MarketIce cauldron
Company Profile

Ice cauldron

Ice cauldrons are ice formations within glaciers that cover some subglacial volcanoes. They can have circular to oblong forms. Their surface areas reach from some meters to up to 1 or more kilometers.

Formation and continued existence of ice cauldrons
Ice cauldrons and subglacial eruptions When an eruption takes place under a bigger glacier, e.g. an ice cap, it normally begins with an effusive stage. The heat forms an ice cave and pillow lava is produced. After some time, the eruption has reached a stage where the pressure drops within the ice vault and the eruption style changes to become explosive. Hyaloclastite is produced and the heat is transferred to the meltwater. "At this stage, the surface ice begins to act brittle and creates concentric fractures that cave in towards the meltwater reservoir. This is referred to as the ice cauldron". When the eruption continues, “the meltwater reservoir becomes so large that the ice cauldron collapses inward towards the edifice, exposing the meltwater reservoir and allowing the breach of both the reservoir and the explosive lava, releasing plumes of gasses and jets of hyaloclastites“. Ice cauldrons on top of subglacial geothermal areas Another case are ice cauldrons situated on top of geothermal areas. "(…) hydrothermal systems are created that bring heat up from a magma body, continuously melting ice into water that may be stored at the glacier bed until it breaks out in jökulhlaups". Many examples for a decades long existence of such ice cauldrons are to be found in Iceland. ==Ice cauldrons around the world==
Ice cauldrons around the world
Examples from Iceland . Skaftá cauldrons as slight identations to the east of Hamarinn. Skaftárkatlar (Skaftá cauldrons) These are two depressions in the ice cover above two subglacial lakes in the south-western part of Vatnajökull. In the whole, many cauldrons are to be found within Vatnajökull glacier ( in 2015), the largest of which in the western part of the ice cap are the Skaftá cauldrons. These ice cauldrons "are created by melting at subglacial geothermal areas". The meltwater accumulates in lakes "under the cauldrons until it drains every 2–3 years in a jökulhlaup" of normally up to . Katla Famous examples from Iceland are the ice cauldrons within the Katla caldera. Katla is an important caldera and central volcano situated under the Mýrdalsjökull glacier cap in the southern part of Iceland's East Volcanic Zone. 150–200 eruptions during Holocene have been attributed to Katla, and 17 of these happened since Settlement of Iceland in the 8th century. Most of the eruptions had their origin in the ice covered caldera. The last large eruption took place in 1918 and was associated with a jökulhlaup with an estimated peak discharge of about . Others have also documented the change with time of ice cauldrons at Katla. Ice cauldrons in other environments , Alaska Ice cauldrons of course do not form only in Iceland, but also at many other places where there is subglacial volcanic activity, e.g. in Alaska (Mount Redoubt, Mount Spurr). == Ice cauldrons and volcano monitoring ==
Ice cauldrons and volcano monitoring
As deepening and widening of the ice cauldrons at Katla volcano, and especially in combination with increased seismic activity, are interpreted as signs of magma inflow, the cauldrons are closely monitored. == See also ==
tickerdossier.comtickerdossier.substack.com