Jökull - 01.01.2019, Side 61

Sgattoni et al.
Figure 5. Cumulative number of earthquakes and cumulative seismic moment release during 1998–2015 in the
Goðabunga, Caldera and Gvendarfell seismic clusters, from IMO catalogue (events with magnitude ML > 1).
The moment-magnitude relation used is logM0 = 1.5M + 9.1, where M0 is the moment and M is the magnitude.
The 1999 and 2011 unrest episodes and the inflation period are marked with dashed lines. – Uppsafnaður fjöldi
skjálfta og uppsafnað skjálftavægi skjálfta 1998–2015 í þyrpingunum vestan Goðabungu, innan öskjunnar og
við Gvendarfell. Eingöngu eru teknir skjálfta með ML > 1. Gögn frá Veðurstofu Íslands. Samband milli
skjálftastærðar og skjálftavægis er: logM0 = 1.5M + 9.1, þar sem M0 er skjálftavægið og M er stærð skjálftans.
Atburðirnir 1999 og 2011 og þenslutímabilið 1999–2004 eru sýnd með strikalínum.
small, on the order of one hundred meters (Sgattoni et
al., 2016a). The Gvendarfell seismicity has faded out
since September 2017. The intensity of seismicity at
Katla volcano as a whole has been low over a similar
time scale (IMO data).
GEOLOGICAL FEATURES OF THE
GVENDARFELL AREA
A geological field study was carried out outside the
southern rim of the Katla caldera near the Gvendarfell
ridge, in the vicinity of the new 2011 seismic cluster
(Figure 6). This area is partly covered by the Mýrdals-
60 JÖKULL No. 69, 2019