Specks of earthy greenish , brown and lily-white back breaker the sea just south of the mainland Japanese island of Kyushu , some of which have a rather recent volcanic chronicle . Compared to the gigantic volcanic scar that they sit on the flange of , though , such tiny small territories vanish into insignificance .
The region is home to a submarine , cauldron - similar edifice ( caldera ) named Kikai – and , according to a new paper inScientific Reportsspotted byThe New York Times , it ’s far from done and sprinkle .
This geological crucible has had a spectacularly crimson past stretching back 140,000 years , and its fit 7,300 age ago – the Akahoya irruption – unleashed more than 500 cubic kilometers ( 120 cubic miles ) of textile before leaving behind the 19 - klick ( 12 - mile ) caldera we can see today .
There ’s now an increasing amount ofevidencesuggesting that a lava bean exists within the caldera . This viscous pitcher’s mound , contain of thick rhyolitic lava and taking up around 32 cubic kilometers ( 7.7 cubic sea mile ) of space , was in all probability form after the Akahoya eruption , but it ’s far more than a mute oddment of a bygone era .
Judging by the fact that it ’s link up with an participating hydrothermal scheme , including high - temperature raging springs and evenhandedly profuse gas bubbling , this lava dome is “ still active ” , accord to the Kobe University - led team .
The researchers reached their conclusions after acquit three late surveys of the caldera aboard the shipFukae Maru . A cortege of experiment were carried out using a variety of techniques , from underwater robots to hokey quake to peek at Kikai ’s buried complex body part .
There ’s a lot about the attic that remains puzzling , and the timing and nature of its formation still require further investigation . In any case , the lava dome does n’t mean that a supereruption is imminent ; the two volcanic phenomena are rather different kettles of fish .
Previous oeuvre has suggested that there ’s a roughlyone - in-100 chanceof such an event pass in the next one C or so anywhere along the Japanese archipelago . There ’s actually no evidence to indicate that a supereruption is around the corner , at Kikai or anywhere else in the region . A lava dome is a curiosity , not a sign of impending doom .
The distributor point here is that this somewhat ungratified lava dome suggest that the magmatic generator beneath Kikai is n’t inhuman and dead , but fighting enough to have such an extrusion in the first post at some point in the late past times .
Fascinatingly , the domed stadium ’s geochemistry looks like unlike from the material give by the last supereruption at Kikai . In fact , the extrusion ’s chemical substance touch is similar to that of volcanic products institute on nearby islands , include Showa Iwo - jima , a deserted volcanic isle that burst forth from the wave in the mid-1930s .
This suggest that the magma source that formed Show Iwo - jima is the same one responsible for for render this lava dome , and both “ may pink a magma system that has evolved both chemically and physically since the 7,000 - twelvemonth - old supereruption . ”
The lava noodle is just one piece of the reciprocating saw puzzler of what the squad concern to as the “ whole caldera hertz ” . The motivation of paper like this is to improve our understanding of Kikai ’s past times in Holy Order to best see its futurity , especially if that future postulate a repeat of the Akahoya outcome .
University College London ’s ProfessorBill McGuire , a geophysicist and geologic hazards expert who was n’t regard in the sketch , told IFLScience that he fence the squad ’s use of the parole “ supereruption ” . This technically requires an ejection of at least twice as much volcanic material .
Still , the Akahoya event was “ huge , ” and “ something on this scale today would be … more than three times the size of the 1815 Tambora blast . The impact on the global climate would be significant , probably with a few degrees of cooling for several twelvemonth and major harvest nonstarter . ”
So where does this lava dome outfit in on this cycle , and what does it tell us about the next supereruption ? These are questions the team go for to answer when their next voyage take place this March .
