A rift zone is a feature of some volcanoes, especially shield volcanoes, in which a set of linear cracks (or rifts) develops in a volcanic edifice, typically forming into two or three well-defined regions along the flanks of the vent.[1] Believed to be primarily caused by internal and gravitational stresses generated by magma emplacement within and across various regions of the volcano, rift zones allow the intrusion of magmatic dykes into the slopes of the volcano itself. The addition of these magmatic materials usually contributes to the further rifting of the slope, in addition to generating fissure eruptions from those dykes that reach the surface. It is the grouping of these fissures, and the dykes that feed them, that serves to delineate where and whether a rift zone is to be defined.[2] The accumulated lava of repeated eruptions from rift zones along with the endogenous growth created by magma intrusions causes these volcanoes to have an elongated shape.[3] Perhaps the best example of this is Mauna Loa, which in Hawaiian means "long mountain",[4] and which features two very well defined rift zones extending tens of kilometers outward from the central vent.
- ^ W., Hazlett, Richard (2010-05-17). Volcanoes : global perspectives. Wiley-Blackwell. ISBN 9781405162500. OCLC 892899076.
{{cite book}}: CS1 maint: multiple names: authors list (link) - ^ Walker, George P. L. (1999-12-01). "Volcanic rift zones and their intrusion swarms". Journal of Volcanology and Geothermal Research. 94 (1–4): 21–34. Bibcode:1999JVGR...94...21W. doi:10.1016/S0377-0273(99)00096-7.
- ^ Annen, C.; Lénat, J. -F.; Provost, A. (2001-03-01). "The long-term growth of volcanic edifices: numerical modelling of the role of dyke intrusion and lava-flow emplacement". Journal of Volcanology and Geothermal Research. 105 (4): 263–289. Bibcode:2001JVGR..105..263A. doi:10.1016/S0377-0273(00)00257-2.
- ^ ""Mauna Loa: Earth's Largest Volcano". USGS. 2 February 2006. Retrieved 21 October 2015".