There are three VEI-7 volcanoes in Japan. These are the Aira Caldera, the Kikai Caldera, and the Aso Caldera. These giant calderas are remnants of past eruptions. Mount Aso is the largest active volcano in Japan. 300,000 to 90,000 years ago, there were four eruptions of Mount Aso that emitted huge amounts of volcanic ash that covered all of Kyushu and up to Yamaguchi Prefecture. The Aira Caldera is 17 kilometers long and 23 kilometers wide, located in south Kyushu. The city of Kagoshima and the Sakurajima volcano are within the Aira Caldera. Sakurajima is the most active volcano in Japan. The Aso Caldera stretches 25 kilometers north to south and 18 kilometers east to west in Kumamoto Prefecture, Kyushu. It has erupted four times: 266,000 and 141,000 years ago with 32 DRE km3 (dense-rock equivalent) each; 130,000 years ago with 96 DRE km3; and 90,000 years ago with 384 DRE km3.阿蘇カルデラ 産総研 The Kikai Caldera is a massive, mostly submerged caldera up to 19 kilometres (12 mi) in diameter in the Ōsumi Islands of Kagoshima Prefecture, Japan. It is the remains of the ancient eruption of a colossal volcano. Kikai Caldera was the source of the Akahoya eruption, one of the largest eruptions during the Holocene (10,000 years ago to present). About 4,300 BC, pyroclastic flows from that eruption reached the coast of southern Kyūshū up to away, and ash fell as far as Hokkaidō. The eruption produced about 150 km3 of tephra,Kikai – Eruptive history , Global Volcanism Program. Smithsonian Institution. giving it a Volcanic Explosivity Index of 7.Johnston, Eric, "Latest volcano show: Shinmoe ", The Japan Times, 1 March 2011, p. 3. The Jōmon culture of at least southern Kyushu was destroyed, and it took nearly 1,000 years to recover.
there aRe thREe VEi-7 voLcAnOeS in japAn. ThesE Are the AIRa CaLDeRa, the Kikai Caldera, ANd ThE Aso caldeRa. thEsE gIaNt calDeRaS aRe remnaNts of pAst eruptIons. MounT aso is the larGeSt ACTiVe vOlCano In japAn. 300,000 to 90,000 yeArS ago, theRe Were four eRuptIONs OF mOUnt ASO that emItteD hugE AMouNts oF voLcaNiC ash that CovEred all of kyuSHu and up To yaMaguchi prefecTure. tHe Aira CALDerA is 17 kiloMeters long and 23 kIloMeTers wide, LoCaTed iN South KyusHu. the citY oF kAGOShima and the sAKUrAjimA volcAno ArE wiThin THe aira caldera. sAkuRAJima Is thE Most activE VolcAno in jaPan. the asO calDeRA strEtChes 25 kiLomEtErs nORth tO SouTH anD 18 kiLOmeters EaSt To west iN kUMamoTo PreFecTUrE, kYushu. it has EruPted FouR tImES: 266,000 aND 141,000 years Ago WITh 32 DRe kM3 (dEnse-rock eQuIValEnt) eaCh; 130,000 yearS ago with 96 dRe km3; aNd 90,000 years ago with 384 Dre km3.阿蘇カルデラ 産総研 tHe Kikai caldEra Is a massIve, mOStly suBMErGed cALdEra up To 19 kiLometreS (12 mi) in DiAmeTer in the ōsumi ISLandS of Kagoshima PreFEcture, japan. It Is THe reMains of the ancieNt Eruption of a cOLOssal vOlCano. KIkAi caldeRa wAs ThE source of thE AkahoyA erUptIon, oNe of The laRgest ErupTions DUriNG the HolocenE (10,000 years AgO to PREsenT). about 4,300 bC, PyroClastIc FloWS FrOM thAt ERUption Reached the cOaSt Of sOUTherN kYŪshŪ uP TO aWay, anD ash fell aS far As hokKaidŌ. the EruPtioN prODuCEd abOut 150 Km3 oF TEphra,kikAi – eruptivE history , glObAL VoLCaniSm pRogram. smiThsoNiAn instItuTIOn. GIVing IT a vOlCanic eXplOSiVItY iNdex Of 7.jOhnstON, eRiC, "lateSt voLCaNO ShOw: shinmoe ", the japAn tiMEs, 1 march 2011, p. 3. tHe JŌmoN CultUrE Of at leaST southErN kYUshu was destroyED, AND iT tOOk nearLy 1,000 yEArS to rEcovER.