Jökull - 01.12.2003, Blaðsíða 3

Reviewed research article
The 1783–1785 A.D. Laki-Grímsvötn eruptions I:
A critical look at the contemporary chronicles
Thorvaldur Thordarson
Department of Geology and Geophysics, University of Hawaii at Manoa, Honolulu Hawaii
and Science Institute, University of Iceland, Reykjavík, Iceland; moinui@soest.hawaii.edu
Abstract – The 1783–85 Laki-Grímsvötn eruptions are the best documented of the pre-twentieth century vol-
canic events in Iceland. A large body of contemporary sources contain information about the sequence of events
and eruption phenomena. A number of these are chronicles of these events and in Iceland they are known as
Eldrit (Book of Fire). The Eldrit compiled by the Reverend Jón Steingrímsson at Prestbakki in the Síða district
(about 35 km to the south of the Laki fissures) are by far the most detailed and informative. Here I evaluate
the accuracy and reliability of the Eldrit and other contemporary chronicles and show that, apart from minor
discrepancies, they give an accurate account of the course of events during the Laki eruption.
INTRODUCTION
The 1783–1784 Laki eruption was the main event
in the volcano-tectonic episode within the Grímsvötn
volcanic system that lasted from May 1783 to May
1785. The Laki event is the greatest natural disas-
ter in Iceland since its settlement in the 9th Century
and the only basaltic flood lava eruption witnessed
and reported on in detail by man. It is also the best
documented volcanic event in Iceland pre-dating the
twentieth century. These contemporary sources con-
tain valuable information about the eruption and its
effect on the environment and local communities (Ta-
ble 1, see also Thordarson et al., this issue and ref-
erences therein). Narratives, letters and official doc-
uments written before 1795 are considered contem-
porary, because they either document direct observa-
tions or are excerpts from descriptions obtained from
eyewitness accounts. A number of these are chroni-
cles of the eruption, or Eldrit (Book of Fire). Eldrit
is derived from the term eldur (fire), which was often
used by Icelanders to describe volcanic eruptions that
most commonly feature fire or lava fountain activity,
or as they saw it, columns of fires. The fourteen au-
thors listed in Table 1 documented in varying detail
the many aspects of the Laki eruption. The accuracy
and reliability of these accounts vary significantly, but
when evaluated critically, they are a rich source of in-
formation. Of the 20 accounts listed in Table 1 ten
are classified as Eldrit (Rafnsson, 1984). Those com-
piled by the Reverend Jón Steingrímsson are the most
detailed and informative.
Steingrímsson’s most famous description of the
Laki eruption, Fullkomið skrif um Síðueld (A com-
plete description of the Síða Fire), was completed in
1788 (Table 1). Recently an English translation of
the whole work was published for the first time (e.g.
Steingrímsson, 1998). This is truly one of the most
amazing eruption chronicles ever to be compiled, de-
spite its convoluted style, where direct observations
are mingled with and often obscured by religious con-
notations. Steingrímsson gives a vivid and truthful de-
scription of the eruptive events as well as the impact
the eruption had on the local communities. However,
Fullkomið skrif um Síðueld is not flawless and as will
be shown below inconsistencies do occur. Further-
more, the broader exposure of this most valued Eldrit
by Steingrímsson, along with the fact that existing in-
terpretations of the course of events during the Laki
JÖKULL No. 53, 2003 1