Hot Spot Volcanoes Animation Animation 2
Volcanic activity at mid-ocean ridge can form ocean islands (e. g Volcanic activity at mid-ocean ridge can form ocean islands (e.g., Iceland).
Volcanic Activity at Tectonic Plate Boundaries Source: USGS http://pubs.usgs.gov/gip/hawaii/page10.html
However Not all volcanoes occur at plate boundaries. HOT SPOTS: areas of volcanoes that result from plumes of hot solid material that have risen from deep within Earth’s mantle.
Map of hot spots http://www.math.montana.edu/~nmp/materials/ess/geosphere/advanced/activities/hotspots/index.html
Hawaiian Islands Source: USGS http://pubs.usgs.gov/gip/hawaii/page05.html
Northwest Movement of Pacific Plate Over Fixed Hawaiian Hot Spot Source: USGS http://pubs.usgs.gov/gip/hawaii/page12.html
Ages of Hawaiian Islands Source: http://volcano.und.edu/vwdocs/vwlessons/hotspots.html
Hot Spot Volcanism All of the mountains in this map of the floor of the Pacific Ocean are volcanoes Note that there are several long chains of volcanoes But there are also many individual volcanoes None of these volcanoes are formed along plate boundaries
Hot Spot Volcanism These isolated areas of volcanic activity are not associated with plate boundaries These volcanoes are found both on continents and out in the ocean
Hot Spot Volcanism A plume of hot mantle material rises up to the bottom of the lithosphere Melting occurs and magma is created These are called “hot spots” They can last for many millions of years
Hot Spot Volcanism The magma works its way to the surface over the hot spot and a volcano is formed Out in the ocean, the volcano may or may not reach the surface and form an island In fact, few oceanic volcanoes reach the surface
Hot Spot Volcanism As the moving plate carries the volcano away from the hot spot, the volcano dies out With time, another volcano may form This cycle may repeat many times, forming a long chain of under sea volcanoes and islands
Hot Spot Volcanism The Hawaiian Islands are the classic example of hot spot volcanism
Hot Spot Volcanism Every island in the Hawaiian Island chain was created by volcanic eruptions that occurred as the Pacific Oceanic Plate crossed over a hot spot
Hot Spot Volcanism In fact, the 7 main Hawaiian Islands are just the southern most portion of two great undersea mountain ranges, composed of hundreds of volcanoes, that runs for 6000 kilometers (4000 miles) across the floor of the Pacific Ocean
Hot Spot Volcanism The plate has moved to the northwest for more than 65 million years The big island of Hawaii is now over the hot spot
Hot Spot Volcanism The volcanoes that formed the Hawaiian islands are classified as shield volcanoes
Hot Spot Volcanism Shield volcanoes are characterized by broad, gentle slopes built up from repeated basaltic lava flows
Hot Spot Volcanism Not all eruption create big islands Molokini represents one eruption that is slowly being reclaimed by the sea
Hot Spot Volcanism Loihi Volcano, the youngest volcano of the Hawaiian Island Chain, lies about 20 km off the south coast of the Big Island Currently it rises 3500 meters above the surrounding sea floor and its summit is about 1000 meters beneath the surface
Fast and Slow Changes to Earth’s Surface http://www.pbs.org/wgbh/aso/tryit/tectonics/shockwave-nojs.html Changes due to Plate Tectonics Fast: Earthquakes and volcanoes Slow: Continental Drift
Fast Process: Volcanoes and Hot Spots http://www.youtube.com/watch?v=tfXGbzgGJ74 bill nye 8 min Silly bill: