Last update: August 23rd, 2019 at 9:00 am
Iceland’s Bardarbunga volcano has been restless for years, and in August, 2014 an eruption began, sending lava fountains spilling from an old fissure in Holuhraun lava field. The volcano has continued pouring lava and emitting gases since that time, along with continued seismic activity and the subsidence of the caldera.
On November 3, the Icelandic Meteorological Office (IMO) reported 207 earthquakes were detected in the caldera since October 31. Two earthquakes were larger than M 5.0 in strength. They also reported that energy of the geothermal areas in Bardarbunga was a “few hundred megawatts” and the melting of water was estimated about 2 cubic meters per second. Lava continues to flow from the fissure, and the lava field is reported to be about 74 square kilometers (29 square miles).
The IMO also has reported that large quantities of gases have been emitted to the atmosphere, including sulfur dioxide. Sulfur dioxide is implicated in respiratory illness in people and animals exposed to it. It is also implicated in the creation of acid rain, as sulfur dioxide can be converted to sulfuric acid. Sampling of rainwater has been ongoing since late September, and the IMO reported that the pH of rainwater in Iceland, after the start of the Holuhraun eruption, has ranged from pH 3.2 to 7.5 with an average value of pH 5.8. About 40% of the rain is defined as acid rain whereas 60% can be regarded as unpolluted rain. Volcanic gas is not the only factor which influences acidity of rain – other factors include seaspray, geothermal activity, evaporation and fine rock dust.
The Moderate Resolution Imaging Spectroradiometer (MODIS) captured this true-color image on November 4, 2014. The red outline marks the area where the thermal sensors on the instrument detected temperatures higher than background, and marks the area of the Holuhraun lava field.