Search results
Results from the WOW.Com Content Network
The most active shield volcano in Africa is Nyamuragira. Eruptions at the shield volcano are generally centered within the large summit caldera or on the numerous fissures and cinder cones on the volcano's flanks. Lava flows from the most recent century extend down the flanks more than 30 km (19 mi) from the summit, reaching as far as Lake Kivu.
This list of shield volcanoes includes active, dormant and extinct shield volcanoes. Shield volcanoes are one of the three types [ specify ] of volcanoes. They have a short cone shape, and have basaltic lava which means the lava has low viscosity (viscosity is a measure of the ability for a liquid to flow)
Axial Seamount is a shield volcano, which means it's shaped like a shield rather than a steep-sided cone volcano. Its caldera at the top is a few miles wide and long, and about 300 feet deep.
Mount Siple (/ ˈ s aɪ p ə l / SIGH-p'l) [5] is a potentially active Antarctic shield volcano, rising to 3,162 metres (10,374 ft) and dominating the northwest part of Siple Island, which is separated from the Bakutis Coast, Marie Byrd Land, by the Getz Ice Shelf. [6] Its youthful appearance strongly suggests that it last erupted in the Holocene.
Mount Wrangell, (Ahtna: K’ełt’aeni, or K’ełedi when erupting) [3] is a massive shield volcano located in Wrangell-St. Elias National Park and Preserve in southeastern Alaska, United States. The shield rises over 12,000 feet (3,700 m) above the Copper River to its southwest.
Peralkaline rhyolites erupt at relatively high temperatures of more than 1,200 °C (2,190 °F). They comprise bimodal shield volcanoes at hotspots and rifts (e.g. Rainbow Range, Ilgachuz Range and Level Mountain in British Columbia, Canada). [15] Eruptions of rhyolite lava are relatively rare compared to eruptions of less felsic lavas.
The field contains at least 35 vents, arranged in a rough concentric pattern 50 kilometers (31 mi) across. The central part of the field is the most mafic, consisting of tholeiitic basalt shield volcanoes, with andesite vents further out and rhyodacite vents in the outer part of the field.
An early stage of the July 12, 2009, eruption of Sarychev volcano, seen from space. Viscous magmas cool beneath the surface before they erupt. As they do this, bubbles exsolve from the magma. Because the magma is viscous, the bubbles remain trapped in the magma. [2] As the magma nears the surface, the bubbles and thus the magma increase in volume.