Explosions and periodic tremor at Karymsky volcano, Kamchatka, Russia: Explosions and periodic tremor at Karymsky volcano

• Main Authors: Lees, Jonathan M., Gordeev, Evgenii I., Ripepe, Maurizio
• Other Authors: University of North Carolina at Chapel Hill
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2004
• Subjects: eruption dynamics; harmonic tremor; Kamchatka; volcanic explosion
• Online Access: https://doi.org/10.17615/m2q8-1w45; https://cdr.lib.unc.edu/downloads/z029pd833?file=thumbnail; https://cdr.lib.unc.edu/downloads/z029pd833

The explosions of Karymsky volcano often produce signals containing a sequence of repeating pulses recorded on acoustic and seismic sensors, known as chugging. The amplitudes of these pulses correlate with the time interval between pulses. For a given measured acoustic pressure, seismic amplitudes take on arbitrary values up to a specific, empirically determined threshold. Conversely, events with a small seismic amplitude yielded acoustic waves with large variations and large-amplitude seismic events corresponded to large acoustic waves. These observations are not consistent with a source modelled by a resonating conduit. Rather, a model consisting of a sequence of discrete pulses explains the data and provides a framework for understanding the dynamics of degassing at the vent. The physical model for chugging involves a time-varying narrowing vent where gasses are released in a series of oscillations which appear to be harmonic but instead are modelled as short-term transients, or discrete pulses, suggestive of choked flow.