Jökull - 01.01.2017, Blaðsíða 7

Zeinab Jeddi et al.
Figure 1. Map of the Katla volcanic system showing the caldera outline with a hatched line, the central volcano
with a solid outline, and the fissure swarm with a dashed line (Einarsson and Sæmundsson, 1987). Glaciers are
white. Pathways for glacial discharge are illustrated with black arrows on the rim of Katla’s caldera. Geother-
mal cauldrons on the surface of Mýrdalsjökull glacier are indicated by open circles (Guðmundsson et al., 2007).
The inset in the upper left corner shows a tectonic map of Iceland, which includes the study area outlined with
a black rectangle. Topography information from the National Land Survey of Iceland. – Kort af Kötlueld-
stöðinni og umhverfi hennar sýnir Kötluöskjuna með hakaðri línu, megineldstöðina með svartri línuumgjörð og
sprungusveiminn með brotalínu (eftir Einarsson og Sæmundsson, 1987). Jöklar eru hvítir. Mögulegar flóðleiðir
úr öskjunni eru sýndar með svörtum örvum. Sigkatlar á yfirborði Mýrdalsjökuls eru sýndir með opnum svörtum
hringjum (eftir Guðmundsson og fl., 2007). Innfelld mynd í efra vinstra horni sýnir eldfjallakerfi á Íslandi öllu
og svæðið á stærri myndinni innan svarts ferhyrnings. Landhæðarupplýsingar frá Landmælingum Íslands.
(IMO), started in 1988 as a collaborative project on
earthquake prediction between the Nordic countries
(Stefansson et al., 1993). The first SIL station close to
Mýrdalsjökull, MID, was installed in 1990. The seis-
mic network has since been densified around Katla
to five stations in 2010 and ten stations shortly af-
ter the 2010 eruption of neighboring Eyjafjallajökull,
centered 25 km west of Katla. In addition, nine tem-
porary stations were deployed in 2011 and operated
until 2013 by Uppsala University (UU) and Reykjavik
University (RU) to monitor the volcano closely.
The seismic activity at Katla has been concen-
trated in two main regions: within the caldera and on
the west flank at Goðabunga (Einarsson, 1991; Soos-
alu et al., 2006; Jónsdóttir et al., 2007). Moreover, a
new seismic source region became active on the south
flank in 2011 (Sgattoni et al., 2016a). Yet another
seismic cluster was recently identified on the east
flank of Katla, largely thanks to the temporary net-
work (Jeddi et al., 2016). A variety of seismic events,
both high-frequency (>5 Hz) and low-frequency (3–
5 Hz), have been reported at Katla. According to the
2 JÖKULL No. 67, 2017