Archive for pyroclastic flows

Mount Láscar

Posted in Chile/Argentina with tags , , , , on May 2, 2011 by alfvforge

-photo from Smithsonian/Global Volcanism Program

Mount Láscar  is situated on the northern end of the Chilean Andes and is the most active stratovolcano there.  This means that Láscar is capable of emitting both pyroclastic and magmatic material.  Very frequently, too, do phreatic eruptions occur there in which hot water and even hotter volcanic rock come together and cause an explosive eruption of pulverized rock, but no magma.  Recent reports on Láscar’s eruption activity indicate that little more is occurring than explosive, central vent eruptions, which dwarf in comparison to Láscar’s most massive, historical eruption to date.  This is, of course, the 1993 eruption, which including phreatic eruptions, pyroclastic flows and an extrusion of the volcano’s dome structure; this eruption was also reported of having a VEI of 4.  The photo above shows smooth, light-colored deposits left over from the pyroclastic flow.  The column of erupted matter exceeded the volcano’s 5km altitude by an additional 12 km, emitting as much as 0.1 cubic kilometers of volcanic material.  Láscar is yet to experience an eruption quite as massive since then, but with magma flows and explosive rock bursting from its craters so often, who’s to say what’s cooking inside of her.