Bardarbunga, a stratovolcano located under the largest glacier in Iceland, is the center of attention there, as thousands of small earthquakes are starting to shake the island nation. Over 3,000 earthquakes have been recorded in the country since 16 Aug.
Aviation warnings in Iceland have been raised to orange, the fourth of five levels, and the second-most serious. This indicates an eruption is possible but not imminent.
The Eyjafjallajokull volcano is currently showing signs that magma is moving horizontally, although earthquakes have become less common after the first wave of tremors.
Earthquakes started on 16 Aug., but most have not yet been serious on their own. Nearly all the tremors have registered three or lower on the Richter Scale, barely noticeable to people affected by those near the epicenter. On Monday, 18 Aug., a magnitude 4.0 earthquake struck the region, the strongest quake felt there since 1996.
Geologists believe the widespread earthquakes could foretell a powerful volcanic eruption coming to the tiny nation.
Earthquakes in Iceland are centered on two major regions of the geologically active nation. The first of these is just to the east of the Bardarbunga caldera, and the second lies near the Dyngjujökull glacier. Magma is running through rock roughly six miles under the surface.
Eyjafjallajokull erupted in 2010, causing over 100,000 flights to be canceled, due to volcanic ash in the air. In addition, airports in the nation were closed for six days, in order to protect the safety of passengers and flight crew. The tiny particles of glass can play havoc with airplanes, and a similar eruption today could threaten airlines throughout Europe.
"Presently there are no signs of eruption, but it cannot be excluded that the current activity will result in an explosive subglacial eruption, leading to an outburst flood (jökulhlaup) and ash emission. The situation is monitored closely," the Met Office of Iceland reported in a statement.
Bardarbunga is the fourth-most active volcano in Iceland, behind Hekla, Grímsvötn, and Katla. The volcano itself last erupted in 1794, and another volcanic event, linked to the volcano's magma supply, took place in 1910. Geologists believe other eruptions may have taken place under the thick ice cover since that time, without being recorded by monitoring devices.
If an eruption does occur at the Bardarbunga volcano, there is little chance of immediate human deaths, as the area surrounding the geological feature is uninhabited. Economic damage is likely to be the greatest threat, as airlines lost $1.7 billion during the 2010 event.
