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Geological Hotspot
In geology, hotspots (or hot spots) are volcanic locales thought to be fed by underlying mantle that is anomalously hot compared with the surrounding mantle. Examples include the Hawaii, Iceland, and Yellowstone hotspots. A hotspot's position on the Earth's surface is independent of tectonic plate boundaries, and so hotspots may create a chain of volcanoes as the plates move above them. There are two hypotheses that attempt to explain their origins. One suggests that hotspots are due to mantle plumes that rise as thermal diapirs from the core–mantle boundary. The alternative plate theory is that the mantle source beneath a hotspot is not anomalously hot, rather the crust above is unusually weak or thin, so that lithospheric extension permits the passive rising of melt from shallow depths. Origin The origins of the concept of hotspots lie in the work of J. Tuzo Wilson, who postulated in 1963 that the formation of the Hawaiian Islands resulted from the slow movement of a tectoni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hawaii Hotspot Cross-sectional Diagram
Hawaii ( ; haw, Hawaii or ) is a U.S. state, state in the Western United States, Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only state geographically located within the tropics. Hawaii comprises Midway Atoll, nearly the entire Hawaiian Islands, Hawaiian archipelago, 137 High island, volcanic islands spanning that are physiography, physiographically and Ethnography, ethnologically part of the Polynesian subregion of Oceania. The state's ocean coastline is consequently the list of U.S. states and territories by coastline, fourth-longest in the U.S., at about . The eight main islands, from northwest to southeast, are Niihau, Niihau, Kauai, Kauai, Oahu, Oahu, Molokai, Molokai, Lanai, Lānai, Kahoolawe, Kahoolawe, Maui, and Hawaii (island), Hawaii—the last of these, after which the state is named, is often called the "Big Island" or "Hawa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
