Ice‐volcano interactions during the 2010 Eyjafjallajökull eruption, as revealed by airborne imaging radar
Tóm tắt
During the eruption of the ice‐covered Eyjafjallajökull volcano, a series of images from an airborne Synthetic Aperture Radar (SAR) were obtained by the Icelandic Coast Guard. Cloud obscured the summit from view during the first three days of the eruption, making the weather‐independent SAR a valuable monitoring resource. Radar images revealed the development of ice cauldrons in a 200 m thick ice cover within the summit caldera, as well as the formation of cauldrons to the immediate south of the caldera. Additionally, radar images were used to document the subglacial and supraglacial passage of floodwater to the north and south of the eruption site. The eruption breached the ice surface about four hours after its onset at about 01:30 UTC on 14 April 2010. The first SAR images, obtained between 08:55 and 10:42 UTC, show signs of limited supraglacial drainage from the eruption site. Floodwater began to drain from the ice cap almost 5.5 h after the beginning of the eruption, implying storage of meltwater at the eruption site due to initially constricted subglacial drainage from the caldera. Heat transfer rates from magma to ice during early stages of cauldron formation were about 1 MW m−2 in the radial direction and about 4 MW m−2 vertically. Meltwater release was characterized by accumulation and drainage with most of the volcanic material in the ice cauldrons being drained in hyperconcentrated floods. After the third day of the eruption, meltwater generation at the eruption site diminished due to an insulating lag of tephra.
Từ khóa
Tài liệu tham khảo
Björnsson H., 2002, Subglacial lakes and jökulhlaups in Iceland, Global Planet. Change, 35, 255
Björnsson H., 2000, Surface and bedrock topography of the Mýrdalsjökull ice cap, Iceland: The Katla caldera, eruption sites and routes of jökulhlaups, Jökull, 49, 29, 10.33799/jokull2000.49.029
Elachi C., 1987, Introduction to Physics and Techniques of Remote Sensing
Gröndal G. O., 2005, Hættumat vegna eldgosa og hlaupa frá vestanverðum Mýrdalsjökli og Eyjafjallajökli [Risk Assessments on Eruptions and Jökulhlaups From the Western Part of Mýrdalsjökull and Eyjafjallajökull], 105
Gudmundsson M. T., 2005, Hættumat vegna eldgosa og hlaupa frá vestanverðum Mýrdalsjökli og Eyjafjallajökli [Risk Assessments on Eruptions and Jökulhlaups From the Western Part of Mýrdalsjökull and Eyjafjallajökull], 11
Jóhannesson T., 2011, LiDAR mapping of the Snæfellsjökull ice cap, western Iceland, Jökull, 61, 19, 10.33799/jokull2011.61.019
Larsen G.(1999) Gosið í Eyjafjallajökli 1821–23. Stutt samantekt á framvindu og áhrifum gossins samkvæmt lýsingum [The eruption of Eyjafjallajökull 1821–23. A short summary of course of events and effects based on contemporary accounts] RH‐28‐99 14 pp. Sci. Inst. Reykjavik.
Larsen G., 2000, Holocene eruptions within the Katla volcanic system, south Iceland: Characteristics and environmental impact, Jökull, 49, 1, 10.33799/jokull2000.49.001
Loughlin S. C., 2002, Volcano Ice Interactions on Earth and Mars, 149
Óskarsson B. V.(2008) The Skerin ridge on Eyjafjallajökull south Iceland: Morphology and magma‐ice interaction in an ice‐confined silicic fissure eruption MS thesis Univ. of Iceland Reykjavik.
Paterson W. S. B., 2006, The Physics of Glaciers
Rist S., 1981, Jöklabreytingar [Glacier variations] 1964/65–1973/74(10 ár), 1974/75–1977/78(4 ár) og 1978/79, Jökull, 31, 37, 10.33799/jokull1981.31.037o
Roberts M. J. G.Sigurðsson O.Sigurðsson E.Pagneux T.Jóhannesson S.Zóphóníasson M. T.Guðmundsson A. J.Russell Á. G.Gylfason andF.Höskuldsson(2011) The April 2010 eruption of Eyjafjallajökull volcano: Glacial flooding and attendant hazards abstract V18S1‐1330 presented at XXV IUGG General Assembly Melbourne Vic. Australia 28 June to 7 July.
Strachan S. M.(2001) A geophysical investigation of the Eyjafjallajökull glaciovolcanic system South Iceland using radio echo sounding PhD thesis Dep. of Geogr. Univ. of Edinburgh Edinburgh U. K.
Vallance J. W., 2000, Encyclopedia of Volcanoes, 601
Wilson L., 2002, Ice‐Volcano Interaction on Earth and Mars, 5