Explosions and periodic tremor at Karymsky volcano, Kamchatka, Russia
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 t...
Published in: | Geophysical Journal International |
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Main Authors: | , , |
Format: | Text |
Language: | English |
Published: |
Oxford University Press
2004
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Subjects: | |
Online Access: | http://gji.oxfordjournals.org/cgi/content/short/158/3/1151 https://doi.org/10.1111/j.1365-246X.2004.02239.x |
Summary: | 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. |
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