The Australian mainland miss combat-ready volcanoes , but its geologic history look very different with the designation of a 2,000 - kilometer - long ( 1,240 - mile - recollective ) volcanic track , the longest known on any continent . The first vent on the track are 33 million class old , but the personnel responsible may still be induce an effect on the sea flooring off Tasmania .
Most of the domain ’s volcanoes lie where tectonic crustal plate meet , peculiarly around theRing of Fire , or atmid - ocean rooftree . However , exceptions such as volcanoes in Hawaii can be found within plates . The most pop , although still disputed , account is that these sit abovemantle plume , where hot cloth rise up from the boundary between the cape and core , forcing its way through the crust to be free at the aerofoil .
Image Credit : Hannes Grobe / AWI /Wikimedia Commons
Plumes are intend to be fixed relative to the Earth ’s core . As the tectonic plates move , new locations are exposed , with active volcano above the plumage and a data track of extinct peaks allow behind . TheHawaiian racetrack , including older mint now eroded beneath the sea , is far longer , butDr . Rhodri Daviesof the Australian National University saysYellowstone Snake River Plainwas thought to be the most extended example within a continental dental plate .
However , Davies reportsin Naturethat Australia host a track three times as long as Yellowstone . Dubbed " Cosgrove racecourse , " it begins with ancient volcanoes like Pinnacle Rock in north Queensland . These have been key out as the likely remnants of a pall plumage for decades .
However , other portion of the cart track areless obvious . Central New South Wales and Victoria boniface thin layers of the volcanic mineralleucitite . In between are stretch of up to 700 kilometers ( 435 naut mi ) without any sign of volcanic activity at all , leading geologist to reject an association between the volcanic provinces . However , Davies state the ages are unadulterated to be formed by the continent cash in one’s chips above a single plume .
Image : The path of the volcanic track across eastern Australia . Credit : Drew Whitehouse / NCI NationalFacilityVizLab.
Humphrey Davy attributes the surface differences to “ dramatic variations in the thickness of thelithosphere ” in the region . “ In north Queensland , the geosphere is only 80 km [ 50 miles ] slurred , ” he told IFLScience , allow magma to make its way to the control surface . However , evidence from the fastness at which quake propagate through the Australian gall point that for other contribution of the lead , the geosphere is more than130 kilometers ( 81 miles ) thick , preventing volcanic activeness . Intermediate thicknesses produce the potassium - rich leucitite .
thing get complicated in the south , as the plumage ’s patch crosses a chain of extinct volcanoes that Davy told IFLScience are triggered by quite a different phenomenon , known asedge - driven convection . where volcanic activeness is a result of a shrewd bound between thick and flimsy sections of the geosphere . “This is the first documented case of the interaction of a mantel feather and edge - driven convection , ” Davies enjoin .
“ The chain is so recollective because Australia is the fastest move continent , travel north at about 7 cm a class . ” Humphrey Davy told IFLScience . This motion has carry the Australian mainland beyond the plume , now located off the coast of Tasmania . “ There are no cognize volcanic volcanic eruption . Nothing obvious on the sea floor , but there have been earthquakes in the neighborhood and it postulate to be investigated further . ”
