Seismic Characteristics of the Vulcanian Explosions from the 2003–2005 Eruption at Colima Volcano, Mexico

Colima Volcano (19.512°N, 103.617°W, 4000 m.a.s.l.), located on the border between the states of Jalisco and Colima in western Mexico, is the most active volcano in the country. Its activity has taken place through diverse styles of eruption, from very explosive to effusive. In the last decades it has presented frequent vulcanian eruptions with episodes of dome construction–destruction. Four of these cycles occurred from 1990 to 2005, the last one from July 2003 to September 2005. We focus on this last period, for which we analyzed seismic phases and coupled pressure airwaves from high dynamic range seismograms, both in the time and frequency domains, to determine characteristic features, propagation velocities, and origin times for both deep seismic sources and the associated explosions. The results show that the sources of the P-waves associated with the explosions are not located at the summit, but instead at different shallow locations for the different explosions, suggesting the presence of various magmatic pathways within the volcano.