Fracture systems of the Northern Volcanic Rift Zone, Iceland: an onshore part of the Mid-Atlantic plate boundary

• DOI: 10.1144/sp420.1
• Publication Date: 2015-01-29T02:28:17Z
• Authors: Á. R. Hjartardóttir; P. Einarsson; S. Magnúsdóttir; Þ. Björnsdóttir; B. Brandsdóttir
• Keywords: Fracture zone; Rift zone

Abstract Few divergent plate boundaries are subaerial. Active rifts in Iceland provide valuable surface information on spreading processes, rifting and faulting. The 200 km long 50 wide Northern Volcanic Rift Zone (NVZ) is composed of 7 volcanic systems, each consisting a central volcano with transecting fissure swarm. Fractures postglacial eruptive fissures the NVZ were analysed using aerial photographs satellite images to study their characteristics behaviour. While non-eruptive fractures characterize distal ( c. 40–100 km) parts swarms, most common at distances less than 20–30 from volcano. within swarms generally subparallel, N–NNE strike. Irregular orientations associated calderas volcanoes Askja Krafla, junction Tjörnes Fracture Zone, where high fracture densities also occur. WNW-orientated southern end Krafla Fissure Swarm, northern Kverkfjöll exhibit expressions transform zone. rift zone mostly seismically geodetically inactive, becoming highly active during events that occur time intervals tens few hundred years.