03/02/2014-09/02/2014
This week’s volcano of the week is:
Chyulu Hills
Location: Kenya, East Africa
Type: Volcanic Field
Elevation: 2188m, 7177ft
Last Eruption: 1855
Status: Dormant
Details:
The volcanic field of Chyulu Hills are located 70 km northeast of Kilimanjaro and 150 km east of the Kenyan Rift; one of the most intensively studied rifts. The field extends to 100 km in a northwest-southeast direction and consists of cones, cinder cones and numerous lava flows.
Eruptions at Chyulu Hills began 1.4 million years ago when activity was concentrated in northern region of the volcano before moving to the southeast, leaving behind cinder cones. A mantle plume which is sourced from a larger plume under the rift is responsible for the eruptions at this volcano. According to seismic data, the crust is 44 km thick and molten magma is detected under the volcano.
The last eruption at Chyulu Hills was in 1855 at two of the cinder cones; Shaitani and Chainu. The activity is estimated to have been a VEI 2. According to radiocarbon dating volcanic activity also took place in 1470 (+/- 200 years) at Umani. The lava flows have varied in composition and consisted of foidites, basanites, alkali basalts, hawaiites to orthopyroxene-normative subalkali basalts.
Chyulu Hills also consist of one of the longest lava tubes in the world known as Leviathan cave.
Shentani lava flow surrounded by cones. The lava flow was formed in 1855 and measures 8 km long, 6 km wide and 5 metres thick. Source:
Source: Neville Sheldrick, http://www.dswtwildernessjournal.com/chyulu-hills-tsavos-water-tower/
Chyulu Hills: Source: Global Volcanism Programme
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