Significant Earthquake Swarm Rocks Bárðarbunga: Over 130 Tremors Recorded Today
- Today’s most powerful quake registered at magnitude 5.1 at 8:05 AM, with 17 other earthquakes measuring 3 or higher.
- In recent months, seismic activity in the Bárðarbunga region has notably intensified.
- After a peak in activity until 9:00 AM, the frequency of earthquakes has started to wane.
- The aviation color code for Bárðarbunga has now been elevated to yellow.
- This massive volcano presents multiple possible scenarios for future developments.
Early this morning, just after 6:00 UTC, a vigorous earthquake swarm emerged in the northwestern area of the Bárðarbunga caldera. Since the onset, approximately 130 earthquakes have been registered, with the most notable tremor reaching a magnitude of 5.1 at 8:05 UTC.
Among these, 17 earthquakes registered a magnitude of 3 or higher, with at least two surpassing magnitude 4. As analysis continues, these figures may be subject to revision.
Seismic activity peaked until around 9:00 UTC, after which the tempo began to ease, although tremors continue to be recorded in the vicinity. At this stage, it is premature to conclude whether the swarm is subsiding.
A composite image from the Icelandic Meteorological Office’s monitoring system illustrates the earthquake activity. The map in the upper left highlights the seismic locations, identified by the black circle outlining the Bárðarbunga caldera. The upper-right graph presents the magnitude of earthquakes, with darker bars denoting reviewed events and lighter ones representing unreviewed data. The lower-left graph tracks the cumulative number of quakes, while the lower-right panel captures the hourly count.
Recent Activity: A Prelude to Potential Eruption?
This swarm marks the most significant geological activity in the Bárðarbunga region since the 2014-2015 eruption at Holuhraun. The current seismic events align with increased pressure due to magma accumulation, an ongoing phenomenon since the last eruption in 2015. In fact, earthquake activity has been on a gradual incline over the past few months, highlighted by the detection of four significant quakes in 2024. Geodetic data further indicates an uptick in inflation rates at the volcano.
Considering the Possible Outcomes
The Icelandic Meteorological Office is committed to close monitoring of the situation, though predicting future developments proves challenging. Bárðarbunga stands out as a massive volcanic system, partially cloaked by a glacier, which opens up a range of potential scenarios.
Insights gained from extensive research and risk assessments during the 2014-2015 eruption will be invaluable should further volcanic activity unfold.
Potential magma intrusions or dyke formations could spark eruptions outside the caldera, reminiscent of the Holuhraun eruption and the Gjálp eruption of 1996. Alternatively, the volcano could erupt within the caldera itself. Should lava break through beneath the glacier, it might trigger explosive ash emissions and dangerous glacial outburst floods (jökulhlaup). Conversely, an eruption occurring beyond the glacier could lead to a lava flow.
Given these developments, authorities have raised the aviation color code for Bárðarbunga to Yellow, indicating that seismic activity is above standard background levels.
For further insights into the Bárðarbunga volcanic system, consult the Catalog of Icelandic Volcanoes.