Study of the Seismicity Associated to Four Cycles of Dome Growth and Destruction at Colima Volcano, Mexico

From 1990 to 2005, there occurred four cycles of dome growth and explosive dome destruction at Colima volcano. We describe these cycles, focusing on the seismic characteristics of the last three cycles from 1997 and 2005, for which we the best data is available. Four episodes of effusive dome growth took place: from early 1991 to late 1992, from November 1998 into January 1999, from November 2001 through February 2003, and from September 2004 into 2005. The rate of extrusion during these episodes, ranged from a low extrusion rate accompanied by seismicity and evolved with time to a high rate of aseismic extrusion for the last episode that in 2004. The first of these four extrusive episodes was followed by dome-destroying explosions in July 1994. The second extrusive episode, was followed by 4 dome-destroying explosions over six months and a fifth explosion seventeen months later, while the third extrusive episode, of 2002-2003, was followed by 3 dome-destroying explosions over two months. A fourth extrusive episode began in 2004. Each of all the explosions recorded was somewhat different, for each of them we compare the total seismic energy released during the hours prior to each explosion, during each explosion, and during the hours after each explosion. We also propose an additional method for classifying the explosions based on coupled acoustic waves and describe characteristics of the volcanic earthquakes recorded.