Volcanic tremor and plume height hysteresis from Pavlof Volcano, Alaska

The March 2016 eruption of Pavlof Volcano, Alaska produced ash plumes that canceled over 100 flights in North America. The eruption produced strong tremor recorded by seismic and remote low-frequency acoustic (infrasound) stations, including the EarthScope Transportable Array. The relationship between the tremor amplitudes and plume height changes considerably between the waxing and waning portions of the eruption. Similar hysteresis has been observed between seismic river noise and discharge during storms, suggesting flow and erosional processes in both rivers and volcanoes can produce irreversible structural changes detectable in geophysical data. We propose that the time-varying relationship at Pavlof arose from changes in the tremor source related to volcanic vent erosion. This relationship may improve estimates of volcanic emissions and characterization of eruption size and intensity.