scholarly journals Erratum: Corrigendum: Crustal movements due to Iceland’s shrinking ice caps mimic magma inflow signal at Katla volcano

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Karsten Spaans ◽  
Sigrún Hreinsdóttir ◽  
Andrew Hooper ◽  
Benedikt Gunnar Ófeigsson
2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Karsten Spaans ◽  
Sigrún Hreinsdóttir ◽  
Andrew Hooper ◽  
Benedikt Gunnar Ófeigsson

Abstract Many volcanic systems around the world are located beneath, or in close proximity to, ice caps. Mass change of these ice caps causes surface movements, which are typically neglected when interpreting surface deformation measurements around these volcanoes. These movements can however be significant and may closely resemble movements due to magma accumulation. Here we show such an example, from Katla volcano, Iceland. Horizontal movements observed by GPS on the flank of Katla have led to the inference of significant inflow of magma into a chamber beneath the caldera, starting in 2000 and continuing over several years. We use satellite radar interferometry and GPS data to show that between 2001 and 2010, the horizontal movements seen on the flank can be explained by the response to the long term shrinking of ice caps and that erratic movements seen at stations within the caldera are also not likely to signify magma inflow. It is important that interpretations of geodetic measurements at volcanoes in glaciated areas consider the effect of ice mass change and previous studies should be carefully reevaluated.


Author(s):  
Ole Bennike ◽  
Anker Weidick

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Bennike, O., & Weidick, A. (1999). Observations on the Quaternary geology around Nioghalvfjerdsfjorden, eastern North Greenland. Geology of Greenland Survey Bulletin, 183, 56-60. https://doi.org/10.34194/ggub.v183.5205 _______________ In North and North-East Greenland, several of the outlet glaciers from the Inland Ice have long, floating tongues (Higgins 1991). Nioghalvfjerdsfjorden (Fig. 1) is today occupied by a floating outlet glacier that is about 60 km long, and the fjord is surrounded by dissected plateaux with broad valleys (Thomsen et al. 1997). The offshore shelf to the east of Nioghalvfjerdsfjorden is unusually broad, up to 300 km wide (Cherkis & Vogt 1994), and recently small low islands were discovered on the western part of this shelf (G. Budeus and T.I.H. Andersson, personal communications 1998). Quaternary deposits are widespread around Nioghalvfjerdsfjorden and include glacial, glaciofluvial, marine, deltaic and ice lake deposits. Ice margin features such as kame deposits and moraines are also common (Davies 1972). The glaciation limit increases from 200 m a.s.l. over the eastern coastal islands to 1000 m in the inland areas; local ice caps and valley glaciers are common in the region, although the mean annual precipitation is only about 200 mm per year. Most of the sea in the area is covered by permanent sea ice, with pack ice further east, but open water is present in late summer in some fjords north of Nioghalvfjerdsfjorden, and in the Nordøstvandet polynia.


Author(s):  
Bjørn Thomassen ◽  
Peter R. Dawes ◽  
Agnete Steenfelt ◽  
Johan Ditlev Krebs

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Thomassen, B., Dawes, P. R., Steenfelt, A., & Krebs, J. D. (2002). Qaanaaq 2001: mineral exploration reconnaissance in North-West Greenland. Geology of Greenland Survey Bulletin, 191, 133-143. https://doi.org/10.34194/ggub.v191.5141 _______________ Project Qaanaaq 2001, involving one season’s field work, was set up to investigate the mineral occurrences and potential of North-West Greenland between Olrik Fjord and Kap Alexander (77°10´N – 78°10´N; Fig. 1). Organised by the Geological Survey of Denmark and Greenland (GEUS) and the Bureau of Minerals and Petroleum (BMP), Government of Greenland, the project is mainly funded by the latter and has the overall goal of attracting the interest of the mining industry to the region. The investigated region – herein referred to as the Qaanaaq region – comprises 4300 km2 of ice-free land centred on Qaanaaq, the administrative capital of Qaanaap (Thule) municipality. Much of the region is characterised by a 500–800 m high plateau capped by local ice caps and intersected by fjords and glaciers. High dissected terrain occurs in Northumberland Ø and in the hinterland of Prudhoe Land where nunataks are common along the margin of the Inland Ice.


2021 ◽  
Author(s):  
Marion Devilliers ◽  
Didier Swingedouw ◽  
Juliette Mignot ◽  
Julie Deshayes ◽  
Gilles Garric ◽  
...  

2019 ◽  
Vol 31 (6) ◽  
pp. 332-344 ◽  
Author(s):  
Jānis Karušs ◽  
Kristaps Lamsters ◽  
Anatolii Chernov ◽  
Māris Krievāns ◽  
Jurijs Ješkins

AbstractThis study presents the first subglacial topography and ice thickness models of the largest ice caps of the Argentine Islands, Wilhelm Archipelago, West Antarctica. During this study, ground-penetrating radar was used to map the thickness and inner structure of the ice caps. Digital surface models of all studied islands were created from aerial images obtained with a small-sized unmanned aerial vehicle and used for the construction of subglacial topography models. Ice caps of the Argentine Islands cover ~50% of the land surface of the islands on average. The maximum thickness of only two islands (Galindez and Skua) exceeds 30 m, while the average thickness of all islands is only ~5 m. The maximum ice thickness reaches 35.3 m on Galindez Island. The ice thickness and glacier distribution are mainly governed by prevailing wind direction from the north. This has created the prominent narrow ice ridges on Uruguay and Irizar islands, which are not supported by topographic obstacles, as well as the elongated shape of other ice caps. The subglacial topography of the ice caps is undulated and mainly dependent on the geological structure and composition of magmatic rocks.


2009 ◽  
Vol 36 (7) ◽  
pp. n/a-n/a ◽  
Author(s):  
Regine Hock ◽  
Mattias de Woul ◽  
Valentina Radić ◽  
Mark Dyurgerov

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