-800 active volcanoes that have been identified, most are located along the margins of the ocean basins-most notably within the circum-pacific belt known as the Ring of Fire.
-This group of volcanos consists mainly of composite cones that emite volatile- rich magma having an intermediate composition that occasionally produce awe-inspiring eruption.
-The volcanos conprising a second group emit very fluid basaltic lavas and are confined to the deep ocean basins including well know examples on Hawaii and Iceland.
-A thrid group includes those volanic structures that are irregularly distributed in the interior of the continents.
-Africa is notable because it has many potentially active volcanoes including Mount Kilimanjaro the highest point on the continent.
-until the late 1960s geologist had no explanation for the appaently haphaxard distribution of continental volcanoesnor were they able to account for the almost continuous chain of volcanoes that circles the margin of the pacific basin.
-Three zones of igneous activity and their relationship to plate boundaries.(1) along each convergent plate boundaries where plates move toward each other and one sinks beneath the other.(2) along divergent plate boundaries, where plates move away from each other and a new seafloor is created.(3) areas within the plates proper that are not associated with any plate boundary.
-Develop within the ocean and grow large enought for their tops to rise above the surface are labled island archipelagos in atlases. But geologist prerfer the more descriptive term Volcanic Islnd or simply island arcs.
-The early stage of lisland arc volcanism is typically dominated by the eruption of fluid basalts that build numerous sheildlike Structures on the ocean floor.
-Volcanism associated with convergent plate boundaries may also devlop where slabs of oceanic lithosphere are subducted under continental lithosphere to produce a continental volcanic arc.
-Intraplate volcnaism "within the plate" Canary Island, yellowstone, and several volcanic centers.
-Hot Spot: Localized volcanic region a few hundred kliometers across.
-About 10 percent of earth population lives in the vicinity of active volcano.
- Citys like: Seattle, Maxico city,Tokyo,Naples, and Ouite are located near a volcano.
-This group of volcanos consists mainly of composite cones that emite volatile- rich magma having an intermediate composition that occasionally produce awe-inspiring eruption.
-The volcanos conprising a second group emit very fluid basaltic lavas and are confined to the deep ocean basins including well know examples on Hawaii and Iceland.
-A thrid group includes those volanic structures that are irregularly distributed in the interior of the continents.
-Africa is notable because it has many potentially active volcanoes including Mount Kilimanjaro the highest point on the continent.
-until the late 1960s geologist had no explanation for the appaently haphaxard distribution of continental volcanoesnor were they able to account for the almost continuous chain of volcanoes that circles the margin of the pacific basin.
-Three zones of igneous activity and their relationship to plate boundaries.(1) along each convergent plate boundaries where plates move toward each other and one sinks beneath the other.(2) along divergent plate boundaries, where plates move away from each other and a new seafloor is created.(3) areas within the plates proper that are not associated with any plate boundary.
-Develop within the ocean and grow large enought for their tops to rise above the surface are labled island archipelagos in atlases. But geologist prerfer the more descriptive term Volcanic Islnd or simply island arcs.
-The early stage of lisland arc volcanism is typically dominated by the eruption of fluid basalts that build numerous sheildlike Structures on the ocean floor.
-Volcanism associated with convergent plate boundaries may also devlop where slabs of oceanic lithosphere are subducted under continental lithosphere to produce a continental volcanic arc.
-Intraplate volcnaism "within the plate" Canary Island, yellowstone, and several volcanic centers.
-Hot Spot: Localized volcanic region a few hundred kliometers across.
-About 10 percent of earth population lives in the vicinity of active volcano.
- Citys like: Seattle, Maxico city,Tokyo,Naples, and Ouite are located near a volcano.