Plate Tectonics: intraplate (hot spot) volcanism / VolcanoDiscovery
The Great Rift Valley in eastern Africa, shown in the photograph above, is a good example of a continental rift valley. It is getting wider as the African Plate splits. Question: Explain the relationship between hotspots and volcanism. Plate Tectonics: Plate tectonics is the cause of some of the most interesting moments in our. According to the still prevailing theory, most if not all hotspots are believed to be the result of mantle plumes - bodies of warmer, and thus lighter, material within.
Describe the formation of hotspots and explain their relationship to plate movement. | MyTutor
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 the Ilgachuz 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.
The latter form over subduction zones, at converging plate boundaries.
When one oceanic plate meets another, the denser plate is forced downward into a deep ocean trench. This plate, as it is subducted, releases water into the base of the over-riding plate, and this water mixes with the rock, thus changing its composition causing some rock to melt and rise.
It is this that fuels a chain of volcanoes, such as the Aleutian Islandsnear Alaska. Hotspot volcanic chains[ edit ] Over millions of years, the Pacific Plate has moved over the Hawaii hotspotcreating a trail of underwater mountains that stretch across the Pacific Kilauea is the most active shield volcano in the world.
The volcano has erupted nonstop since and it is part of the Hawaiian—Emperor seamount chain.
Outline the formation of hotspots and explain their relationship to plate movement.
Mauna Loa is a large shield volcano. Its last eruption was in and it is part of the Hawaiian—Emperor seamount chain.
Bowie Seamount is a dormant submarine volcano and it is part of the Kodiak-Bowie Seamount chain. Axial Seamount is the youngest seamount of the Cobb—Eickelberg Seamount chain.
Intraplate (hot-spot) volcanism
Its last eruption was on 6 April It is dormant and it has cinder cones growing on the volcano. As the head impinges on the base of the lithosphere, it spreads outward into a mushroom shape.
This causes decompressional melting of the hot mantle material, i.
- How are hot spots related to plate tectonics?
- Explain the relationship between hotspots and volcanism.
- Plate tectonics affected by mantle hot spots
It is thought that the massive flood basalt provinces on earth are produced when large mantle plumes reach the lithosphere.
Note the bulbous plume heads, the narrow plume tails, and the flattened plume heads as they impinge on the outer sphere representing the base of the lithosphere.
Illustration how the progressively older islands formed above the stationary mantle plume Courtesy of the USGS. Mantle plumes appear to be largely unaffected by plate motions.
While a plume that feeds hot spot volcanoes remains stationary relative to the mantle, the plate above it usually moves. The result is that a chain of progressively older volcanoes are created on the overlying plate. The best examples of such "hot spot tracks" are found in the Pacific Ocean. The Pacific plate contains several linear belts of extinct submarine volcanoes, called seamounts.