FIG 1.

(A) The initial plume of the Puyehue-Cordón Caulle eruption on 4 June 2011. Note that the direction of transport is to the southeast, bringing massive amounts of ash and pumice to Lake Nahuel Huapi (not visible under the plume and cloud cover). (NASA image courtesy of Jeff Schmaltz, MODIS Rapid Response Team, NASA/Goddard Space Flight Center.) (B) Two weeks after the initial eruption (20 June 2011), islands of pumice (gray formations, four of which are highlighted with yellow arrows) are visible in Lake Nahuel Huapi. (NASA image courtesy of Jeff Schmaltz, MODIS Rapid Response Team, NASA/Goddard Space Flight Center.) (C) A raft of pumice washes ashore at the southeast end of Lake Nahuel Huapi, near Bariloche. (Photo courtesy of E. Balseiro.) (D) Map showing the two main study lakes in relation to the plume depicted in panel A. (Adapted from reference 10.)