The eruption series, Iceland's largest eruptions in 230 years that started on August 17, 2014 and lasted for 180 days, under the Bárðarbunga system started with an extremely heavy earthquake swarm followed by clusters of volcanic activity that went on for an extended period. This resulted in multiple lava fountain eruptions in Holuhraun. Lava flow was between 250 and 350 cubic meters per second and came from a dyke over 40 km long. An ice-filled subsidence bowl over 100 square kilometers in area and up to 65 meters deep formed as well. There was very limited ash output from this eruption unlike numerous glacial eruptions which are common in Iceland. The primary concern with this eruption was the large plumes of sulphur dioxide (SO2) in the atmosphere which adversely affected breathing conditions across Iceland, depending on wind direction. The volcanic cloud was also transported toward Western Europe in September 2014.