01858nas a2200349   4500000000100000000000100001008004100002260001500043653001800058653001500076653002900091653003100120100001700151700001100168700001400179700001400193700001300207700001600220700001400236700001800250700001700268700001400285700001400299700001200313700001800325700001700343245017200360856005700532300001200589490000700601520090000608       2006                            d  cJuly, 200610adome collapse10aMontserrat10aSoufrière Hills Volcano10aSubmarine pyroclastic flow1 aJ. Trofimovs1 aL. Amy1 aG. Boudon1 aC. Deplus1 aE. Doyle1 aN. Fournier1 aM.B. Hart1 aJ. Komorowski1 aA. Le Friant1 aE.J. Lock1 aC. Pudsey1 aG. Ryan1 aR.S.J. Sparks1 aP.J. Talling00aSubmarine pyroclastic deposits formed at the Soufrière Hills volcano, Montserrat (1995\quotesinglbaseÄ\ \i2003): What happens when pyroclastic flows enter the ocean?  uhttp://geology.gsapubs.org/content/34/7/549.abstract  a549-5520 v343 aThe Soufrière Hills volcano, Montserrat, West Indies, has undergone a series of dome growth and collapse events since the eruption began in 1995. Over 90\% of the pyroclastic material produced has been deposited into the ocean. Sampling of these submarine deposits reveals that the pyroclastic flows mix rapidly and violently with the water as they enter the sea. The coarse components (pebbles to boulders) are deposited proximally from dense basal slurries to form steep-sided, near-linear ridges that intercalate to form a submarine fan. The finer ash-grade components are mixed into the overlying water column to form turbidity currents that flow over distances 30 km from the source. The total volume of pyroclastic material off the east coast of Montserrat exceeds 280 \texttimes 10<sup>6</sup> m<sup>3</sup>, with 65\% deposited in proximal lobes and 35\% deposited as distal turbidites.