Evidence for Recent Large Magnitude ExplosiveEruptions at Damavand Volcano, Iran withImplications for Volcanic Hazards

Damavand is a large dormant stratovolcano in the alborz mountains ofnorthern iran located in one of the most populous provinces, which could beadversely affected by tephra fall from damavand. the youngest known eruption isa lava flow on the western flanks with an age of7.3 ka. the volcanic products arepredominantly porphyritic trachyandesite. three major young pumice deposits,named here as mallar, karam poshteh and reyneh pumices, are identified, withprovisional ages in the interval >7.3 ka and < 25 ka. the deposits cover much ofthe southern and western flanks of the volcano. the mallar and reyneh depositsconsist of extensive basal pumice fall deposits with dispersal axes to the east,overlying pumiceous pyroclastic now deposits extending up to 20 km from thesummit and late-stage lahar deposits. the middle unit (karam poshteh) consists ofa coarse-grained pumice fall deposit with proximal welded facies dispersed to thewest, but lacks pyroclastic flow deposits. based on reconnaissance field data theywere formed by explosive eruptions ofvei4. some of the villages on the flanks ofthe volcano are built on pyroclastic now and lahar fans, and thus would be at highrisk in the event of future explosive eruptions. we present an analysis of winddata and the applications ofa computer tephra dispersal model to assess tephra fallhazards. explosive eruptions of damavand in the future would adversely affectlarge cities in the neighbouring provinces to the east, reflecting the dominantregional stratospheric wind directions.