The Volume of the Tunguhraun and Dvergagígahraun Lavas, Central Iceland

• Main Author: Julia Annina Heilig 1990-
• Other Authors: Háskóli Íslands
• Format: Thesis
• Language: English
• Published: 2021
• Subjects: Jarðfræði; Hraun; Tungnafellsjökull; glacier; Iceland
• Online Access: http://hdl.handle.net/1946/38559

The Tunguhraun and Dvergagígahraun lavas are two lava fields in the central highland of Iceland. They are the only two eruptions of the Holocene that can be associated with the Tungnafellsjökull central volcano. Therefore, the understanding of Tungnafellsjökull‘s volcanic activity and behavior since the retreat of the glacier depends on research of those lava fields. Here, calculations of the volume and thickness of the Tunguhraun and Dvergagígahraun lavas are presented. Due to lack of data on the topography beneath these prehistoric lavas, an elevation model estimating the topography under the lavas was created, using elevation values around the lava fields and on the kipukas. For these elevation values, as well as those of the lava field, the ArcticDEM was used. Mapped outlines and the interpolated elevation models coupled with an elevation model of the current landscape provided the required data to calculate the approximate volumes of the two lava fields. The Tunguhraun lava is rather small and very thin with a volume of 0.15 km3 and an average thickness of 0.7 m. The Dvergagígahraun lava, on the other hand, is a bit thicker, but one of the smallest lava fields in Iceland, with a volume of 0.36 x 10-2 km3 and an average thickness of 3.1 m. The interpolation for the underlying topography is an estimation and might miss smaller depressions and elevations. As lava tends to flow into depressions, the calculated values might be underestimations. Since the topography in the area has a low relief, big differences are unlikely. Tunguhraun og Dvergagígahraun eru hraun á miðhálendi Íslands. Þau eru einu nútímahraunin sem tengd hafa verið megineldstöð Tungnafellsjökuls og eru rannsóknir á þeim því mikilvægar til að skilja virkni og hegðun eldstöðvakerfis Tungnafellsjökuls á nútíma. Í þessari rannsókn var rúmmál og þykkt Tunguhrauns og Dvergagígahrauns metið. Þar sem landslag undir hraununum er óþekkt var undirlag þeirra metið út frá landslagi í kringum þau og áætlað hæðarlíkan fyrir undirlag hraunsins búið til út frá ...