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Identification of Active Volcanic Polygons in Iceland

Iceland is divided into several volcanic zones and belts. Here, a division method according to numbers of polygons is introduced.

Numbers of volcanically active polygons in Iceland

(1) This polygon comprises half of Reykjanes Oblique Rift Zone (RORZ). The western corner connects with the Reykjanes Ridge. (2) The other half of RORZ. The eastern corner connects with the South Iceland Seismic Zone. (3) The southern half of the Western Volcanic Zone. The rifting process is mainly found within the eastern half of the polygon. The Rift Valley of Thingvellir is found there. (4) The northern half of the WVZ. Langjökull Glacier covers a large part of this section. (5) This polygon is a volcanic belt on its own. Formerly, it was the southern end of a much longer volcanic zone extending to Skagafjordur, but that part was replaced by the North Volcanic Zone. (6) The southern part of the South Iceland Volcanic Belt, which contains the Westman Islands. (7) The northern part of the SIVB with Eyjafjallajökull and Katla. Hekla is located on the northern corner of the polygon. (8) The southernmost part of the Eastern Volcanic Zone. The rifting process perpendicular to tectonic drift appears very clearly, and magma is mainly provided horizontally from the adjacent polygons, for instance from Grímsvötn, Bárdarbunga or Katla caldera. (9) The central polygon of the EVZ, filled with powerful volcanic systems. It has adjacent mini polygons of Kverkfjöll and Grímsvötn, and the side system of Tungnafellsjökull. In the middle, Bárdarbunga has played a big role, responsible for the Holuhraun eruption. (11) The southernmost polygon of the North Volcanic Zone. It is actually the turning part between the EVZ and the NVZ, and the pattern forming the polygons becomes less distinct along this latitude. Askja is found in the center of the area. (12) This polygon of Hrúthálsar volcanic site is the central part of NVZ. It is perhaps a bit remote and has not been active recently, so it is not a famous volcanic site. (13) The southern side of the polygon forms a hub for the volcanic and geothermal areas near Lake Mývatn. The northern corner marks the end of the NVZ, It connects with the Grímsey Oblique Rift in the north. (14) This is the southern half of the Öræfajökull Volcanic Belt. It is a bit outside the main volcanic formations of Iceland and is entirely located within the Eurasian Tectonic Plate area. (15) The northern half of the ÖVB, with Snæfell Volcano at the northern end. Snæfell is also curiously a counterpart of Snæfellsjökull in the west of Iceland, found exactly on the same latitude, and in the same context with the mantle convection rolls system (although mirrored). (16) The eastern roots of the Snæfellsnes Volcanic Belt. The Ljósufjöll Volcanic System extends through the area. (17) The central part of SVB, marking the location of Lýsufjöll Volcanic System. (18) The western most part of SVB, with Snæfellsjökull at the western end, being the western outpost of Icelandic Volcanoes, and as mentioned before, the counterpart of the eastern outposts of Icelandic Volcanoes, Snæfell. The Grímsey Oblique Rift has a few volcanic systems, but the polygon system is quite tight at that latitude, so no numbers are given to that area here. The Reykjanes Ridge follows a line, rather than polygons, so it is not included in this numerical system either. Many mini polygons must be analyzed separately but are not included here to maintain some degree of clarity.

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