We examine seismic records of repeating explosions from Pavlof volcano, Alaska, during its 2007 eruption. Repetitive explosions are typical of Strombolian-style eruptions and allow measurement of relative time shifts between similar late-arriving phases using the technique called coda wave interferometry (Snieder et al., 2002). The measurements enable the detection of small changes in the volcanic interior of Pavlof. We are able to resolve an increase in the relative traveltime change of late-arriving seismic waves on the order of 0.3% over the course of two weeks. Based on the spectra of the explosions, their location inside the magma conduit, previous studies of Pavlof volcano, and 3D seismic modeling, we argue the most likely scenario is one in which the velocity and/or the geometry of the conduit changes. This demonstrates the sensitivity of coda wave interferometry to source effects, in addition to path effects, at volcanoes.
Haney, Matthew M.; van Wijk, Kasper; Preston, Leiph A.; and Aldridge, David F.. (2009). "Observation and Modeling of Source Effects in Coda Wave Interferometry at Pavlof Volcano". The Leading Edge, 28(5), 554. http://dx.doi.org/doi:10.1190/1.3124930