Showing posts with label East Africa Volcanos. Show all posts
Showing posts with label East Africa Volcanos. Show all posts

Wednesday, November 2, 2016

The Ethiopian Volcano

Image result for erta ale volcano
Area: Lat. 13.6N, Long. 40.7E

Rise: 2,011 feet (613 m)

Erta Ale is an exceptionally remote and once in a while went to shield well of lava in the Afar locale of East Africa. It is Ethiopia's most dynamic spring of gushing lava and it has been in a condition of persistent emission since 1967. Daytime temperatures will probably be above 40 degrees Celcius and the base of the spring of gushing lava really lies underneath ocean level and it's summit ascends to 613 Meters. Erta Ale is known for it's 2 pit holes which have had dynamic magma lakes previously.


Erta Ale has experienced seven ejection occasions in the previous 125 years. Three of the early ejection dates, 1873, 1903, and 1904 are indeterminate. Be that as it may, 1906, 1940, 1960, and 1967 are settled occasions. Erta Ale has been emitting ceaselessly since 1967.

Two new studies on Erta Ale have as of late been distributed. Oppenheimer and Francis (1998) took a gander at the ramifications of seemingly perpetual magma lakes. They trust that Erta Ale's magma lake has been dynamic for in any event the most recent 90 years (making it one of the longest known memorable ejections). A lot of warmth are discharged by the spring of gushing lava however the measure of magma that ejects is moderately little. Oppenheimer and Francis conjectured that a higher magma thickness (brought about by the cooling of the magma in the lake) represses emissions. They suggested that the majority of the magma aggregates in the hidden hull as barriers and ledges. Since the Afar area is under augmentation, conditions are ideal for the infusion of dams and ledges.

Barrat and others (1998) took a gander at the science of the stones at Erta Ale. Rocks go in sythesis from basalt to rhyolite. Barrat and others found that two mantle sources were tapped for the basalts: one comparative in piece to the hotspot for mid-sea edge basalts (called MORB by geochemists) and one comparable in creation to the hotspot for sea island basalts (called OIB). Their information did not demonstrate a critical commitment of sialic material from the mainland covering. The silica-rich volcanics are gotten from fragmentary crystallization of basaltic magmas.

Tuesday, November 1, 2016

Erta Ale - the living Shield Volcano

Image result for erta ale volcano
Location: Lat. 13.6N, Long. 40.7E
Elevation: 2,011 feet (613 m)
Erta Ale is a very remote and rarely visited shield volcano in the Afar region of East Africa. It is Ethiopia's most active volcano and it has been in a state of continuous eruption since 1967. Daytime temperatures will likely be above 40 degrees Celcius and the base of the volcano actually lies below sea level and it's summit rises up to 613 Meters. Erta Ale is known for it's 2 pit craters which have had active lava lakes in the past. 
Erta Ale has undergone seven eruption events in the past 125 years. Three of the early eruption dates, 1873, 1903, and 1904 are uncertain. However, 1906, 1940, 1960, and 1967 are well established events. Erta Ale has been erupting continuously since 1967. 
Two new studies on Erta Ale have recently been published. Oppenheimer and Francis (1998) looked at the implications of long-lived lava lakes. They believe that Erta Ale's lava lake has been active for at least the last 90 years (making it one of the longest known historic eruptions). Large amounts of heat are released by the volcano but the amount of lava that erupts is relatively small. Oppenheimer and Francis speculated that a higher magma density (caused by the cooling of the lava in the lake) inhibits eruptions. They proposed that most of the magma accumulates in the underlying crust in the form of dikes and sills. Since the Afar region is under extension, conditions are favorable for the injection of dikes and sills. 
Barrat and others (1998) looked at the chemistry of the rocks at Erta Ale. Rocks range in composition from basalt to rhyolite. Barrat and others found that two mantle sources were tapped for the basalts: one similar in composition to the source for mid-ocean ridge basalts (called MORB by geochemists) and one similar in composition to the source for ocean-island basalts (called OIB). Their data did not show a significant contribution of sialic material from the continental crust. The silica-rich volcanics are derived from fractional crystallization of basaltic magmas.