scholarly journals Methods for Eruption Prediction and Hazard Evaluation at Indonesian Volcanoes

2012 ◽  
Vol 7 (1) ◽  
pp. 26-36 ◽  
Author(s):  
Masato Iguchi ◽  
◽  
Surono ◽  
Takeshi Nishimura ◽  
Muhamad Hendrasto ◽  
...  
Keyword(s):  
Volcanic Activity ◽  
Hazard Evaluation ◽  
Seismic Amplitude ◽  
Geological Surveys ◽  
Cumulative Volume ◽  
Background Data ◽  
Tectonic Earthquakes ◽  
Gps Observation ◽  
Continuous Gps ◽  
Eruptive Rate

We report methods, based on geophysical observations and geological surveys, for the prediction of eruptions and the evaluation of the activity of 4 volcanoes in Indonesia. These are Semeru, Guntur, Kelud and Sinabung volcanoes. Minor increases in tilt were detected by borehole tiltmeters prior to eruptions at the Semeru volcano depending on the seismic amplitude of explosion earthquakes. The results show the possibility of prediction of the type and magnitude of eruption and the effectiveness of observation with a high signalto-noise ratio. The establishment of background data is important for evaluating volcanic activity in longterm prediction. Typical distributions of volcanic and local tectonic earthquakes were obtained around the Guntur volcano, where geodetic monitoring by continuous GPS observation is valuable. The cumulative volume of eruptive products is valuable for evaluating the potential for future eruption. The eruptive rate of the Kelud volcano is ca 2×106m3/y (dense rock equivalent), but the volume of the 2007 eruption was only 2×107m3, suggesting a still high potential for eruption. Based on geological surveys and dating, an eruption scenario is proposed for the activity of Mt. Sinabung, where phreatic eruptions occurred in 2010 after a historically long dormancy.

Observation of gliding tremors from the Gulf of Guinea might help solve over 50 year old mystery

2021 ◽  
Author(s):  
Charlotte Bruland ◽  
Sarah Mader ◽  
Céline Hadziioannou
Keyword(s):  
Spectral Analysis ◽  
Volcanic Activity ◽  
Rayleigh Waves ◽  
Spectral Characteristics ◽  
Gulf Of Guinea ◽  
Seismic Amplitude ◽  
Long Period ◽  
Amplitude Spectra ◽  
Using Data ◽  
Over Time

<p>In the 1960's a peak in the seismic amplitude spectra around 26 s was discovered and detected on stations worldwide. The source was located in the Gulf of Guinea, with approximate coordinates (0,0), and was believed to be generated continuously. A source with similar spectral characteristics was discovered near the Vanuatu Islands, at nearly the antipodal location of the Gulf of Guinea source. Since it was located close to the volcanoes in Vanuatu, this source is commonly attributed to magmatic processes. The physical cause of the 26 s microseism, however, remains unclear.</p><p>We investigate the source location and evolution of the 26 s microseim using data from permanent broadband stations in Germany, France and Algeria and temporary arrays in Morocco, Cameroon and Botswana for spectral analysis and 3-C beamforming to get closer to resolving the source mechanism responsible for this enigmatic signal. We find that the signal modulates over time and is not always detectable, but occasionally it becomes so energetic it can be observed on stations worldwide. Such a burst can last for hours or days. The signal is visible on stations globally approximately 30 percent of the time. Our beamforming analysis confirms that the source is located in the Gulf of Guinea, as shown in previous studies, and that the location is temporally stable. Whenever the signal is detectable, both Love and Rayleigh waves are generated. We discover a spectral glide effect associated with the bursts, that so far has not been reported in the literature. </p><p>The spectral glides last for about two days and are observed on stations globally. Although at higher frequencies, very long period tremors and gliding tremors are also observed on volcanoes as Redoubt in Alaska and Arenal in Costa Rica, suggesting that the origin of the 26 s tremor is also volcanic. However, there is no reported volcanic activity in the area where the source appears to be located.</p><p> </p>

scholarly journals Electromagnetic-wave radiation due to diastrophism of magma dike growth in Izu-Miyake volcanic eruptions in Japan in 2000

2001 ◽  
Vol 1 (1/2) ◽  
pp. 43-51 ◽  
Author(s):  
M. Hata ◽  
I. Takumi ◽  
H. Yasukawa
Keyword(s):  
Electromagnetic Wave ◽  
Magnetic Flux ◽  
Volcanic Activity ◽  
Electromagnetic Waves ◽  
Volcanic Eruptions ◽  
Wave Radiation ◽  
Gps Data ◽  
Radiation Mechanisms ◽  
The Earth ◽  
Gps Observation

Abstract. A large 10 cm per day diastrophism of the crust was experienced between Kozu and Niijima Islands during the Izu-Miyake volcanic eruptions in Japan on 3–4 August 2000. The diastrophism was detected through GPS observation. The seismometer also complied a swarm of earth-quakes at this time. Our electromagnetic wave data, observed at 223 Hz at the Omaezaki site, about 110 km and 150 km northwest of the Kozu and Miyake Islands, respectively, detected a clear, anomalous magnetic flux radiation that corresponded well with the seismographic and GPS data. Similar radiation was received for about one week preceding the big volcanic eruption that occurred on 18 August 2000. These observations indicate that the electromagnetic wave monitoring system has the potential to monitor and/or warn of volcanic activity, and the facts disclose one of the mysterious radiation mechanisms of electromagnetic waves emitted from the Earth.

Ground Deformation of Mayon Volcano Revealed by GPS Campaign Survey

2015 ◽  
Vol 10 (1) ◽  
pp. 106-112
Author(s):  
Akimichi Takagi ◽  
◽  
Kenji Fujiwara ◽  
Takahiro Ohkura ◽  
Artemio C. Luis ◽  
...  
Keyword(s):  
Volume Change ◽  
Ground Deformation ◽  
Source Parameters ◽  
Pressure Source ◽  
Mayon Volcano ◽  
Observation Network ◽  
Preparation Stage ◽  
Gps Observation ◽  
Continuous Gps ◽  
Do So

Determining the location and the amount of volume change of the pressure source beneath a volcano during the eruption preparation stage is an important issue in monitoring the magma accumulation. To do so, we have implemented a GPS campaign survey network around the Mayon volcano and monitored ground deformation since 2005. Rapid grounddeflating deformation was detected accompanied by the 2009 eruption. The Mogi model pressure source was estimated to be 8.5 km deep beneath the summit and the amount of volume change –13 × 106 m3. In magma accumulation preceding the 2009 eruption, ground deformation showed a weak inflationary trend, but it was difficult to evaluate the source parameters definitively. After the 2009 eruption, no deformation has been detected by the Continuous GPS observation network since 2012. Trend of many baselines of continuous and campaign network turned to extension since 2014. Magma may have started accumulating beneath the Mayon volcano.

scholarly journals Crustal deformations associated with the great Sumatra-Andaman earthquake deduced from continuous GPS observation

2006 ◽  
Vol 58 (2) ◽  
pp. 127-139 ◽  
Author(s):  
Manabu Hashimoto ◽  
Nithiwatthn Choosakul ◽  
Michio Hashizume ◽  
Shuzo Takemoto ◽  
Hiroshi Takiguchi ◽  
...  
Keyword(s):  
Gps Observation ◽  
Continuous Gps ◽  
Andaman Earthquake

A ground-motion prediction model for small-to-moderate induced earthquakes for Central and Eastern United States

2021 ◽  
pp. 875529302110160
Author(s):  
Zoya Farajpour ◽  
Shahram Pezeshk
Keyword(s):  
United States ◽  
Ground Motion ◽  
Gulf Coast ◽  
Hazard Evaluation ◽  
Eastern United States ◽  
Induced Earthquakes ◽  
Ground Acceleration ◽  
Mixed Effect ◽  
Ground Motion Model ◽  
Tectonic Earthquakes

This study presents a new ground motion model (GMM) for small-to-moderate potentially induced earthquakes for Central and Eastern United States (CEUS). We used a hybrid empirical model as the base model, which was developed and calibrated for tectonic events in Central and Eastern North America (CENA) as part of the Next-generation Attenuation-East (NGA-East) project. We calibrated the base model using a comprehensive database of potentially induced ground motions with smaller magnitudes and shallower depths than tectonic earthquakes, excluding all earthquake events and stations within the Gulf Coast region. We determined the model functional form coefficients using a mixed-effect regression procedure. The proposed GMM is derived for the peak ground acceleration and response-spectral ordinates at periods ranging from 0.01 to 10.0s, moment magnitudes ranging from 3.0 to 5.8, and hypocentral distances up to 200km. The performance of the proposed GMM is evaluated through a set of comprehensive residual analyses. Furthermore, we compared the proposed GMM with recently published GMMs with the observed data for CEUS. The proposed GMM could apply in long-term and short-term US Geological Survey National Seismic Hazard Maps and for the hazard evaluation of induced seismicity.

scholarly journals A block-fault model for deformation of the Japanese Islands derived from continuous GPS observation

2000 ◽  
Vol 52 (11) ◽  
pp. 1095-1100 ◽  
Author(s):  
Manabu Hashimoto ◽  
Shin’ichi Miyazaki ◽  
David D. Jackson
Keyword(s):  
Fault Model ◽  
Gps Observation ◽  
Continuous Gps ◽  
Japanese Islands

scholarly journals A review framework of how earthquakes trigger volcanic eruptions

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Gilles Seropian ◽  
Ben M. Kennedy ◽  
Thomas R. Walter ◽  
Mie Ichihara ◽  
Arthur D. Jolly
Keyword(s):  
Volcanic Activity ◽  
Closed System ◽  
Current Knowledge ◽  
Volcanic Eruptions ◽  
Hydrothermal Systems ◽  
Earthquake Triggering ◽  
Tectonic Earthquakes ◽  
Underlying Mechanisms ◽  
Review Current ◽  
Magma Viscosity

AbstractIt is generally accepted that tectonic earthquakes may trigger volcanic activity, although the underlying mechanisms are poorly constrained. Here, we review current knowledge, and introduce a novel framework to help characterize earthquake-triggering processes. This framework outlines three parameters observable at volcanoes, namely magma viscosity, open- or closed-system degassing and the presence or absence of an active hydrothermal system. Our classification illustrates that most types of volcanoes may be seismically-triggered, though require different combinations of volcanic and seismic conditions, and triggering is unlikely unless the system is primed for eruption. Seismically-triggered unrest is more common, and particularly associated with hydrothermal systems.

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