A brief but sharp earthquake swarm was detected in Öræfajökull, one of Iceland's most powerful volcanoes shortly before midnight, yesterday Monday. Two relatively powerful 3+ quakes were detected in the caldera of the volcano, both at 23:15.
Iceland's second deadliest volcano
According to the Seismic Monitoring System of the IMO the epicenter of yesterday's quakes was in the southeastern part of the volcano's caldera. A 3.1 magnitude quake was detected at a depth of only 100 m (330 ft), 3.4 km (2.1 mi) SE of Hvannadalshnjúkur peak, and a second 3.2 magnitude quake at a depth of 1.1 km (0.7 mi) sp,e 4.5 km (2.8 mi) East-Southeast of Hvannadalshnjúkur peak.
Historically earthquakes have been extremely rare in Öræfajökull, but recently it has been showing significantly greater levels of activity. The last 3+ magnitude quake was recorded on the 22nd of September. Scientists have argued that the seismic activity in the volcano's caldera is similar to the activity shown by Eyjafjallajökull volcano in the lead-up to the 2010 eruption, and is caused by movements of magma from the mantle up into the earth's crust and into the volcano.
It should be stressed that it could take a decade for a volcano to erupt after it starts showing signs of magma movements, and it is possible for volcanoes to stir like this, only to lapse back into slumber.
Read more: Öræfajökull: Iceland's second deadliest volcano
Öræfajökull is the southernmost part of Vatnajökull glacier. Its summit, Hvannadalshnjúkur, is the tallest peak in Iceland, standing at an elevation of 2,110 meters (6.920 ft). Öræfajökull glacier covers a giant volcano which last erupted in 1727. Following this eruption the volcano was completely dormant until a couple of years ago when it started to show activity again.
Öræfajökull erupts in steam-blast eruptions, also known as phreatic eruptions. In addition to the 1727 eruption it has erupted only once since Iceland was settled in the Viking Age. In 1362 Öræfajökull erupted in the second deadliest eruption in Icelandic history, destroying one of the most prosperous farmland regions in South Iceland, killing all inhabitants and livestock at 20-40 farms.
The volcano is not particularly active, erupting at an interval of several hundred years. The 1362 eruption is considered to be the largest tepthra eruption in the world in the last 1000 years.
A brief but sharp earthquake swarm was detected in Öræfajökull, one of Iceland's most powerful volcanoes shortly before midnight, yesterday Monday. Two relatively powerful 3+ quakes were detected in the caldera of the volcano, both at 23:15.
Iceland's second deadliest volcano
According to the Seismic Monitoring System of the IMO the epicenter of yesterday's quakes was in the southeastern part of the volcano's caldera. A 3.1 magnitude quake was detected at a depth of only 100 m (330 ft), 3.4 km (2.1 mi) SE of Hvannadalshnjúkur peak, and a second 3.2 magnitude quake at a depth of 1.1 km (0.7 mi) sp,e 4.5 km (2.8 mi) East-Southeast of Hvannadalshnjúkur peak.
Historically earthquakes have been extremely rare in Öræfajökull, but recently it has been showing significantly greater levels of activity. The last 3+ magnitude quake was recorded on the 22nd of September. Scientists have argued that the seismic activity in the volcano's caldera is similar to the activity shown by Eyjafjallajökull volcano in the lead-up to the 2010 eruption, and is caused by movements of magma from the mantle up into the earth's crust and into the volcano.
It should be stressed that it could take a decade for a volcano to erupt after it starts showing signs of magma movements, and it is possible for volcanoes to stir like this, only to lapse back into slumber.
Read more: Öræfajökull: Iceland's second deadliest volcano
Öræfajökull is the southernmost part of Vatnajökull glacier. Its summit, Hvannadalshnjúkur, is the tallest peak in Iceland, standing at an elevation of 2,110 meters (6.920 ft). Öræfajökull glacier covers a giant volcano which last erupted in 1727. Following this eruption the volcano was completely dormant until a couple of years ago when it started to show activity again.
Öræfajökull erupts in steam-blast eruptions, also known as phreatic eruptions. In addition to the 1727 eruption it has erupted only once since Iceland was settled in the Viking Age. In 1362 Öræfajökull erupted in the second deadliest eruption in Icelandic history, destroying one of the most prosperous farmland regions in South Iceland, killing all inhabitants and livestock at 20-40 farms.
The volcano is not particularly active, erupting at an interval of several hundred years. The 1362 eruption is considered to be the largest tepthra eruption in the world in the last 1000 years.
