▁se ism ic ▁events ▁of ▁the ▁same ▁nature ▁recorded ▁in ▁the ▁recent ▁past ▁( 1 9 3 0 , ▁ 1 9 6 5 , ▁ 1 9 8 5 ). ▁ ▁In ▁ 2 0 0 7 , ▁the ▁U . S . ▁Ge ological ▁Survey ▁( US GS ), ▁in ▁co operation ▁with ▁Pan ama ' s ▁Science , ▁Technology ▁and ▁In nov ation ▁Secret ariat ▁( S EN AC Y T ) ▁and ▁the ▁U . S . ▁Agency ▁for ▁International ▁Development ▁( USA ID ), ▁published ▁a ▁study ▁on ▁different ▁aspects ▁of ▁Vol c án ▁Bar ú . ▁The ▁ 3 3 - page ▁report ▁out lined ▁potential ▁ha z ard ▁areas , ▁rock ▁composition , ▁and ▁areas ▁affected ▁by ▁previous ▁er u ptions ; ▁there ▁is ▁evidence ▁that ▁during ▁the ▁last ▁er u ption , ▁which ▁occurred ▁in ▁the ▁ 1 6 th ▁century , ▁the ▁de br is ▁a val anche ▁depos its ▁covered ▁a ▁volume ▁of ▁ 2 0 – 3 0   km ³ , ▁reaching ▁as ▁far ▁as ▁the ▁Pacific ▁Ocean ▁( the ▁largest ▁documented ▁in ▁Central ▁America ▁and ▁nearly ▁ 1 0 ▁times ▁the ▁area ▁covered ▁by ▁the ▁M t . ▁St . ▁Hel ens ▁de br is ▁a val anche ▁in ▁ 1 9 8 0 ). ▁ ▁Data ▁collected ▁at ▁several ▁locations ▁from ▁four ▁previous ▁er u ptions ▁which ▁occurred ▁during ▁the ▁last ▁ 1 6 0 0 ▁years ▁indicate ▁that ▁a ▁new ▁er u ption ▁would ▁last ▁several ▁years ,