Climatic and societal impacts of a \u201cforgotten\u201d cluster of volcanic eruptions in 1108-1110 CE

Francis Ludlow,Christophe Corona,Sébastien Guillet,Markus Stoffel,Clive Oppenheimer

doi:10.1038/s41598-020-63339-3

Abstract

Recently revised ice core chronologies for Greenland have newly identified one of the largest sulfate deposition signals of the last millennium as occurring between 1108 and 1113 CE. Long considered the product of the 1104 CE Hekla (Iceland) eruption, this event can now be associated with substantial deposition seen in Antarctica under a similarly revised chronology. This newly recognized bipolar deposition episode has consequently been deemed to reveal a previously unknown major tropical eruption in 1108 CE. Here we show that a unique medieval observation of a “dark” total lunar eclipse attests to a dust veil over Europe in May 1110 CE, corroborating the revised ice-core chronologies. Furthermore, careful evaluation of ice core records points to the occurrence of several closely spaced volcanic eruptions between 1108 and 1110 CE. The sources of these eruptions remain unknown, but we propose that Mt. Asama, whose largest Holocene eruption occurred in August 1108 CE and is credibly documented by a contemporary Japanese observer, is a plausible contributor to the elevated sulfate in Greenland. Dendroclimatology and historical documentation both attest, moreover, to severe climatic anomalies following the proposed eruptions, likely providing the environmental preconditions for subsistence crises experienced in Western Europe between 1109 and 1111 CE.

Highlights

Revised ice core chronologies for Greenland have newly identified one of the largest sulfate deposition signals of the last millennium as occurring between 1108 and 1113 CE
Using high-resolution ice core glacio-chemical measurements, automated ice-core layer counting, well-dated and independent time markers, tephra markers and historical reports of atmospheric phenomena associated with volcanic aerosol presence, Sigl et al.[6] demonstrated that ice core records relying upon the Greenland Ice Core Chronology 2005 (GICC05) timescale required a correction of approximately seven years in the first millennium CE, and up to four years in the period we study in this paper
To identify as well as spatially and temporally characterize potential climatic impacts arising from these eruptions, which we describe as the 1108-1110 CE volcanic cluster, we employ a tree-ring network of 25 NH chronologies (Table S3, Fig. S15)

Summary

Introduction

Revised ice core chronologies for Greenland have newly identified one of the largest sulfate deposition signals of the last millennium as occurring between 1108 and 1113 CE. Using high-resolution ice core glacio-chemical measurements, automated ice-core layer counting, well-dated and independent time markers (including the cosmic-ray events of 774 and 993 CE), tephra markers and historical reports of atmospheric phenomena (e.g., dust veils) associated with volcanic aerosol presence, Sigl et al.[6] demonstrated that ice core records relying upon the Greenland Ice Core Chronology 2005 (GICC05) timescale required a correction of approximately seven years in the first millennium CE, and up to four years in the period we study in this paper. A prominent discovery arising from this revised ice-core dating is a major and hitherto unrecognized bipolar volcanic signal with sulfate deposition starting in late 1108 or early 1109 CE and persisting until early 1113

Methods

Conclusion