Fagradalsfjall volcano update: Likelihood of volcanic eruption near Fagradalsfjall increases by the day
Fri, 12 Mar 2021, 16:0616:06 PM | BY: T
Recent earthquakes in the Reykjanes peninsula
The earthquake swarm in the Reykjanes peninsula, concentrated in the area around Mt. Fagradalsfjall SW of Keilir, continues with no signs of weakening. By early afternoon, the Iceland Met Office (IMO) had already recorded over 1700 earthquakes since midnight alone, including many of magnitude 3 or higher and a widely felt magnitude 5 event at 07:53 GMT this morning.
Latest satellite images and GPS data show that accumulation of magma is concentrated at the southern part of the dike beneath Mt. Fagradalsfjall. This is the most likely site for a possible eruption. InSAR image reflects changes between March 3 to March 9 2021. Image contains modified Copernicus Sentinel data  (image: IMO)
This seismic activity has been identified as result of continuing influx of magma into a newly forming dike (sheet-shaped magma reservoir) at shallow depth, of only about 1km beneath the surface in places. The longer it continues the higher the likelihood of it breaching the surface, or in other words causing a volcanic eruption.
Icelandic scientists concluded that "the dike intrusion is expanding with the most active magma flow centered at the southern part of it. A volcanic eruption remains a possibility as magma is still flowing into the corridor. With the ongoing activity the probability of an eruption increases day by day. It is considered very unlikely that lava from a possible eruption would reach populated areas.
The latest report by IMO further states:
- It is important to follow the activity in the southern region of Mt. Fagradalsfjall in order to evaluate whether the dike is expanding to the south.
- Latest satellite images and GPS data show that accumulation of magma is concentrated at the southern end of the dike beneath Mt. Fagradalsfjall. This is currently the most likely site for a possible eruption.
- If the dike keeps expanding and increasing stresses in the area, continuing earthquake activity that can be felt in populated areas is expected.
- Currently, the magma is shallow, lying 1-1,5 km beneath the crust. Therefore, it can be expected that an eruption could start without a strong precursory signal, as the magma can easily brake through the last hundreds of meters of the crust once the critical pressure is reached. From experience of lava flow eruptions (as we might expect), the eruption tremor is weak and has a low amplitude. For this reason, the IMO has installed webcams which can be used to monitor the area, in case of an eruption will start without clear precursory signals.
Thu, 11 Mar 2021, 07:30
In recent reports, the Icelandic Meteorological Office (IMO) stated that magmatic movements are the likely cause of the ongoing earthquake swarm in the Reykjanes peninsula. As magma migrates upwards, overlying rock layers are displaced, which causes tremors and ground deformation on the surface. ... Read all