanic SO2− portion of the record more difficult than obtaining the same data for preindustrial volcanism. Nevertheless, composite records from all the pits sampled yielded stratospheric loading (∼20 Mt) and optical depth (τ = 0.13) estimates similar to stratospheric and satellite-based measurements following the eruption. Equally high SO 4 2 - concentration and flux values in snow from 1980 to 1982 reflect deposition from the series of middle to high northern latitude volcanic eruptions 1979–1981.

Citation/Publisher Attribution

Zielinski, G. A., J. E. Dibb, Q. Yang, P. A. Mayewski, S. Whitlow, M. S. Twickler, and M. S. Germani (1997), Assessment of the record of the 1982 El Chichón eruption as preserved in Greenland snow, Journal of Geophysical Research, 102(D25), 30,031–30,045, doi:10.1029/97JD01574.

Publisher Statement

© Copyright 1997 by the American Geophysical Union

DOI

10.1029/97JD01574

Version

publisher's version of the published document

Download

Share

 

Rights Statement

In Copyright - Educational Use Permitted.