More than 130 earthquakes detected under a large volcano in Iceland as a possible precursor to an eruption

More than 130 earthquakes were registered throughout Iceland on Tuesday Bardarbunga volcanoa possible precursor to an eruption among several scenarios being considered, the Icelandic Meteorological Office said.

The aviation color code over the area was changed from green to yellow as a precaution, the weather office said, but the volcano’s remote location in the heart of the uninhabited highlands of southern Iceland meant no infrastructure was at risk.

The series of seismic events lasted for about three hours before it gradually subsided, the meteorological office it is stated in the press release.

“Shakes are still being felt in the area and it is too early to tell if the swarm will disappear,” it said.

The largest quake registered a magnitude of 5.1, while 17 other earthquakes of magnitude 3 or greater were detected, including at least two of magnitude 4 or greater.

The Bureau of Meteorology said the tremors were “consistent with increased inflation due to magma build-up” beneath Bardarbunga.

“The activity will be closely monitored, but it is difficult to say what the development will be at this time,” the weather office said.

The caldera or hollow of the central Bardarbunga volcano is about 25 square miles in size and is filled with ice.

It is one of six volcanic systems located under Europe’s largest glacier, Vatnajokull.

In the event of a subglacial eruption, there is a risk of ash eruption and subglacial flooding below Vatnajokull.

If the eruption occurred outside the glacier, it would be a lava eruption, the meteorological office explained.

“Seismic activity has increased in Bardarbunga in recent months,” it said, with Tuesday’s earthquake swarm the biggest since Bardarbunga’s last eruption in 2014-2015, which lasted six months.

“Bardarbunga is unique in that it is an unusually large volcanic system, partially covered by a glacier, and several scenarios are possible,” the agency said. “Extensive surveys, along with hazard assessments and contingency planning, were conducted during the 2014-2015 eruption, which will prove valuable should further volcanic activity occur.”

That eruption produced the largest flow of basaltic lava in Iceland in more than 230 years, but caused no injuries or damage.

Iceland has seen seven volcanic eruptions near the southwestern fishing village of Grindavik, which led to the evacuation of the town. After the seventh eruption, people were evacuated from about 50 homes in Grindavík, according to the country Civil Protection Agency.

Iceland has 33 active volcanic systems, more than any other European country.

It is located at the top of a rift between two tectonic plates, which makes this island nation vulnerable to earthquakes and volcanic eruptionswhich have shaken parts of the country and displaced residents in recent years.