Jökull - 01.12.2003, Blaðsíða 49

The 1783–1785 Laki-Grímsvötn eruptions
Table C: Lava flows, continued.
Date Index Source Quotation
9 August C40 2, p. 67 ...that day a lava surge emerged from Hverfisfljót River gorge and advanced like running water out onto the sandur plain,
one mile [i.e., Danish mile = 7532 m] beyond the so called Orustuhóll Hillock and from there due south until it stopped.
[The correct distance which the lava advanced beyond Orustuhóll is 4 km].
10–17 Aug. C41 4, p. 27 ...intensive flow of lava out of the gorge, so it was feared that it might advance over the Fljótshverfi district.
17-23 Aug. C42 4, p. 28 ...the flow of lava had dwindled considerably [from Hverfisfljót River gorge].
1 Sept. C43 4, p. 28 ...the second lava surge emerged out of Austurgjá. [As is evident from the quotation above this was the second lava surge
to emerge from the Hverfisfljót River gorge].
1-7 Sept. C44 4, p. 29 ...the lava flow was so vigorous north of the mountains [bordering the Síða district] that it dried up and consumed all
rivers which used to flow out on the sandur plain.
10–11 Sept. C45 4, p. 29 ...yet another lava surge emerged out of the same gjá and advanced between the previously formed lava streams. [This is
the third lava surge to emerge from the Hverfisfljót River gorge].
14–26 Sept. C46 4, p. 29 ...a great break in flow of lava out from both gorges ...because both Skaftá and Hverfisfljót rivers along with all local
tributaries have reappeared and not caused any considerable damage.
26 Sept. C47 4, p. 29 ...was followed by increasing activity and lava production north of the mountains [bordering the Síða district] and again
dried up all the rivers which had reappeared earlier, so people could walk unhindered across the lava for example next
to the farm Skaftárdalur as mentioned above. [This lava surge dried up the Skaftá and Hverfisfljót rivers again. This
increase in the activity is most likely related to the formation of one of the fissures at Fljótsoddi, because it is between to
the glacial outlets of both rivers, which are separated by less than 2 km. This is the fourth lava surge to emerge from the
Hverfisfljót River gorge].
25 October C48 4, p. 30 ...a high column of fire ascended into the air from there [i.e., Grímsvötn], which was followed by a aweful lava surge
[from Landnorðursgjá] along with rumble and claps for the next five days. This was the last lava surge that emerged
from Hverfisfljót gorge and it was also the most fearful and intensive surge, which the Lord God directed between the
earlier ones.
November C49 4, p. 31 All November small lava pulses flowed onto the eastern lava branch, so rumbles were heard.
in 1784 C50 4, p. 32 Neither I or other trustworthy inhabitants observed any lava flowing out of the two gjá’s, which had produced the bulk
part of the lava flow, after 7 February or when 15 weeks had passed of the winter. This eruption lasted therefore for 8
months.
Table D: Sense of directions in the Fire Districts
Date Index Source Quotation
8 June D1 1, p. 272 After a period of intensive earthquakes eldgjá started to erupt, on 8 June, in so called Síða highlands due southwest of
Úlfarsdalur glacier. [This indicates that southwest was sensed from N215◦ to 225◦E].
8 June D2 5, p. 274 On Whitsunday I first saw a fire column and smoke northeast from my home [Ljótarstaðir in Skaftártunga], but north of
Síða, which were thought to be located within the glacier where Grímsvötn are situated. [The direction from Ljótarstaðir
to the craters at Hnúta is N24◦E, i.e., northeast = N24◦E].
8 June D3 6, p. 296 Three columns of fire were seen from the central part of Síða or north of the Mörtunga valley as it was seen from the
farm Prestbakki ...[A line from Prestbakki to Mörtunga is the direction towards the southwestern most craters of the Laki
cone-row. Consequently the direction for northwest is actually N320◦E as sensed in the Síða district at the time of the
eruption].
9 June D4 4, p. 9 But the Skaftá River flowed to east along the Síða escarpment. [This is one of many descriptions where Steingrímsson
says that east was parallel to the scarp. Therefore east = N65◦to 75◦E].
12 June D5 4, p. 9 To begin with the lava advanced along the main channel of river [Skaftá], flowed out over the older lavas [Eldgjá lava,
934 AD], which were on either side of the river extending from the gorge east towards Stapafoss. [The Skaftá River ran
eastward along the scarp and Stapafoss was a waterfall in the river next to the hillock Systrastapi. The line of view from
the lava fields towards Systrastapi is parallel to the scarp. East = N65◦ to 75◦E].
16 June D6 4, p. 11 It, [i.e., farm Brandaland] was located west-southwest of the Skálarstapi. Hillock... [This gives west-southwest = N245◦
to 255◦E].
17 June D7 4, p. 13 ...the column of fire rose up so high, from the before mentioned Útnorður Úlfarsdalsgjá [the northwest fissure located
in Úlfarsdalur Valley] from where a continuous boiling sound could be heard, that it actually advanced forward between
Lambatungur, located at the west end of Kaldbakur, and Geirlandshraun, which is a elongated hill north of the Síða
district, trending east-west and stretches so far west that it reaches beyond the farm Skál. The fire column was seen from
Prestbakki farm above the Geirlandsheiði moor. [Here the orientation of Geirlandshraun is said to be east-west, but is
actually N70◦E].
19 June D8 4, p. 14 At this time the main lava stream advanced with flying cinders southeast towards Meðalland, mostly it flowed down the
channel of River Melakvísl which before connected Skaftá River and Botnafljót River. [This gives southeast = N150◦E].
24 June D9 4, p. 15 On before mentioned 24 June, the new lava had built up a high pile, I was standing up on a cliff just north of the farm
Efri-Steinsmýri, looking west over the lava flow and could only see the top of Mt. Hafursey. [This gives west = N265◦E].
JÖKULL No. 53, 2003 47