Investigation of hydrothermal boiling and steam quenching as possible sources of volcanic tremor and geothermal ground noise

AbstractA phreatic eruption suddenly occurred at Motoshirane (Kusatsu-Shirane volcano, Japan) at 10:02 JST on January 23, 2018. A member of the Japan Self-Defense Force was killed by volcanic blocks during training in Motoshirane, and 11 people were injured by volcanic blocks or fragments of broken glass. According to a field survey, ash fall was confirmed in Minakami, about 40 km east-northeast from Motoshirane. Although the eruption was not captured by a distant camera, the eruption plume/cloud was captured by three of the Japan Meteorological Agency’s operational weather radars. These radars observed the echo propagated to the northeast in the lower troposphere, and to the east in the middle troposphere. This is generally consistent with the observed ash fall distribution. Using the modified probabilistic estimation method, the maximum plume height was estimated to be about 5580 ± 506 m (1σ) above sea level. Estimates of the erupted mass based on the range of plume heights from radar observations and the duration of volcanic tremor during the eruption (about 8 min) do not match that obtained from a field survey (3.0–5.0 × 107 kg). This discrepancy confirms that estimates of erupted mass based on plume heights must account for eruption style parametrically, which can only be constrained by case studies of varied eruption styles.

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Statistical analysis of Stromboli VLP tremor in the band [0.1–0.5] Hz: some consequences for vibrating structures

Nonlinear Processes in Geophysics ◽

10.5194/npg-13-393-2006 ◽

2006 ◽

Vol 13 (4) ◽

pp. 393-400 ◽

Cited By ~ 11

Author(s):

E. De Lauro ◽

S. De Martino ◽

M. Falanga ◽

M. Palo

Keyword(s):

Frequency Band ◽

High Frequency ◽

Noise Source ◽

Volcanic Tremor ◽

Large Data ◽

Musical Instruments ◽

Data Set ◽

Long Period ◽

Vibrating Structures ◽

Analyze Time Series

Abstract. We analyze time series of Strombolian volcanic tremor, focusing our attention on the frequency band [0.1–0.5] Hz (very long period (VLP) tremor). Although this frequency band is largely affected by noise, we evidence two significant components by using Independent Component Analysis with the frequencies, respectively, of ~0.2 and ~0.4 Hz. We show that these components display wavefield features similar to those of the high frequency Strombolian signals (>0.5 Hz). In fact, they are radially polarised and located within the crater area. This characterization is lost when an enhancement of energy appears. In this case, the presence of microseismic noise becomes relevant. Investigating the entire large data set available, we determine how microseismic noise influences the signals. We ascribe the microseismic noise source to Scirocco wind. Moreover, our analysis allows one to evidence that the Strombolian conduit vibrates like the asymmetric cavity associated with musical instruments generating self-sustained tones.

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Source spectrum and source time function of volcanic tremor determined with a dense seismic network near the summit crater of Izu-Oshima Volcano, Japan

Journal of Geophysical Research Atmospheres ◽

10.1029/93jb03207 ◽

1994 ◽

Vol 99 (B5) ◽

pp. 9523-9532 ◽

Cited By ~ 8

Author(s):

Jun Oikawa ◽

Yoshiaki Ida ◽

Koshun Yamaoka

Keyword(s):

Volcanic Tremor ◽

Summit Crater ◽

Time Function ◽

Seismic Network ◽

Source Spectrum ◽

Source Time Function

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Time reversal imaging of synthetic volcanic tremor sources

Geophysical Research Letters ◽

10.1029/2009gl038178 ◽

2009 ◽

Vol 36 (12) ◽

Cited By ~ 20

Author(s):

Ivan Lokmer ◽

Gareth S. O'Brien ◽

Daniel Stich ◽

Christopher J. Bean

Keyword(s):

Time Reversal ◽

Volcanic Tremor

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An Efficient Equivalent Circuit Model for the EMC Analysis of Power/Ground Noise

2008 12th IEEE Workshop on Signal Propagation on Interconnects ◽

10.1109/spi.2008.4558350 ◽

2008 ◽

Author(s):

X. C. Wei ◽

E. P. Li ◽

E. X. Liu

Keyword(s):

Equivalent Circuit ◽

Equivalent Circuit Model ◽

Circuit Model ◽

Ground Noise

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Combining Distributed Acoustic Sensing and Beamforming in a Volcanic Environment on Mount Meager, British Columbia.

10.5194/egusphere-egu21-7927 ◽

2021 ◽

Author(s):

Sara Klaasen ◽

Patrick Paitz ◽

Jan Dettmer ◽

Andreas Fichtner

Keyword(s):

British Columbia ◽

Power Distribution ◽

High Frequency ◽

Low Frequency ◽

Volcanic Tremor ◽

Extreme Environment ◽

Volcanic Complex ◽

Acoustic Sensing ◽

Distributed Acoustic Sensing ◽

Volcanic Environment

We present one of the first applications of Distributed Acoustic Sensing (DAS) in a volcanic environment. The goals are twofold: First, we want to examine the feasibility of DAS in such a remote and extreme environment, and second, we search for active volcanic signals of Mount Meager in British Columbia (Canada).&#160;The Mount Meager massif is an active volcanic complex that is estimated to have the largest geothermal potential in Canada and caused its largest recorded landslide in 2010. We installed a 3-km long fibre-optic cable at 2000 m elevation that crosses the ridge of Mount Meager and traverses the uppermost part of a glacier, yielding continuous measurements from 19 September to 17 October 2019.We identify ~30 low-frequency (0.01-1 Hz) and 3000 high-frequency (5-45 Hz) events. The low-frequency events are not correlated with microseismic ocean or atmospheric noise sources and volcanic tremor remains a plausible origin. The frequency-power distribution of the high-frequency events indicates a natural origin, and beamforming on these events reveals distinct event clusters, predominantly in the direction of the main peaks of the volcanic complex. Numerical examples show that we can apply conventional beamforming to the data, and that the results are improved by taking the signal-to-noise ratio of individual channels into account.The increased data quantity of DAS can outweigh the limitations due to the lower quality of individual channels in these hazardous and remote environments. We conclude that DAS is a promising tool in this setting that warrants further development.

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Investigation of the pre-eruptive processes of the 2014/15 Holuhraun eruption based on extracted volcanic tremor signals

10.5194/egusphere-egu21-12812 ◽

2021 ◽

Author(s):

Zahra Zali ◽

Eva Eibl ◽

Matthias Ohrnberger ◽

Frank Scherbaum

Keyword(s):

Amplitude Ratio ◽

Ground Deformation ◽

Volcanic Tremor ◽

Simultaneous Occurrence ◽

Generation Process ◽

Glacier Surface ◽

Aerial Photos ◽

Seismic Amplitude ◽

Subglacial Eruptions ◽

Eruption Precursors

During volcanic unrest, multiple subsurface processes can happen simultaneously and may lead to an eruption. The analysis of seismic records in an unrest period before an eruption reveals information about the pre-eruptive processes and might be able to provide hints for a possible future eruption.The 2014&#8211;2015 Holuhraun eruption was the largest one in Iceland in 230 years. It was extensively monitored and studied in a variety of multidisciplinary research approaches. Intense seismicity and ground deformation were interpreted as magma propagation from B&#225;r&#240;arbunga volcano 48 km laterally at &#8764;6 km depth over two weeks before an eruption started at Holuhraun. Different processes including vertical and lateral magma migration, dike propagation, caldera subsidence, and subglacial eruptions happened in this period and some models linking these processes are suggested. In the two-week interval preceding the eruption, there is still no clear connection between the observed tremor and pre-eruptive processes. Both the tremor source location and tremor generation process are not well understood yet. While cauldrons as a sign of subglacial eruptions were identified on the glacier surface from aerial photos, these cauldrons might have been formed earlier and there is hence an uncertainty of a few days. A tremor location might help to constrain these dates. However, the simultaneous occurrence of intense seismicity and tremor hinders the study and location of tremor. Here, we use a recent volcanic tremor extraction algorithm (Zali et al., 2020) and extract pre-eruptive tremor signals in order to better locate them using the Seismic Amplitude Ratio Analysis (SARA) method. Furthermore, the occurrence of the tremor could open new insights into ascending magma and fluid migration as well as the timing and duration of the subglacial eruptions.We also observed short-lived tremors before the eruptions on August 29 and 31, which could be considered as eruption precursors. The primary investigation on the extracted tremor signals is promising while further analysis is on-going.

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