Jökull - 01.12.2003, Blaðsíða 52

Þorbjarnardóttir and Guðmundsson
Figure 1. Earthquake epicenters (red dots) recorded during 2002 by the SIL seismic system plotted on a tectonic
map of Iceland. TFZ denotes the Tjörnes Fracture Zone, V the Vatnajökull ice sheet and M the Mýrdalsjök-
ull glacier. – Kort sem sýnir eldstöðvakerfi og brotabelti landsins ásamt jarðskjálftum (rauðir punktar) sem
staðsettir voru með SIL kerfinu árið 2002. Lítil virkni var í N og V-gosbeltunum, á Hengilssvæðinu og á
Reykjanesskaganum, talsverð virkni á Reykjaneshryggnum en mest í Tjörnesbrotabeltinu (TFZ).
quakes. Several earthquakes were also recorded about
20 km south of the mainshock.
MÝRDALSJÖKULL
Seismic activity beneath the western part of the Mýr-
dalsjökull glacier (Goðabunga) has changed over the
last semesters. Seasonal seismicity preferentially oc-
curring during the autumn months (Einarsson and
Brandsdóttir, 2000) has now been prolonged (Figure
3). Seismicity during the first months of 2002 was
of similar intensity as during the last months of 2001.
Though a decrease in the number of earthquakes was
observed during the spring and summer months, the
seismicity prevailed throughout the year. GPS mea-
surements show steady uplift and horizontal displace-
ment beneath the Katla caldera from 1999, which sug-
gests inflow of magma into the volcano (Sturkell et
al., 2003).
50 JÖKULL No. 53, 2003