submarine volcano located juan ridge approximately west oregon standing high youngest volcano current center chain located center geological mid ocean ridge complex origins poorly understood set long low lying plateau large rift zones northeast southwest center volcano features unusual rectangular flanks sheet flows pit deep geology complicated intersection smaller surrounding detected 1970s satellite mapped explored 1980s large package sensors dropped established flanks received significant scientific attention following seismic detection submarine eruption volcano january time submarine eruption detected followed subsequent cruises analysis showed volcano generated lava flows thick total volume found erupted april producing mile wide lava flow fulfilling year cycle predicted geology setting youngest volcano current center chain chain terminates south alaska lies chain intersects approximately west oregon product sits ocean spreading center offset south ridge built triple junction north position entirely understood believed chain formed millions years inactive older mid ocean ridge years ago spreading center displacing building long juan ridge spreading centers recognized plate measurements near ridge separating rate year producing complex system oceanic basins ridges scientists questioned theory pointing high density chain overlapping incompatible origin form organized widely spaced chain exact nature remains unknown complex origins makes interesting features structure active volcanic site study magnetic modeled ridge history million years ago shown growth progressed north southward progression dating million years base long low lying plateau eastern defined series linear major volcanic extending approximately north south main summit smaller ill defined ones aligned roughly similar pattern basins volcano increase making unusually complex roughly size circular flattened shape summit marked unusual rectangular area slope breached southeast area offset rift zones defined sides boundary faults deep roughly deeper north south flows consist sheet flows lava ponds pit common arrangement walls suggests important component volcano early growth dome like structures heights small region largest nicknamed cone diameter relief features range deep northern rift zone long ridge running degrees northeast main rift multiple length far center reaching long deep area contains high amounts volcanic glass major eruption visible form elongated lava flow extending wall east main rift line found extensive low temperature northern half shorter newer southern rift zone consists rift surrounding subtle faults camera southern flank reveal area built sheet flows small lava ponds lava channels youngest flows aligned rift zones followed flows inside summit oldest appear originate directly completely covered accumulated sediment suggests growth pattern trend found known instance growth growth smaller largest brown bear connected narrow ridge running roughly perpendicular western wall little evidence interactions found hand southern rift zone creating zone intense northern edge smaller volcano interactions north complex forming unusual bent spreading center addition smaller structures directly east north south history early history juan ridge including detected 1970s satellite proximity western coast shallow depth easily accessible world unique geological setting active state makes interesting south scientific interest compiled surveyor trials survey specifically meant find link activity features areas increased temperature concentration indicative activity found unnamed discovered active black north pacific soon named central position intersection chain year founded program providing impetus studying volcano closely variety pressure sensors tilt sensors temperature dropped volcano came known detailed making best known features established study volcanic effect communities eruption eruption preceded large earthquake common volcanic activity movements volcano pressure deployed volcano recorded instances summit surface caused lava movement ranging granted access united_states navy system chain submerged originally navy detect russian submarines cold war maintained real time monitoring system organization event occurs able detect small earthquakes magnitude listening acoustic waves generated waves waves large distances minimal loss power making ideal way record submarine earthquakes course eruption earthquakes strong register land based systems interpret earthquake depth caused experienced single earthquake events november activity increased markedly recording culminating massive day event time eruption january began summit hours begun migrate south november moved south kilometers coincided lava release summit southern flank remained absolutely quiet suggesting completion cycle volcano earthquakes detected strong located earthquake activity concentrated summit southern rift zones majority events centered inside summit temperature pressure recorded average increase height respectively event close monitoring gives eruption distinction submarine eruption observed post eruption expedition organized conducted february conducted temperature depth optical casts unusual results dedicated survey showed changes volcano southern flank estimated flows july summit followed august september extensive observation collection program confirming estimates sheet flow long wide produced upper southern flank site active field southern flows area marked difference older sediments newer rock maximum ridge generated eruption crest southern flow high total volume roughly development eruption close monitoring provided fertile model submarine volcanic scientists scientific papers topic published soon eruption seismic activity virtually disappeared eruption monitoring volcano principally pressure deployed volcano flanks supplemented annual measurements pressure sensors mounted remotely operated vehicles applied local sensors shown slowly eruption swelling month number decreased years recovered approximately pre eruption swelling associates calculated eruption interval years predicting eruption occur approximately predictable way likely robust supply coupled thin crust location mid ocean ridge spreading center volcano surface continuously monitored entire eruption cycle prediction fulfilled july dive jason discovered new lava flows present year ago expeditionary crew recovered pressure found buried lava volcano showed eruption occurred april starting april instruments recorded hundreds seismic events handful noticed land based components system time volcano subsided produced wide lava flow event times larger eruption ecology canadian american collaborative expedition named visited northwestern edge summit investigate persistent temperature region series conducted scientists discovered vibrant vent community leading edge vent temperatures measured approximately surrounding environment camera 1980s 1990s revealed active state including known black northwest pacific centers recognized original site named southwestern field discovered late 1980s named ashes site located southeastern rift zone named castle primarily temperature composition changes time maintains roughly common identity individual communities generally lower surrounding fluid acidic result temperature feeding system uncertain vary vent fluid heavily enriched containing times element similar times regular tube worms family largest forming colonies thick places smaller feed smaller tube worms common groups family family common flora worm found sites descriptions juan ridge base ecosystem species include tube worm sea worm sea spider
Axial Seamount