Most active Volcanic Region
Iceland is the most active volcanic region on Earth located in the Atlantic ocean between Greenland and Norway. It is a landmass that is part of a much larger entity situated at the junction of two large submarine structures, the Mid-Atlantic ridge and the Greenland-Iceland Faeroes Ridge. Iceland is located where the Asthenospheric flow under the north east Atlantic plate boundary interacts and mixes with a deep seated mantle plume. The buoyancy of the Iceland plume leads to dynamic uplift of the Iceland plateau and high volcanic productivity over the plume produces a thick crust.
Iceland is one of the most active volcanic regions on Earth where almost all types of volcanic and geothermal activity can be found. The volcanism on Iceland is the contribution from both the Iceland plume hotspot activity and the Mid Atlantic Ridge activity. The Mid Atlantic Ridge as the name indicates is the ridge forming from volcanism in Atlantic ocean but however it is also visible on land. Iceland's landscapes are forged by the processes of volcanism. The volcanic landscapes include rift valleys, geysers, hot springs, rhyolite mountains, columnar basalt formations, lava fields and lunar like craters. Subglacial volcanism has created table mountains in northern and southern Iceland. Iceland sits spanning the Mid Atlantic Ridge tectonic plate boundary which separates the Eurasian and the North American plates. The ridge, and underwater mountain chain extended about 16,000 km along the north-south axis of the Atlantic ocean. A rift valley running along its spine is formed by plate tectonics and it's the locus of new crust formation. Molten lava from beneath the Earth's crust constantly comes up, cools and is pushed away from the ridge flanks which widen the gap between continents in the process. Iceland formed by the coincidence of the spreading boundary of the North American and Eurasian plate with a hotspot or mantle plume. As the plates moved apart, excessive eruptions of lava constructed volcanoes and filled the rift valleys. Subsequent movement rifted these later lava fields causing long valleys bounded by parallel faults. The divergence of the ridge started in the north about 150 million years ago and 90 million years ago in the south. These movements continue today accompanied by earthquake, reactivation of old volcanoes and creation of new ones.
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| Stokkur Geyser, Iceland |
Strokkur is located less than 100 metre away from Geysir and it erupts frequently every 4 to 8 minutes. Strokkur is a fountain geyser. It is one of the very few geysers that erupts regularly spouting steaming water up to 20 meters.
Why do geysers occur?
Well geysers occur in high temperature geothermal areas within the zone of active rifting and volcanism where temperature in the subsurface sis higher than 200 Celsius at less than 1 km depth. The temperature of the hot springs is up to 100 Celsius and some are constantly boiling. If the temperature at depth rises above boiling, the hot springs erupt which means that they are geysers. Geysers eruption occurs when boiling water within the geyser trapped by cooler water above it explodes forcing its way to the surface.
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| Katla volcano, Iceland |
Katla volcano is located near the southern end of Iceland's eastern volcanic zone and is hidden beneath the Myrdalsjökull icecap. Katla is one of Iceland's most active and most dangerous volcanoes, infamous for its large eruptions happening on average every 50-100 year causing devastating glacial floods. Well its been quiet now for a long time but in recent year, increased seismicity and inflation of Katla has been measured. Katla statistically due for a new eruption but an eruption is not too distant would not come as a big surprise.