Repeated seismic reflection measurements in the Kakkonda geothermal field

Matsushima, Jun; Yokota, Toshiyuki; Okubo, Yasukuni; Rokugawa, Shuichi; Tanaka, Keiji; Tsuchiya, Terumitsu; Narita, Norifumi; Tani, Kazuyuki

doi:10.1016/s0377-0273(03)00286-5

Cited by 7 publications

(2 citation statements)

References 18 publications

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“…Swave splitting waves and coda-Q analyses have succeeded in detecting a small change of the structure around active seismic areas (e.g., Hiramatsu et al, 2000;Saiga et al, 2003;Tadokoro and Ando, 2002). Repeated seismic reflection measurements in the Kakkonda geothermal area also found structure changes around micro-seismic zones (Matsushima et al, 2004). These previous studies indicate that temporal changes of the crustal structure are related with seismic/volcanic activities and plate motions.…”

Section: Introductionmentioning

confidence: 92%

Temporal changes in seismic velocity of the crust around Iwate volcano, Japan, as inferred from analyses of repeated active seismic experiment data from 1998 to 2003

et al. 2005

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We have examined temporal changes in seismic velocity of the crust through repeated active seismic experiments at Iwate volcano, Japan, where a significant volcanic activity and an M6.1 earthquake were observed in 1998. We apply a cross spectrum moving window technique to seismic data recorded at eight stations for the six explosions detonated from1998 to 2003. The seismic velocity at the frequency range of 3-9 Hz decreased by about 1% during the three months including the occurrence of M6.1 earthquake. The seismic velocity gradually increased, and about one third of the decrease was recovered by 2002. Then, the seismic velocity decreased again in 2003. Spatio-temporal changes in the volumetric strains predicted from the M6.1 fault mechanism and the volcanic pressure sources are well correlated with the seismic velocity changes observed in 1998. However, the predicted stress fields are not completely matched with the observed velocity changes from 1998 to 2003. This inconsistency may be due to unknown regional tectonic stress field and/or localized stress fields induced by volcanic pressure sources. It should be noted that the observed velocity changes indicate frequency dependent characteristics although the mechanism is not yet understood.

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Section: Introductionmentioning

confidence: 92%

Temporal changes in seismic velocity of the crust around Iwate volcano, Japan, as inferred from analyses of repeated active seismic experiment data from 1998 to 2003

et al. 2005

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“…SP탐사는 지열 자원이 풍부한 일본 등에서 꾸준히 연구되어 오고 있다 (Corwin et al, 1979;Matsushima et al, 2000). 지 열 저류층 유체는 각기 다른 온도와 염도를 가지고 존재하게 되며, 이 차이가 클 수록 유동 전위가 높게 나타난다 (Cioni et al, 1992).…”

Section: 특히 지열 발전 저류층에서의 유체 유동을 탐사하기 위한unclassified

Modeling of SP responses for geothermal-fluid flow within EGS reservoir

Song¹,

Kim²,

Nam³

et al. 2015

Geophysics and Geophysical Exploration

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Self-potential (SP) is sensitive to groundwater flow and there are many causes to generate SP. Among many mechanisms of SP, pore-fluid flow in porous media can generate potential without any external current source, which is referred to as electrokinetic potential or streaming potential. When calculating SP responses on the surface due to geothermal fluid within an engineered geothermal system (EGS) reservoir, SP anomaly is usually considered to be generated by fluid injection or production within the reservoir. However, SP anomaly can also result from geothermal water fluid within EGS reservoirs experiencing temperature changes between injection and production wells. For more precise simulation of SP responses, we developed an algorithm being able to take account of SP anomalies produced by not only water injection and production but also the fluid of geothermal water, based on three-dimensional finiteelement-method employing tetrahedron elements; the developed algorithm can simulate electrical potential responses by both point source and volume source. After verifying the developed algorithm, we assumed a simple geothermal reservoir model and analyzed SP responses caused by geothermal water injection and production. We are going to further analyze SP responses for geothermal water in the presence of water production and injection, considering temperature distribution and geothermal water flow in the following research.

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Effect of spatial sampling on time-lapse seismic monitoring in random heterogeneous media

Matsushima¹,

Nishizawa²

2020

Active Geophysical Monitoring

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Repeated seismic reflection measurements in the Kakkonda geothermal field

Cited by 7 publications

References 18 publications

Temporal changes in seismic velocity of the crust around Iwate volcano, Japan, as inferred from analyses of repeated active seismic experiment data from 1998 to 2003

Temporal changes in seismic velocity of the crust around Iwate volcano, Japan, as inferred from analyses of repeated active seismic experiment data from 1998 to 2003

Modeling of SP responses for geothermal-fluid flow within EGS reservoir

Effect of spatial sampling on time-lapse seismic monitoring in random heterogeneous media

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