Description
This 3D model has an aerial extent of about 200 x 90 m and captures a rather common, yet spectacular, occurrence in active rifts: a historical, basaltic, pahoehoe lava flow cascading into a 2.3-m-wide extension fracture within the Krafla Fissure Swarm, in northern Iceland. The fracture affects horizontal, 7 ka-old lava flows (Saemundsson et al., 2012). The surface of the cascading lava flow is marked by ogives, which are peculiar structures produced by the bending of the solidified crust during the movement of the underlying, still-molten lava; the convexity of the ogives points in the direction of the lava flow, towards the fracture and perpendicular to it (Pasquaré Mariotto et al., 2020). In the 3D model, two main extension fractures can be observed, associated with smaller ones, all parallel to each other; moreover, in the area is it possible to notice several, typically periglacial features, known as ‘pingo’, formed in response to the growth of ice lenses within the soil. The trend of the main fracture is about N10°, almost orthogonal to the overall spreading direction in the Nothern Volcanic Zone of Iceland, striking about N106° (Hjartardóttir et al., 2016).
Credits: UAV-based surveys and 3D DOM by Fabio L. Bonali; funding from MIUR project ACPR15T4_00098 (http://argo3d.unimib.it/). Model descripition by Fabio L. Bonali and Federico Pasquaré Mariotto.
References
- Pasquaré Mariotto F., Bonali, F. L., & Venturini, C. (2020). Iceland, an Open-Air Museum for Geoheritage and Earth Science Communication Purposes. Resources, 9(2), 14.
- Hjartardóttir, R., Einarsson, P., Magnusdóttir, S., Bjornsdóttir, Þ. and Brandsdóttir, B. (2016) Fracture systems of the Northern Volcanic Rift Zone, Iceland: an onshore part of the Mid-Atlantic plate boundary. In: Wright, T. J., Ayele, A., Ferguson, D. J., Kidane, T., Vye-Brown, C. (eds), Magmatic Rifting and Active Volcanism. Geological Society, London, Special Publications, 420, 297-314.