Abstract
Telica Volcano, Nicaragua, is a persistently restless volcano with daily seismicity rates that can vary by orders of magnitude without apparent connection to eruptive activity. Low-frequency (LF) events are dominant and peaks in seismicity rate show little correlation with eruptive episodes, presenting a challenge for seismic monitoring and eruption forecasting. A short period seismic station (TELN) has been operated on Telica's summit since 1993, and in 2010 the installation of a six-station broadband seismic and eleven-station continuous GPS network (the TESAND network) was completed to document in detail the seismic characteristics of a persistently restless volcano. Between our study period of November 2009 and May 2013, over 400,000 events were detected at the TESAND summit station (TBTN), with daily event rates ranging from 5 to 1400. We present spectral analyses and classifications of ~. 200,000 events recorded by the TESAND network between April 2010 and March 2013, and earthquake locations for a sub-set of events between July 2010 and February 2012. In 2011 Telica erupted in a series of phreatic vulcanian explosions. Six months before the 2011 eruption, we observe a sudden decrease in LF events concurrent with a swarm of high-frequency (HF) events, followed by a decline in overall event rates, which reached a minimum at the eruption onset. We observe repeated periods of high and low seismicity rates and suggest these changes in seismicity represent repeated transitions between open-system and closed-system degassing. We suggest that these short- and long-term transitions between open to closed-system degassing form part of a long-term pattern of stable vs. unstable phases at Telica. Stable phases are characterised by steady high-rate seismicity and represent stable open-system degassing, whereas unstable phases are characterised by highly variable seismicity rates and represent repeated transitions from open to closed-system degassing, where the system is unable to sustain steady open-system degassing. These observations have implications for seismic monitoring at persistently restless volcanoes as the recognition of unstable seismic phases may indicate the open-system degassing process cannot be sustained and explosions are likely.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 63-74 |
| Number of pages | 12 |
| Journal | Journal of Volcanology and Geothermal Research |
| Volume | 290 |
| DOIs | |
| State | Published - Jan 1 2015 |
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All Science Journal Classification (ASJC) codes
- Geophysics
- Geochemistry and Petrology
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Stable and unstable phases of elevated seismic activity at the persistently restless Telica Volcano, Nicaragua. / Rodgers, Mel; Roman, Diana C.; Geirsson, Halldor; Lafemina, Peter Christopher; McNutt, Stephen R.; Muñoz, Angelica; Tenorio, Virginia.
In: Journal of Volcanology and Geothermal Research, Vol. 290, 01.01.2015, p. 63-74.Research output: Contribution to journal › Article
TY - JOUR
T1 - Stable and unstable phases of elevated seismic activity at the persistently restless Telica Volcano, Nicaragua
AU - Rodgers, Mel
AU - Roman, Diana C.
AU - Geirsson, Halldor
AU - Lafemina, Peter Christopher
AU - McNutt, Stephen R.
AU - Muñoz, Angelica
AU - Tenorio, Virginia
PY - 2015/1/1
Y1 - 2015/1/1
N2 - Telica Volcano, Nicaragua, is a persistently restless volcano with daily seismicity rates that can vary by orders of magnitude without apparent connection to eruptive activity. Low-frequency (LF) events are dominant and peaks in seismicity rate show little correlation with eruptive episodes, presenting a challenge for seismic monitoring and eruption forecasting. A short period seismic station (TELN) has been operated on Telica's summit since 1993, and in 2010 the installation of a six-station broadband seismic and eleven-station continuous GPS network (the TESAND network) was completed to document in detail the seismic characteristics of a persistently restless volcano. Between our study period of November 2009 and May 2013, over 400,000 events were detected at the TESAND summit station (TBTN), with daily event rates ranging from 5 to 1400. We present spectral analyses and classifications of ~. 200,000 events recorded by the TESAND network between April 2010 and March 2013, and earthquake locations for a sub-set of events between July 2010 and February 2012. In 2011 Telica erupted in a series of phreatic vulcanian explosions. Six months before the 2011 eruption, we observe a sudden decrease in LF events concurrent with a swarm of high-frequency (HF) events, followed by a decline in overall event rates, which reached a minimum at the eruption onset. We observe repeated periods of high and low seismicity rates and suggest these changes in seismicity represent repeated transitions between open-system and closed-system degassing. We suggest that these short- and long-term transitions between open to closed-system degassing form part of a long-term pattern of stable vs. unstable phases at Telica. Stable phases are characterised by steady high-rate seismicity and represent stable open-system degassing, whereas unstable phases are characterised by highly variable seismicity rates and represent repeated transitions from open to closed-system degassing, where the system is unable to sustain steady open-system degassing. These observations have implications for seismic monitoring at persistently restless volcanoes as the recognition of unstable seismic phases may indicate the open-system degassing process cannot be sustained and explosions are likely.
AB - Telica Volcano, Nicaragua, is a persistently restless volcano with daily seismicity rates that can vary by orders of magnitude without apparent connection to eruptive activity. Low-frequency (LF) events are dominant and peaks in seismicity rate show little correlation with eruptive episodes, presenting a challenge for seismic monitoring and eruption forecasting. A short period seismic station (TELN) has been operated on Telica's summit since 1993, and in 2010 the installation of a six-station broadband seismic and eleven-station continuous GPS network (the TESAND network) was completed to document in detail the seismic characteristics of a persistently restless volcano. Between our study period of November 2009 and May 2013, over 400,000 events were detected at the TESAND summit station (TBTN), with daily event rates ranging from 5 to 1400. We present spectral analyses and classifications of ~. 200,000 events recorded by the TESAND network between April 2010 and March 2013, and earthquake locations for a sub-set of events between July 2010 and February 2012. In 2011 Telica erupted in a series of phreatic vulcanian explosions. Six months before the 2011 eruption, we observe a sudden decrease in LF events concurrent with a swarm of high-frequency (HF) events, followed by a decline in overall event rates, which reached a minimum at the eruption onset. We observe repeated periods of high and low seismicity rates and suggest these changes in seismicity represent repeated transitions between open-system and closed-system degassing. We suggest that these short- and long-term transitions between open to closed-system degassing form part of a long-term pattern of stable vs. unstable phases at Telica. Stable phases are characterised by steady high-rate seismicity and represent stable open-system degassing, whereas unstable phases are characterised by highly variable seismicity rates and represent repeated transitions from open to closed-system degassing, where the system is unable to sustain steady open-system degassing. These observations have implications for seismic monitoring at persistently restless volcanoes as the recognition of unstable seismic phases may indicate the open-system degassing process cannot be sustained and explosions are likely.
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U2 - 10.1016/j.jvolgeores.2014.11.012
DO - 10.1016/j.jvolgeores.2014.11.012
M3 - Article
AN - SCOPUS:84920136863
VL - 290
SP - 63
EP - 74
JO - Journal of Volcanology and Geothermal Research
JF - Journal of Volcanology and Geothermal Research
SN - 0377-0273
ER -