Importance of Studying Iceland Volcanoes - Research Paper Example

Importance of Studying Iceland volcanoes Abstract Iceland is a country which is famous for volcanoes. In fact hundreds of volcanoes are still active in Iceland because of the geographic peculiarities. Iceland is one of the coldest regions on earth and hence most parts of Iceland are under snow in majority of the periods in a year. Volcanoes are covered by huge blocks of snow and hence while heat energy liberated out of the geothermal activities of Iceland volcanoes are not going directly to the atmosphere. The snows over the volcanoes melted and melted water lakes are formed around the volcanic regions in Iceland. The temperature, area and volume of these melted water lakes will give us important information about the activities of the Iceland volcanoes. Perhaps no other regions in the world have volcanoes under ice blocks and hence the studies of Iceland volcanoes are very much important for the geologists. This paper briefly analyses the importance of Iceland volcanoes. Introduction In Iceland about 30 volcanic systems with hundreds of volcanoes are known active at the present. The most commonly found types in Iceland are composite volcanoes (stratovolcanoes) which are usually part of a chain and spread in vast areas. The age of Iceland’s rocks and lava flows depend on their position on the island. Because of the sea-floor spreading, in the Northwest and in the East of Iceland rocks are older than along the Mid-Atlantic ridge which is situated in the middle (Geology of Iceland) The country, Iceland is famous for volcanoes. In fact, in every year lot of casualties occur in Iceland because of volcano eruption. Grımsvotn is Iceland’s most active volcano at present. One of the peculiar natures of Iceland volcanoes is the difficulty in monitoring whether a volcano is active or not because of the problems in accessing rapid melting of ice and snow during eruption. “Temperate glaciers, such as those in Iceland, are at their pressure melting temperature throughout their thickness and water can migrate beneath the glacier, allowing melt water to flow from a geothermal heat source to the edges of the glacier” (Stewart et al, p.6501). (See appendix 3 for more details about the volcanic zones in Iceland). Traditional methodologies of volcano studies are difficult to use in Iceland volcanoes because of the above problems. In other words, new methodologies needed to be developed in order to learn more about the characteristics of volcanoes in Iceland. Data Discussion: Importance of Studying Iceland volcanoes The proportion of silicic rocks in Iceland is exceptionally high for an oceanic island, representing about 5–10% of the exposed lavas. Together with the geochemical arguments of O- and Th isotope ratios, which are found to be lower in the silicic magmas than in contemporaneous basalts for a given volcano, this strongly suggests a crustal melting origin for the silicic rocks (Martin & Sigmarsson, p.593) Magma productivity in Iceland volcanoes is comparatively higher when we consider the magma productivity of volcanoes in other parts of the world. In other words, the geothermal activities of the Iceland volcanoes are much higher than that of the volcanoes in other regions. At the same time, the magma coming out of volcanic eruptions from Iceland volcanoes consist of numerous precious elements and metals. Martin & Sigmarsson have concluded that “the interaction between the mid-Atlantic idge and a mantle plume beneath Iceland gives rise to high magma productivity, resulting in an elevated geothermal gradient”. In other words, “the lower amphibolitic crust is likely to cross its hydrous solidus at depth and will consequently undergo partial melting, generating silicic magmas within, or close to, the rift-zone (Martin & Sigmarsson, p.604) The information about the Iceland volcanoes were less earlier because of the difficulties in studying these under-snow volcanoes. But for the last couple of decades, new methods were applied to learn more about the Iceland volcanoes which succeeded up to certain extent. The magnitude and direction of plate movements in the Iceland area are now well known. The size and direction of the spreading vector varies slightly from the north to the southern part of the country: At the Tjornes Fracture Zone the total spreading (opening) rate is 1.79 cm/year in the direction N1068E, but 1.85 cm/year in the direction N1048E at the South Iceland Seismic Zone. For Iceland as a whole, the average spreading rate is 1.8 cm/year in the direction N1058E. (GUDMUNDSSON, p.110) Iceland is located in one of the coldest regions of earth and in most of the days during a year, Iceland is facing problems with respect to snow fall and ice accumulation. Because of the Geothermal activities inside the volcanoes in Iceland, the ice or snow surrounding the volcanoes will be melted. This melted ice may form a melted water lake around the proximity of the volcano. The volume and area of the lake may vary depending on the intensity of the activities inside the volcano. Unlike many other volcanoes in the world, the heat liberated out of the volcanoes is not going directly to the atmosphere because of the huge ice coverings over the Iceland volcanoes. The temperatures of the melted water lakes may vary based on the activities of the volcano and it is useful to study how much active the volcano currently is (See appendix 1 and 2 for the comparative temperatures of various melted water lake formed in Iceland as a result of the volcanoes). Crustal deformation and ground inflation are common characteristics of Iceland volcanoes. Even though the crust of the Iceland region is blessed with immense deposits of rocks, the strength of these rocks are comparatively weaker than the rocks seen in other regions of the world. In other words, the rocks seen in Iceland are weaker because of the internal pressure due to the geothermal activities of the volcanoes. In fact the surface of these rocks has irregular shapes because of the above reason. Penal et al after a comprehensive study about the Iceland volcanoes concluded the following things; Measurements of crustal deformation fields on active volcanoes are of prime importance together with seismic monitoring, in order to understand magma movements Ground inflation is a common indicator for magma flow towards shallow depth. However, many factors may influence the deformation signal recorded around volcanoes, including variation in surface loads that can be an important factor. In a general context of climate warming, this phenomenon may become important for ice covered volcanoes (Penal et al, p.337) Climate warming is happening because of the melted water lakes. The water in these water lakes are extremely hot because of the internal activities and hence the regions around the volcanoes would be hot even though the climate happens to be extremely cold on other parts. Conclusions Iceland volcanoes are entirely different from volcanoes seen in other parts of the world. The huge ice blocks over the Iceland volcanoes will be melted and water lakes with hot water will be formed within the proximities of the volcanoes. The measure of the temperatures of this lake water will give some idea about the activities of the volcanoes in the near proximity. Works Cited 1. Gudmundsson, Agust. “DYNAMICS OF VOLCANIC SYSTEMS IN ICELAND: Example of Tectonism and Volcanism at Juxtaposed Hot Spot and Mid-Ocean Ridge Systems.”2000. Annu. Rev. Earth Planet. Sci. 2000. 28:107–40 Copyright q 2000 by Annual Reviews. 2. “Geology of Iceland.”Web. 23 November 2010. 3. Martin E & Sigmarsson O. “Crustal Thermal State and Origin of Silicic Magma in Iceland: The Case of Torfajo¨ kull, Ljo´ sufjo¨ ll and Snæfellsjo¨ kull Volcanoes”.2007. Contrib Mineral Petrol (2007). 153: p. 593–605. DOI 10.1007/s00410-006-0165-5 4. Pinel,V. Sigmundsson,F.Sturkell,E. Geirsson,H. Einarsson,P. Gudmundsson M.T. and Ognad´ottir T.H. “Discriminating Volcano Deformation Due To Magma Movements and Variable Surface Loads: Application to Katla Subglacial Volcano”. 2007. Iceland. Geophys. J. Int. (2007). 169, 325–338. doi: 10.1111/j.1365-246X.2006.03267.x 4. STEWART, S. F. PINKERTON, H. BLACKBURN G. A. and GUDMUNDSSON M. T. “Monitoring Active Subglacial Volcanoes: A Case Study Using Airborne Remotely”. 2008. Sensed Imagery of Grı´msvo¨tn, Iceland International Journal of Remote Sensing Vol. 29, No. 22, 20 November 2008, DOI: 10.1080/01431160802168186. p. 6501–6514 Appendix 1 (Stewart et al, p.6510) Appendix 2 Histogram of temperatures within the Grı´msvo¨ tn 1998 crater lake for 10 and 14 June 2001 (Stewart et al, p.6505) Appendix 3 (a) A map of Iceland with the volcanic zones and location of Vatnajo¨ kull ice sheet, (b) the location of Grı´msvo¨ tn in relation to the Vatnajo¨ kull ice sheet, and (c) a contour map of the Grı´msvo¨ tn caldera created in 2001 by Icelandic collaborators, using differential GPS. The Grı´msfjall ridge, crater lake, and the 1998 eruption site are labelled. The rectangular box over the Grı´msfjall ridge shows the land area covered by the aerial survey. (Stewart et al, p.6502). Read More