A volcano is a rupture on the crust

A volcano is a rupture on the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.

Earth's volcanoes occur because its crust is broken into 17 major, rigid tectonic plates that float on a hotter, softer layer in its mantle.[1] Therefore, on Earth, volcanoes are generally found where tectonic plates are diverging or converging. For example, a mid-oceanic ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates pulling apart; the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates coming together. Volcanoes can also form where there is stretching and thinning of the crust's interior plates, e.g., in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande Rift in North America. This type of volcanism falls under the umbrella of "plate hypothesis" volcanism.[2] Volcanism away from plate boundaries has also been explained as mantle plumes. These so-called "hotspots", for example Hawaii, are postulated to arise from upwelling diapirs with magma from the core–mantle boundary, 3,000 km deep in the Earth. Volcanoes are usually not created where two tectonic plates slide past one another.

Erupting volcanoes can pose many hazards, not only in the immediate vicinity of the eruption. One such hazard is that volcanic ash can be a threat to aircraft, in particular those with jet engines where ash particles can be melted by the high operating temperature; the melted particles then adhere to the turbine blades and alter their shape, disrupting the operation of the turbine. Large eruptions can affect temperature as ash and droplets of sulfuric acid obscure the sun and cool the Earth's lower atmosphere (or troposphere); however, they also absorb heat radiated up from the Earth, thereby warming the upper atmosphere (or stratosphere). Historically, so-called volcanic winters have caused catastrophic famines.

ผลลัพธ์ (แอฟริกา) 1:

'N vulkaan is 'n breuk op die kors van 'n planetêre-massa voorwerp, soos die aarde, wat toelaat dat warm Lava, Vulkaanas, en gasse om te ontsnap uit 'n magma kamer onder die oppervlak. Aarde se vulkane voorkom, omdat die kors ingebreek 17 groot. , styf tektoniese plate wat dryf op 'n warmer, sagter laag in sy mantel. [1] Daarom, op aarde, vulkane is oor die algemeen gevind waar tektoniese plate uiteenlopende of konvergerende. Byvoorbeeld, 'n mid-oseaanrif, soos die Middel-Atlantiese Rif, het vulkane veroorsaak deur uiteenlopende tektoniese plate trek uitmekaar; die Stille Oseaan Ring van Vuur het vulkane veroorsaak deur konvergente tektoniese plate bymekaar kom. Vulkane kan ook vorm waar daar strek en uitdunning van die kors se binneland plate, bv, in die Oos-Afrikaanse Rift en die Wells Gray-Clearwater vulkaniese gebied en Rio Grande skeuring in Noord-Amerika. Hierdie tipe van vulkanisme val onder die sambreel van "plaat hipotese" vulkanisme. [2] Vulkanisme weg van plaatgrense is ook verduidelik as mantelpluime. Hierdie sogenaamde "hotspots", byvoorbeeld Hawaii, is gepostuleer ontstaan ​​as gevolg van opwelling diapirs met magma uit die kern-mantel grens, 3000 km diep in die aarde. Vulkane is gewoonlik tektoniese plate flippen afgelope Nie geskep waar twee mekaar. uitbars Vulkane Kan baie gevare, nie net in die onmiddellike omgewing van die uitbarsting inhou. Een so 'n gevaar is dat vulkaniese as 'n bedreiging vir die vliegtuig wees, in die besonder dié met jet enjins waar as deeltjies kan deur die hoë werkstemperatuur gesmelt word; die gesmelte deeltjies dan voldoen aan die turbine lemme en hul vorm verander, die orde van die werking van die turbine. Groot uitbarstings kan beïnvloed temperatuur as en druppels van swaelsuur verduister die son en koel die aarde se laer atmosfeer (of troposfeer); Maar hulle het ook absorbeer hitte uitgestraal van die aarde, en daardeur die boonste atmosfeer (of stratosfeer) warm gemaak. Histories het die sogenaamde vulkaniese winters veroorsaak katastrofiese hongersnood.