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Combination of SAR remote sensing and GIS for monitoring subglacial volcanic activity – recent results from Vatnaj kull ice cap (Iceland)
K. Scharrer,R. Malservisi,Ch. Mayer,O. Spieler
Natural Hazards and Earth System Sciences (NHESS) & Discussions (NHESSD) , 2007,
Abstract: This paper presents latest results from the combined use of SAR (Synthetic Aperture Radar) remote sensing and GIS providing detailed insights into recent volcanic activity under Vatnaj kull ice cap (Iceland). Glaciers atop active volcanoes pose a constant potential danger to adjacent inhabited regions and infrastructure. Besides the usual volcanic hazards (lava flows, pyroclastic clouds, tephra falls, etc.), the volcano-ice interaction leads to enormous meltwater torrents (icelandic: j kulhlaup), devastating large areas in the surroundings of the affected glacier. The presented monitoring strategy addresses the three crucial questions: When will an eruption occur, where is the eruption site and which area is endangered by the accompanying j kulhlaup. Therefore, sufficient early-warning and hazard zonation for future subglacial volcanic eruptions becomes possible, as demonstrated for the Bardárbunga volcano under the northern parts of Vatnaj kull. Seismic activity revealed unrest at the northern flanks of Bardárbunga caldera at the end of September 2006. The exact location of the corresponding active vent and therefore a potentially eruptive area could be detected by continuous ENVISAT-ASAR monitoring. With this knowledge a precise prediction of peri-glacial regions prone to a devastating outburst flood accompanying a possible future eruption is possible.
Modelling the 20th and 21st century evolution of Hoffellsj kull glacier, SE-Vatnaj kull, Iceland  [PDF]
G. Aealgeirsdóttir,S. Guemundsson,H. Bj?rnsson,F. Pálsson
The Cryosphere , 2011, DOI: 10.5194/tc-5-961-2011
Abstract: The Little Ice Age maximum extent of glaciers in Iceland was reached about 1890 AD and most glaciers in the country have retreated during the 20th century. A model for the surface mass balance and the flow of glaciers is used to reconstruct the 20th century retreat history of Hoffellsj kull, a south-flowing outlet glacier of the ice cap Vatnaj kull, which is located close to the southeastern coast of Iceland. The bedrock topography was surveyed with radio-echo soundings in 2001. A wealth of data are available to force and constrain the model, e.g. surface elevation maps from ~1890, 1936, 1946, 1989, 2001, 2008 and 2010, mass balance observations conducted in 1936–1938 and after 2001, energy balance measurements after 2001, and glacier surface velocity derived by kinematic and differential GPS surveys and correlation of SPOT5 images. The approximately 20% volume loss of this glacier in the period 1895–2010 is realistically simulated with the model. After calibration of the model with past observations, it is used to simulate the future response of the glacier during the 21st century. The mass balance model was forced with an ensemble of temperature and precipitation scenarios derived from 10 global and 3 regional climate model simulations using the A1B emission scenario. If the average climate of 2000–2009 is maintained into the future, the volume of the glacier is projected to be reduced by 30% with respect to the present at the end of this century. If the climate warms, as suggested by most of the climate change scenarios, the model projects this glacier to almost disappear by the end of the 21st century. Runoff from the glacier is predicted to increase for the next 30–40 yr and decrease after that as a consequence of the diminishing ice-covered area.
Modelling the 20th and 21st century evolution of Hoffellsj kull glacier, SE-Vatnaj kull, Iceland  [PDF]
G. Aealgeirsdóttir,S. Guemundsson,H. Bj?rnsson,F. Pálsson
The Cryosphere Discussions , 2011, DOI: 10.5194/tcd-5-1055-2011
Abstract: The Little Ice Age maximum extent of glaciers in Iceland was reached about 1890 AD and most glaciers in the country have retreated during the 20th century. A model for the surface mass balance and the flow of glaciers is used to reconstruct the 20th century retreat history of Hoffellsj kull, a south-flowing outlet glacier of Vatnaj kull, which is located close to the southeast coast of Iceland. The bedrock topography was surveyed with radio-echo soundings in 2001. A wealth of data are available to force and constrain the model, e.g. surface elevation maps from ~1890, 1936, 1946, 1986, 2001, 2008 and 2010, mass balance observations conducted in 1936–1938 and after 2001, energy balance measurements after 2001, and glacier surface velocity derived by DGPS and correlation of SPOT5 images. The 21% volume loss of this glacier in the period 1895–2010 is realistically simulated with the model. After calibration of the model with past observations, it is used to simulate the future response of the glacier during the 21st century. The mass balance model was forced with an ensemble of temperature and precipitation scenarios from a study of the effect of climate change on energy production in the Nordic countries (the CES project). If the average climate of 2000–2009 is maintained into the future, the volume of the glacier is projected to be reduced by 30% with respect to the present at the end of this century, and the glacier will almost disappear if the climate warms as suggested by most of the climate change scenarios. Runoff from the glacier is predicted to increase for the next 30–40 years and decrease after that as a consequence of the diminishing ice-covered area.
Eyjafjallaj kull Volcano Eruption – A Brief Approach
OROIAN I.
Proenvironment Promediu , 2010,
Abstract: The paper summarizes the main aspects of the Eyjafjallaj kull volcano eruption in Iceland. The process ispresented in the context of Iceland location on tectonic plates’ distribution. Aspects concerning Eyjafjallaj kull positionon volcanic landscape of Iceland, both eruption phases and ash composition are briefly described. There are alsoemphasized the effects of the event on main common life aspects it affected (aircraft in Europe and farming in Iceland).The influence of the volcano eruption on the climate change is also discussed.
Sulphur dioxide as a volcanic ash proxy during the April–May 2010 eruption of Eyjafjallaj kull Volcano, Iceland
H. E. Thomas,A. J. Prata
Atmospheric Chemistry and Physics (ACP) & Discussions (ACPD) , 2011,
Abstract: The volcanic ash cloud from the eruption of Eyjafjallaj kull volcano in April and May 2010 resulted in unprecedented disruption to air traffic in Western Europe causing significant financial losses and highlighting the importance of efficient volcanic cloud monitoring. The feasibility of using SO2 as a tracer for the ash released during the eruption is investigated here through comparison of ash retrievals from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) with SO2 measurements from a number of infrared and ultraviolet satellite-based sensors. Results demonstrate that the eruption can be divided into an initial ash-rich phase, a lower intensity middle phase and a final phase where considerably greater quantities both ash and SO2 were released. Comparisons of ash-SO2 dispersion indicate that despite frequent collocation of the two species, there are a number of instances throughout the eruption where separation is observed. This separation occurs vertically due to the more rapid settling rate of ash compared to SO2, horizontally through wind shear and temporally through volcanological controls on eruption style. The potential for the two species to be dispersed independently has consequences in terms of aircraft hazard mitigation and highlights the importance of monitoring both species concurrently.
Response of Eyjafjallaj kull, Torfaj kull and Tindfjallaj kull ice caps in Iceland to regional warming, deduced by remote sensing
Sverrir Gudmundsson,Helgi Bj?rnsson,Eyjólfur Magnússon,Etienne Berthier
Polar Research , 2011, DOI: 10.3402/polar.v30i0.7282
Abstract: We assess the volume change and mass balance of three ice caps in southern Iceland for two periods, 1979–1984 to 1998 and 1998 to 2004, by comparing digital elevation models (DEMs). The ice caps are Eyjafjallaj kull (ca. 81 km2), Tindfjallaj kull (ca. 15 km2) and Torfaj kull (ca. 14 km2). The DEMs were compiled using aerial photographs from 1979 to 1984, airborne Synthetic Aperture Radar (SAR) images obtained in 1998 and two image pairs from the SPOT 5 satellite's high-resolution stereoscopic (HRS) instrument acquired in 2004. The ice-free part of the accurate DEM from 1998 was used as a reference map for co-registration and correction of the vertical offset of the other DEMs. The average specific mass balance was estimated from the mean elevation difference between glaciated areas of the DEMs. The glacier mass balance declined significantly between the two periods: from 0.2 to 0.2 m yr 1 w. eq. during the earlier period (1980s through 1998) to 1.8 to 1.5 m yr 1 w. eq. for the more recent period (1998–2004). The declining mass balance is consistent with increased temperature over the two periods. The low mass balance and the small accumulation area ratio of Tindfjallaj kull and Torfaj kull indicate that they will disappear if the present-day climate continues. The future lowering rate of Eyjafjallaj kull will, however, be influenced by the 2010 subglacial eruption in the Eyjafjallaj kull volcano.
Surface Morphology of Basalt Columns at Svartifoss, Vatnaj?kulsTjóegareur, Southern Iceland  [PDF]
Lawrence H. Tanner
Journal of Geological Research , 2013, DOI: 10.1155/2013/482067
Abstract: A spectacular example of columnar-jointed basalt occurs at Svartifoss in the Vatnaj?kull National Park of southern Iceland. The columns are notable for a variety of features on the vertical joint surfaces and the horizontal parting surfaces. The jointed surfaces of the columns display horizontal striations at a spacing of centimeters to decimeters. The individual striations exhibit crescentic hackles with a plumose pattern, the orientation of which varies between adjacent striations. Also present are gently dipping, millimeter-scale laminations not previously described. Horizontal parting surfaces of the columns display a circular ring that inscribes most of the diameter column. The ring features alternately positive or negative relief against the perimeter of the column and exhibits a radiating pattern of hackles originating at the center of the ring. Petrographic examination reveals that the basalt contains an interlocking network of plagioclase laths preferentially aligned perpendicular to the column axes. The circular features have been described previously and attributed to late-stage melt migration driven by a load-induced pressure gradient. The striations were formed from stepwise, downward propagation of the polygonal fracture system, and the plumose structures were formed from tensile stresses during fracture propagation. The small-scale laminations may result from preferential grain alignment of plagioclase laths. 1. Introduction Columnar-jointed basalts, which have been found on all continents, are among the most widely recognizable features of basalt volcanism. Indeed, often they are one of the first igneous features to be correctly identified by students in introductory geology classes. The textbooks used in such classes ascribe the formation of columnar jointing to the volume change (contraction) of flows or shallow intrusions as they cool from the top down (e.g., see [1]). These simplistic explanations are more or less correct at a very basic level, but they do nothing to explain why cooling and the consequent volume changes cause the formation of a regular fracture pattern. In great part, this lack of specificity is derived from the lack of widespread agreement among igneous petrologists themselves on a precise mechanism of formation since their interpretation by Mallet [2]. Subsequent contributions include those of James [3], Tomkeieff [4], Spry [5], Jaeger [6], Peck and Minakami [7], Reiter et al. [8], and Aydin and DeGraff [9]. Goehring et al. [10] used corn-starch analog experiments to derive a scaling law that applies to contraction
Katla volcano in Iceland, potential hazards and risk assessment  [PDF]
Jónas Elíasson
Natural Science (NS) , 2014, DOI: 10.4236/ns.2014.63014
Abstract:

Katla in Iceland is one of the famous volcanoes of the world for the ferocity of the eruptions and associated j?kulhlaups. The major potential hazards are the j?kulhlaup floods that can hit three different floodplains, an associated tsunami that can harass the south coast of Iceland and a volcanic ash cloud that endangers civil aviation on an unknown scale. The eruption probabilities in Katla and the two others known eruption sectors of the Myrdalsj?kull glacier are reassessed and a 2013 risk curve for the next eruption in Katla is found. The probability of tsunami heights is estimated and the risk from other tsunami sources in the Atlantic Ocean is included. For the danger to aviation, two classes of eruption are defined: an EYF (EYjaFjallaj?kull) eruption class that does not produce volcanic plumes that are dangerous for air traffic in Europe, and another stronger class, the KAT (KATla) class, producing plumes that most likely are dangerous for air traffic in Europe. Overall probabilities for an EYF class eruption in next year and a KAT class eruption in the next 5 years are estimated.

SO2 and BrO observation in the plume of the Eyjafjallaj kull volcano 2010: CARIBIC and GOME-2 retrievals
K.-P. Heue, C. A. M. Brenninkmeijer, A. K. Baker, A. Rauthe-Sch ch, D. Walter, T. Wagner, C. H rmann, H. Sihler, B. Dix, U. Frie , U. Platt, B. G. Martinsson, P. F. J. van Velthoven, A. Zahn,R. Ebinghaus
Atmospheric Chemistry and Physics (ACP) & Discussions (ACPD) , 2011,
Abstract: The ash cloud of the Eyjafjallaj kull (also referred to as: Eyjafjalla (e.g. Schumann et al., 2011), Eyjafj ll or Eyjafjoll (e.g. Ansmann et al., 2010)) volcano on Iceland caused closure of large parts of European airspace in April and May 2010. For the validation and improvement of the European volcanic ash forecast models several research flights were performed. Also the CARIBIC (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container) flying laboratory, which routinely measures at cruise altitude (≈11 km) performed three dedicated measurements flights through sections of the ash plume. Although the focus of these flights was on the detection and quantification of the volcanic ash, we report here on sulphur dioxide (SO2) and bromine monoxide (BrO) measurements with the CARIBIC DOAS (Differential Optical Absorption Spectroscopy) instrument during the second of these special flights on 16 May 2010. As the BrO and the SO2 observations coincide, we assume the BrO to have been formed inside the volcanic plume. Average SO2 and BrO mixing ratios of ≈40 ppb and ≈5 ppt respectively are retrieved inside the plume. The BrO to SO2 ratio retrieved from the CARIBIC observation is ≈1.3×10 4. Both SO2 and BrO observations agree well with simultaneous satellite (GOME-2) observations. SO2 column densities retrieved from satellite observations are often used as an indicator for volcanic ash. As the CARIBIC O4 column densities changed rapidly during the plume observation, we conclude that the aerosol and the SO2 plume are collocated. For SO2 some additional information on the local distribution can be derived from a comparison of forward and back scan GOME-2 data. More details on the local plume size and position are retrieved by combining CARIBIC and GOME-2 data.
SO2 and BrO observation in the plume of the Eyjafjallaj kull volcano 2010: CARIBIC and GOME-2 retrievals  [PDF]
K.-P. Heue,C. A. M. Brenninkmeijer,A. K. Baker,A. Rauthe-Sch?ch
Atmospheric Chemistry and Physics (ACP) & Discussions (ACPD) , 2011, DOI: 10.5194/acp-11-2973-2011
Abstract: The ash cloud of the Eyjafjallaj kull (also referred to as: Eyjafjalla (e.g. Schumann et al., 2011), Eyjafj ll or Eyjafjoll (e.g. Ansmann et al., 2010)) volcano on Iceland caused closure of large parts of European airspace in April and May 2010. For the validation and improvement of the European volcanic ash forecast models several research flights were performed. Also the CARIBIC (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container) flying laboratory, which routinely measures at cruise altitude (≈11 km) performed three dedicated measurements flights through sections of the ash plume. Although the focus of these flights was on the detection and quantification of the volcanic ash, we report here on sulphur dioxide (SO2) and bromine monoxide (BrO) measurements with the CARIBIC DOAS (Differential Optical Absorption Spectroscopy) instrument during the second of these special flights on 16 May 2010. As the BrO and the SO2 observations coincide, we assume the BrO to have been formed inside the volcanic plume. Average SO2 and BrO mixing ratios of ≈40 ppb and ≈5 ppt respectively are retrieved inside the plume. The BrO to SO2 ratio retrieved from the CARIBIC observation is ≈1.3×10 4. Both SO2 and BrO observations agree well with simultaneous satellite (GOME-2) observations. SO2 column densities retrieved from satellite observations are often used as an indicator for volcanic ash. As the CARIBIC O4 column densities changed rapidly during the plume observation, we conclude that the aerosol and the SO2 plume are collocated. For SO2 some additional information on the local distribution can be derived from a comparison of forward and back scan GOME-2 data. More details on the local plume size and position are retrieved by combining CARIBIC and GOME-2 data.
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