Iceland Volcano Activity Shrouded in Mystery as Storm Hits

Officials in Iceland have warned that adverse weather will likely affect their ability to monitor the tectonic activity caused by increased magma pressure under the southwest of the nation's main island, while there remains a "high likelihood of volcanic eruption."

The Icelandic Meteorological Office said on Tuesday that a severe gale in the active region on Wednesday and Thursday would hamper both seismic instruments and GPS observations that have been tracking earthquakes and an uplift in the Earth's crust. It added that potential fog and hail could obfuscate an eruption were one to happen.

The last time a major eruption occurred in Iceland was in 2010, when the Eyjafjallajokull volcano erupted several times causing a massive ash cloud to spread over Europe and North America, leading to severe disruption to air travel.

Newsweek approached the Icelandic Met Office via email for further comment on Wednesday.

Scientists have been monitoring the elevated tectonic activity since November 10, when a magnitude 4.1 tremor occurred followed by a burst of others. The changes prompted local authorities to evacuate the fishing town of Grindavik, on Iceland's southwest peninsula, while cracks have appeared in the ground and across roads in the area.

As well as magma pushing the ground up by as much as 3 centimeters (nearly 1.2 inch) in the region, a vertical magma intrusion has formed close to Grindavik in a weak point in the Earth's crust, where molten rock is thought to be half a mile or less from the surface.

Experts suggested to Newsweek that a sudden shift in tectonic plates had prompted magma to push upwards, with the most likely location for an eruption to take place being above the vertical intrusion. However, they said there was disagreement among geologists about the nature of the eruption were it to occur.

Officials believe that an eruption could occur at any moment, necessitating accurate and timely tectonic activity data.

High winds of 56 miles an hour, with localized gusts of 67 miles an hour, as well as rainfall near Grindavik are expected in the next 48 hours. The Icelandic Met Office said that the effectiveness of its measuring instruments "depends on the high sensitivity of earthquake and real-time GPS measurements, which are highly dependent on weather conditions."

This chart, provided by Statista, shows countries with the most volcanoes that have been active since 1960.

"Ocean waves also create microseisms that overwhelm the low-frequency detection capabilities of seismometers" on the peninsula, it added. "Fog and hail showers could also affect the visual confirmation of an eruption, adding to the monitoring and assessment uncertainty."

While the uplift is occurring in an area on the peninsula with a diameter of approximately 10 kilometers (6 miles) to the north of Grindavik, the vertical intrusion has appeared along a straight line running southwest to northeast immediately next to Grindavik.

A rift between the North American and Eurasian tectonic plates sits underneath Iceland—which is thought to have been formed by volcanic activity 16-18 million years ago—with the two plates slowly moving apart from one another. A sudden shift in the North American plate would have created a wider gap and allowed magma to course upwards.

While an average of 1,500 to 1,800 earthquakes a day have been detected recently, the Icelandic Met Office said between midnight and 3:30 p.m. UT (10:30 a.m. ET) on Tuesday just 165 had been identified.

It warned that the poor weather conditions may have masked some of the seismic activity, "making it difficult to assess whether the seismic activity is decreasing overall."