scholarly journals Global volcanic earthquake swarm database and preliminary analysis of volcanic earthquake swarm duration

1996 ◽  
Vol 39 (2) ◽  
Author(s):  
J. P. Benoit ◽  
S. R. McNutt
Keyword(s):  
Preliminary Analysis ◽  
Geometric Mean ◽  
Earthquake Swarm ◽  
General Information ◽  
Earthquake Swarms ◽  
Volcanic Earthquake ◽  
Physical Processes ◽  
Reliable Parameter ◽  
Volcanic Earthquake Swarms ◽  
Global Data

Global data from 1979 to 1989 pertaining to volcanic earthquake swarms have been compiled into a custom-designed relational database. The database is composed of three sections: 1) a section containing general information on volcanoes, 2) a section containing earthquake swarm data (such as dates of swarm occurrence and durations), and 3) a section containing eruption information. The most abundant and reliable parameter, duration of volcanic earthquake swarms, was chosen for preliminary analysis. The distribution of all swarm durations was found to have a geometric mean of 5.5 days. Precursory swarms were then separated from those not associated with eruptions. The geometric mean precursory swarm duration was 8 days whereas the geometric mean duration of swarms not associated with eruptive activity was 3.5 days. Two groups of precursory swarms are apparent when duration is compared with the eruption repose time. Swarms with durations shorter than 4 months showed no clear relationship with the eruption repose time. However, the second group, lasting longer than 4 months, showed a significant positive correlation with the log10 of the eruption repose period. The two groups suggest that different suites of physical processes are involved in the generation of volcanic earthquake swarms.

Volcanic earthquake swarms at Mt. Erebus, Antarctica

1985 ◽  
Vol 114 (1-4) ◽  
pp. 357-369 ◽  
Author(s):  
Katsutada Kaminuma ◽  
Sadato Ueki ◽  
Kienle Juergen
Keyword(s):  
Earthquake Swarms ◽  
Volcanic Earthquake ◽  
Volcanic Earthquake Swarms

scholarly journals Tectonic stress regime in the 2003–2004 and 2012–2015 earthquake swarms in the Ubaye Valley, French Alps

2018 ◽  
Vol 175 (6) ◽  
pp. 1997-2008 ◽  
Author(s):  
Lucia Fojtíková ◽  
Václav Vavryčuk
Keyword(s):  
Seismic Activity ◽  
Joint Inversion ◽  
Earthquake Swarm ◽  
Active Faults ◽  
Tectonic Stress ◽  
Geological Mapping ◽  
Earthquake Swarms ◽  
Stress Regime ◽  
French Alps ◽  
Principal Axes

Abstract We study two earthquake swarms that occurred in the Ubaye Valley, French Alps within the past decade: the 2003–2004 earthquake swarm with the strongest shock of magnitude ML = 2.7, and the 2012–2015 earthquake swarm with the strongest shock of magnitude ML = 4.8. The 2003–2004 seismic activity clustered along a 9-km-long rupture zone at depth between 3 and 8 km. The 2012–2015 activity occurred a few kilometres to the northwest from the previous one. We applied the iterative joint inversion for stress and fault orientations developed by Vavryčuk (2014) to focal mechanisms of 74 events of the 2003–2004 swarm and of 13 strongest events of the 2012–2015 swarm. The retrieved stress regime is consistent for both seismic activities. The σ 3 principal axis is nearly horizontal with azimuth of ~ 103°. The σ 1 and σ 2 principal axes are inclined and their stress magnitudes are similar. The active faults are optimally oriented for shear faulting with respect to tectonic stress and differ from major fault systems known from geological mapping in the region. The estimated low value of friction coefficient at the faults 0.2–0.3 supports an idea of seismic activity triggered or strongly affected by presence of fluids.

An application of a stochastic model to a volcanic earthquake swarm

1975 ◽  
Vol 65 (2) ◽  
pp. 351-357
Author(s):  
John Filson ◽  
Tom Simkin
Keyword(s):  
Stochastic Model ◽  
Energy Release ◽  
Earthquake Swarm ◽  
Seismic Energy ◽  
Volcanic Earthquake ◽  
Model Studies ◽  
Seismic Energy Release ◽  
Earthquake Model ◽  
Event Occurrence

abstract The Kolomogorov model of event occurrence as developed by Knopoff in earthquake model studies has been applied to a volcanic earthquake swarm. It is shown that in this case, where the rate of seismic energy release was nearly constant in time, the model adequately relates the various seismicity statistics of the swarm.

Episodic earthquake swarms in the Mineral Mountains, Utah driven by the Roosevelt hydrothermal system

2021 ◽  
Author(s):  
Maria Mesimeri ◽  
Kristine Pankow ◽  
Ben Baker ◽  
J. Mark Hale
Keyword(s):  
Hydrothermal System ◽  
Hot Springs ◽  
Matched Filter ◽  
Earthquake Swarm ◽  
Earthquake Swarms ◽  
Earthquake Catalog ◽  
Spatial And Temporal Patterns ◽  
University Of Utah ◽  
South Central ◽  
The University

<p> The Mineral Mountains are located in south-central Utah within the transition zone from the Basin and Range to Colorado Plateau physiographic provinces, near the Roosevelt Hot Springs. First evidence of swarm-like activity in the area was found in 1981, when a six-station temporary network detected a very energetic swarm of ~1,000 earthquakes. More recently, in mid-2016, a dense local broadband seismic network was installed around the Frontier Observatory for Research in Geothermal Energy (FORGE) in southcentral Utah, ~10 km west of the Mineral Mountains. Beginning in 2016, the University of Utah Seismograph Stations detected, located, and characterized 75 earthquakes beneath the Mineral Mountains. In this study, we build an enhanced earthquake catalog to confirm the episodic swarm-like nature of seismicity in the Mineral Mountains. We use the 75 cataloged earthquakes as templates and detect 1,000 earthquakes by applying a matched-filter technique. The augmented catalog reveals that seismicity in the Mineral Mountains occurs as short-lived earthquake swarms followed by periods of quiescence. Earthquake relocation of ~800 earthquakes shows that activity is concentrated in a <2 km long E-W striking narrow zone, ~4 km east of the Roosevelt hydrothermal system. Two fault orientations, both N-S and E-W parallel to the Opal Mound and Mag Lee faults, respectively, are observed after computing composite focal mechanisms of highly similar earthquakes. After examining the spatial and temporal patterns of the best recorded earthquake swarm in October 2019, we find that a complex mechanism of fluid diffusion and aseismic slip is responsible for the swarm evolution with migration velocities reaching 10 km/day. We hypothesize that these episodic swarms in the Mineral Mountains are primarily driven by migrating fluids that originate within the Roosevelt hydrothermal system.</p>

scholarly journals Spatial distribution of crack structure in the focal area of a volcanic earthquake swarm at the Hakone volcano, Japan

2013 ◽  
Vol 65 (1) ◽  
pp. 51-55 ◽  
Author(s):  
Yu Nihara ◽  
Keiichi Tadokoro ◽  
Yohei Yukutake ◽  
Ryou Honda ◽  
Hiroshi Ito
Keyword(s):  
Spatial Distribution ◽  
Earthquake Swarm ◽  
Volcanic Earthquake ◽  
Hakone Volcano ◽  
Focal Area

Organic light emitting devices

2007 ◽  
Vol 15 (4) ◽  
Author(s):  
J. Godlewski ◽  
M. Obarowska
Keyword(s):  
General Information ◽  
Physical Processes ◽  
Organic Electroluminescence ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Organic Light Emitting Devices

AbstractThe purpose of this paper is to provide general information about basic physical processes involved in organic electroluminescence and to present the main parameters and advantages of organic light emitting devices (OLEDs).

scholarly journals The Volcanic Earthquake Swarm of October 20, 2009 in the Tatun Area of Northern Taiwan

2014 ◽  
Vol 25 (5) ◽  
pp. 625 ◽  
Author(s):  
Hsin-Chieh Pu ◽  
Cheng-Horng Lin ◽  
Yu-Chih Huang ◽  
Li-Chin Chang ◽  
Hsiao-Fen Lee ◽  
...  
Keyword(s):  
Earthquake Swarm ◽  
Volcanic Earthquake ◽  
Northern Taiwan

Statistical analysis of tidal effect on non-volcanic earthquake swarm activity in Wakayama Prefecture, southwest Japan

2021 ◽  
Author(s):  
Kazuki Machida ◽  
Hiroyuki Nagahama ◽  
Jun Muto
Keyword(s):  
Normal Stress ◽  
Earthquake Swarm ◽  
Tohoku Earthquake ◽  
Rate Variation ◽  
Volcanic Earthquake ◽  
Seismicity Rate ◽  
Tidal Forces ◽  
Tidal Triggering ◽  
Tidal Stress ◽  
Swarm Activity

<p>Earthquakes occur when the fault stress accumulates to the critical level. External forces such as tidal forces may contributes to the triggering of earthquakes reaching the critical state. For example, in the case of 2011 Tohoku Earthquake, it is reported that there is a correlation between tidal forces and the earthquakes prior to the mainshock. Earthquakes with smaller magnitude are also affected by tidal forces and expected to show correlation with tidal forces.</p><p>Tidal triggering of non-volcanic seismic swarm has not been well documented. So, we choose the Wakayama Prefecture as a targeting region. The cause of the earthquakes occurring in the region is considered to be the presence of the water below the seismogenic depth. The swarm activity continues from 1980s. We analyzed the shallow earthquakes in the northern part of Wakayama Prefecture from 1998 to 2016. We used statistical method called Schuster test to analyze correlation between earthquakes and tidal stress.</p><p>The result of the analysis shows that the earthquakes have a correlation with tidal forces which have the periodicity near the half of the lunar day and the amplitude of the seismicity-rate variation is about 16% of the average earthquake frequency. Correlation between the earthquakes and tidal forces is stronger at the periods when larger number of earthquakes occur. From tidal stress calculation, it is found that both solid tide and oceanic tide are important at this region. This study confirms that most of the earthquakes larger than M<sub>w</sub> 4 in the region occur in the rising period of tidal normal stress or just after the maximum of tidal normal stress. Therefore, tidal observation gives information about the criticality of rocks and temporal heterogeneity of the earthquake occurrence.</p>

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