Tilkynning um breytingu á litakóða eldfjalls

Reykjanes

Tími: 18. mar. 2020, 15:57

Litakóði:  Gulur 

Númer eldfjalls: 371020

Virkniyfirlit:
Scientists from the Icelandic Meteorological Office, University of Iceland and ISOR met yesterday (18.03) to review the latest monitoring data for the Reykjanes-Svartsengi volcanic system. From the most recent GPS data and InSAR processing, it is now evident that the deformation around Þorbjörn is started again. The uplift that occurred in the area in January-February this year halted temporarily at the end of February and began again during the second week of March. The rate of deformation seems to be lower than before. The total uplift observed since the beginning of March is about 20 mm. Both GPS data and the modelling results suggest that the deformation is occurring in the same location as before and caused by a similar source. The most likely explanation is magma inflow at a depth of about 4.5 km. The ongoing inflation might have triggered the large earthquake (M4.6) that occurred in the area on the 12th of March at about 3.5 km NE of Mt. Þorbjörn. A sequence of aftershocks lasted for a couple of days featuring eight earthquakes > M3 and about eighty earthquakes with magnitudes between 2 and 3. Since then a total of 850 earthquakes have been detected in the area. Gas measurements are done regularly each week in the area. No significant changes have been detected so far. Given the level of the uncertainty for the area and given the confirmed inflation ongoing around Þorbjörn, IMO decided to change again the aviation color code from GREEN to YELLOW.

Hæð gosmökkvar:
No eruption ongoing.

Aðrar upplýsingar um gosmökk:
No eruption ongoing.

Nánar um vá:
The inflation occurred on plate boundaries and within the volcanic system of Svartsengi which is either considered a separate system or part of the Reykjanes volcanic system. The last known eruption was during Reykjanes fires, which occurred between 1210-1240 AD. Within that period a several eruptions occurred within that system, thereof there were three eruptions in Svartsengi system. The eruptions were effusive (non-explosive) fissure eruptions erupting on 1-10 km long fissures. No explosive eruptions are known from this system. The largest eruption in the swarm, from 13th century, formed Arnarseturshraun lava (estimated 0,3 km3 and 20 km2). The duration of these eruptions are usually from a few days up to several weeks. Seismic activity is very common in this area and is linked to the plate boundaries, geothermal activity and possible magma intrusions. The largest earthquakes measured in this area are about M5.5. For more information please check the Catalogue of Icelandic volcanoes at http://icelandicvolcanoes.is/?volcano=REY.




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