Jökull - 01.01.2005, Page 55

Holocene tephra stratigraphy and eruption frequency of Katla, S-Iceland
Figure 1. A map of the study area showing the location of the measured soil profiles. The prehistoric tephra
stratigraphy was documented in profiles at Atley (AT and HA) and Rjúpnafell (RF), whereas the historical
tephra stratigraphy was obtained from profiles at Hrífunes (H), Ytri-Dalbær (Y) and Tjaldgilsháls (T). – Kort
af rannsóknarsvæðinu og nágrenni. Jarðvegssnið með forsögulegum gjóskulögum voru mæld og sýnum safnað
á tveim stöðum í Atley (AT og HA) og í Rjúpnafelli (RF). Sýni af gjóskulögum frá sögulegum tíma eru úr
jarðvegssniðum á Tjaldgilshálsi (T), Ytri Dalbæ (Y) og Hrífunesi (H) (Guðrún Larsen 1981).
The only historical eruption in the Katla system out-
side of the central volcano was the 934–940 AD Eld-
gjá Fires, which is the largest known flood-lava erup-
tion on Earth during the historical period. The erup-
tion took place on a discontinuous 75 km-long SW-
NE trending volcanic fissure that produced 18.2 km 3
of lava and 1.4 km3 (DRE) of tephra (Larsen, 2000;
Thordarson et al., 2001). In the context of this outline
of historical activity on the Katla system, it is worth
noting that 87 years have passed since the last vis-
ible eruption (i.e. 1918). Increased precursor activ-
ity within the volcano in recent years suggests that an
eruption may be imminent.
Although much less is known about the prehis-
toric eruption history of the Katla system, the style
and nature of the activity during the Holocene ap-
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