Description
This model covers an area of about 1400 x 250 m, located along the the eastern part of the Hituholar (Pleistocene) volcano, belonging to the Krafla Fissure Swarm.
In the darker part of the model it is possible to recognize a major lava flow, erupted during the 1975-1984 Krafla Fires (Saemundsson et al., 2012). In the last stage of the eruption, the thickness of the lava decreased as a consequence of the emptying of the lava channel. The sides of the channel started to collapse toward the flow, due to unbuttressing. The consequence was the development of the series of open fissures that can be observed along both sides of the lava channel.
In the lighter part of the image, a hill made of hyaloclastites slopes toward the lava channel. The lower part of the slope is crossed by a series of narrow grabens that have been produced by the shallow emplacement of a dyke. At most grabens it is possible to recognize two normal faults dipping towards each other. Where the hills flatten out, the graben transitions to a set of fissures with a left-stepping geometry. Tibaldi et al. (2020) interpreted these faults and fractures as the result of a shallow dyke intrusion. In the flat area, between the fissure swarms, there is a broad field of pingo morphologies; pingos are elevated mounds (about 0.5 to 1 m in diameter) formed by the growth of ice lenses within the soil.
Credits: UAV-based survey and 3D DOM by Fabio L. Bonali, Luca Fallati and Elena Russo; model description by Alessandro Tibaldi and Federico Pasquaré Mariotto.
References
- Saemundsson, K., Hjartarson, A., Kaldal, I., Sigurgeirsson, M.A., Kristinsson, S.G. and Vikingsson, S. (2012) Geological map of the Northern Volcanic Zone, Iceland. Northern Part 1: 100.000. Reykjavik: Iceland GeoSurvey and Landsvirkjun.
- Tibaldi, A., Bonali, F. L., Russo, E., & Fallati, L. (2020). Surface deformation and strike-slip faulting controlled by dyking and host rock lithology: A compendium from the Krafla Rift, Iceland. Journal of Volcanology and Geothermal Research, 106835.