Jökull - 01.01.2001, Side 65

Real–time observations of the Laki sulfuric aerosol cloud
in Europe during 1783 as documented by
Professor S. P. van Swinden at Franeker, Holland
Þorvaldur Þórðarson

CSIRO Magmatic Ore Deposit Group, PO Box 5, Wembley, W.A. 6913, Australia

Stephen Self
Department of Geology and Geophysics, SOEST University of Hawaii at Manoa, Honolulu, Hawaii 96822, USA.
Abstract — The 1783-84 Laki (i.e. Skaftáreldar) eruption and the resulting Haze Famine caused the worst
environmental and social–economic disasters in Iceland’s history. However, the effects of the eruption were far
reached and the sulfuric aerosol cloud produced by Laki generated a persistent haze (dry fog) that hovered over
large parts of the Northern Hemisphere during the summer of 1783. This extraordinary state of the atmosphere
caused great public concern at the time and generated a wide–ranging interest among scholars and commoners
alike. Contemporary records contain a wealth of information on the occurrence of the Laki haze in Europe and
provide an invaluable insight into its immediate effects on the communities. Here we present one of the most
remarkable contemporary report on the subject; an essay written in 1784 by van Swinden, a Professor at the
University of Groningen in the Netherlands. This essay gives a vivid narrative of the appearance and effects
of the Laki haze and was published in 1785 by Meteorological Society of Mannheim. The first part of van
Swinden’s essay is allocated to his personal observations regarding the nature and appearance of the Laki
haze, followed by a comprehensive synopsis on its effects on the fauna. The latter half of the essay contains a
compendium of observations made on the appearance and impact of the Laki haze in Europe. Among the key
characteristics of the Laki haze was its dryness and for this very reason the haze was often referred to as the
“dry fog”, simply because it did not produce the moisture and dewdrops that accompany “normal fog”.
INTRODUCTION
Renewed interest in research on volcano–environment
interactions was inspired by Benjamin Franklin’s con-
jecture in 1784 that the dry fog that hung over Europe
in 1783 was produced by a volcanic eruption in Ice-
land (i.e. Lamb, 1970; Sigurdsson, 1982; Wood, 1984,
1992). The main emphasis of this research has been
on the climatic effects of volcanic eruptions by assess-
ing the potential radiative forcing induced by atmo-
spheric mass loading of sulfuric aerosols (e.g. Pollock
et al., 1976; Self et al., 1981; Rampino and Self,
1984; Angell and Korshover, 1985; Hoffmann, 1987;
Sigurdsson, 1990; Robock, 1991, Hansen et al.,
1993). However, research concerned with the im-
mediate effects of volcanic pollution on our natural
habitat and activities has gained momentum in recent
years (e.g. Grattan and Charman, 1994; Grattan and
Brayshay, 1995; Thordarson, 1995; Grattan, 1998; Ja-
coby et al., 1999).
Most Icelanders are familiar with the devasta-
tion that was brought about by the 1783–84 Laki
(i.e. Skaftáreldar) eruption on the late 18
 Cen-
tury communities in Iceland. The resulting Haze
Famine (i.e. Móðuharðindin) is the worst environmen-
tal and social-economic disaster in Iceland’s history
(Finnsson, 1796; Thorarinsson, 1979; and papers in
Now at Department of Geology and Geophysics, SOEST,
University of Hawaii at Manoa, Honolulu, Hawaii 96822, USA.
JÖKULL No. 50 65