The Hawaiian Islands and the chain of seamounts that continue their trend for about 6, kilometers 3, miles into the northwest Pacific Ocean are an example of a hotspot track. The Island of Hawaii is the youngest, and most active, volcano in the chain. Active volcanism on Loihi Seamount, which is located off the southeast flank of the Island of Hawaii, however, may signal the future location for creation of a new island in the Hawaiian chain.
While the hotspot volcanism theory successfully explains the linear relationship between age and distance within some long-lived volcanic chains e. Such is the nature of science and why we continue to explore and learn. Home Ocean Exploration Facts What is a hotspot volcano? Mantle plumes create volcanoes, but as the hot spot is in continuous motion, a series of volcanoes are created, eventually becoming the Islands.
A single volcano formed each of the islands apart from Isabela the largest island which is actually formed from the joining of six different volcanoes. The newly forming islands in Galapagos are in the north west of the area. Because these volcanoes are formed underwater, the lava spreads out across the sea floor spreading out. This means the islands are formed with gentle sloping sides and a main vent. This type of volcano is called a shield volcano. In the last years there have been over 50 eruptions from volcanoes in the Galapagos Islands.
This shows that the volcanoes are still active and the islands themselves are still forming. The most recent significant eruption was on Fernandina island in Often on Fernandina and Isabela you can see columns of steam and gas coming out of the volcanoes. Most of the Galapagos Islands are formed from basalt which is a type of rock formed from basaltic lava.
Basaltic lava is much more fluid than other types of lava and is usually from oceanic crust. One suggests that they are due to hot mantle plumes that rise as thermal diapirs from the core—mantle boundary. Well known examples include Hawaii and Yellowstone. The origins of the concept of hotspots lie in the work of J. Tuzo Wilson, who postulated in that the Hawaiian Islands result from the slow movement of a tectonic plate across a hot region beneath the surface.
Figure 2. Schematic diagram showing the physical processes inside the Earth that lead to the generation of magma. Partial melting begins above the fusion point. Most hotspot volcanoes are basaltic e.
As a result, they are less explosive than subduction zone volcanoes, in which water is trapped under the overriding plate. Where hotspots occur in continental regions, basaltic magma rises through the continental crust, which melts to form rhyolites. These rhyolites can form violent eruptions. For example, the Yellowstone Caldera was formed by some of the most powerful volcanic explosions in geologic history.
However, when the rhyolite is completely erupted, it may be followed by eruptions of basaltic magma rising through the same lithospheric fissures cracks in the lithosphere. An example of this activity is theIlgachuz Range in British Columbia, which was created by an early complex series of trachyte and rhyolite eruptions, and late extrusion of a sequence of basaltic lava flows.
Hotspot volcanoes are considered to have a fundamentally different origin from island arc volcanoes.
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