MIS03-01

日本地球惑星科学連合2016年大会

The preliminary study of the high-sampling coseismic groundwater level changes in ML 6.4
Tainan earthquake, Feb. 6th 2016
*WENCHI LAI1, ShihJung Wang2, KuoChin Hsu3, Naoji Koizumi4
1.Disaster Prevention Research Center, National Chengkung University, Taiwan, 2.GeotechnicalEngineering Research Center Sinotech Engineering Consultants, INC., Taiwan, 3.Department of
Resources Engineering, National Chengkung University, Taiwan, 4.Department of Ecosystem Studies,
School of Environmental Science, The University of Shiga Prefecture
The different response by various natural stimuli and processes (tidal force, barometric loading,ground shaking and crustal strain) were used as the elements of the hydraulic information in theearthquake induced groundwater level changes. Using the natural force to act as naturally recurring
stimuli to provide a sufficiently varied distribution of excitations in time and space, andrepresented the hydro-geological changes responses to the earthquake processes. The purposes ofthis study are to analyze the recently observation results of the earthquake induced pre-seismic /co-seismic variation of groundwater level ML 6.4 Tainan earthquake, Feb. 6th 2016. The analysis of
the high-sampling water level responses be used to estimate the mechanical properties of theaquifer. Comparison the observation high-sampling water level changes in the each event, offers theopportunity to discussion the possible mechanism of the hydrologic response to earthquake. Some of
the coseismic groundwater level changes can be explained as the poroelastic responses to theearthquake-induced volumetric strain changes inferred from the fault dislocation models. But theother changes can not be explained by the volumetric strain changes either qualitatively or
quantitatively. We regarded the coseismic static volumetric strain change and the groundacceleration as the main factors to cause the coseismic groundwater level changes. The study
provides some information for the pre-seismic / co-seismic mechanism but more investigations are
required
Keywords: Coseismic Changes, Groundwater, Earthquake©2016. Japan Geoscience Union. All Right Reserved.

- MIS03-01 -MIS03-01©2016. Japan Geoscience Union. All Right Reserved.

日本地球惑星科学連合2016年大会- MIS03-01 -MIS03-02

日本地球惑星科学連合2016年大会

Seismo-conductivity Anomalies: A case study of the M6.4 Meinong earthquake on Feb. 6, 2016
in Taiwan*Chieh-Hung Chen1, Cheng-Horng Lin2, Chun-Rong Chen3
1.Department of Earth and Environmental Sciences, National Chung Cheng University, Taiwan,
2.Institute of Earth Sciences, Academia Sinica, Taipei, Taiwan, 3.Department of Earth Sciences,
National Central University, Chung-Li, Taiwan
Anomalous phenomena of conductivity enhancements have been repeatedly observed before many
earthquakes in Taiwan through orientations of the Parkinson vectors derived from 3-component
magnetic data via the magnetic transfer function. Meanwhile, depths of conductivity anomalies canbe roughly estimated while the skin effect is conducted into the frequency-dependent parameters ofthe magnetic transfer function. Locations of seismo-conductivity anomalies are determined by using
anomalous orientations of the Parkinson vectors from three magnetic stations. Through the 3-year
observation, locations of conductivity enhancements and hypocenters are often comparable that is
obtained. The Meinong earthquake with the magnitude of 6.4 occurred in the southern part of Taiwan
on Feb. 6 2016. High-conductivity anomalies associated with the M6.4 Earthquake were found in twoareas. Anomalies located at the depth of 15 km were observed very close to the main shock on Jan.
31-Feb. 3, 2016. In contrast, the other anomalies at the depth of 30 km on Feb. 2-Feb. 6, 2016 arelocated at the northern part of the main shock in agreement with aftershocks.
Keywords: Pre-earthquake anomalous phenomena, Meinong earthquake, Seismo-conductivity anomalies©2016. Japan Geoscience Union. All Right Reserved.

- MIS03-02 -MIS03-03

日本地球惑星科学連合2016年大会

Multi parameters observations of pre-earthquake signals associated with M6.4 of Feb 06,
2016 in Taiwan. Preliminary results.
*Dimitar Ouzounov1, Lou C. Lee2, J.Y. Liu3, C.H Chen3, Sergey Pulinets4, Menas Kafatos1
1.Center of Excellence in Earth Systems Modeling & Observations (CEESMO) , Schmid College of
Science & Technology Chapman University, Orange, California, USA, 2.Institute of Earth Sciences,
Academia Sinica, Taiwan, 3.Institute of Space Science, National Central University, Taiwan, 4.Space
Research Institute, Russian Academy of Sciences, Moscow, Russia
We are conducting validation on temporal-spatial pattern of multi parameter signals with
pre–earthquake origin associated with M 6.4 of Feb 02, 2016 earthquake in Taiwan.The continues
analysis of outgoing long-wavelength radiation (OLR) obtained from NPOESS show rapid increase of
OLR on the top of the atmosphere on Jan 1-2, 2016 (2.5 sigma significance for 25 years of analysis)
and probably indicated for a large earthquake preparation process in Taiwan(map is attached). The
time series variations of atmospheric chemical potential, characterizing the ionization processes
inside ABL, show rapid increases during Jan 1-5 and Jan 10-15, 2016 periods. The Gamma network
consisted by 4 stations registered similar anomalous pattern in increasing of the radon level
during period of Jan 10-15, 2016 simultaneously on three of the stations close to the epicenter.
Based on the 3-component geomagnetic data from 3 stations, high-conductivity anomalies were foundin two different periods: i)Jan. 31-Feb. 3, 2016 - the anomalies were observed very close to themain shock and the ii)Feb. 2-Feb. 6, 2016 - anomalies are further North and associated with thefollowed aftershocks. The GIM reveals the TEC significantly enhances over Taiwan on 5 February
2016, one day before the earthquake.
Our preliminary analysis of simultaneous space and grounds measurements associated with M6.4 of Feb
06, 2016 in Taiwan suggest that pre-earthquake phase follows a general temporal-spatial evolution
pattern reviled with multi instruments observations, which has been seen in other large earthquakes
worldwide.
Keywords: earthqauke, precursor, forecasting, prediction©2016. Japan Geoscience Union. All Right Reserved.

- MIS03-03 -MIS03-03©2016. Japan Geoscience Union. All Right Reserved.

日本地球惑星科学連合2016年大会- MIS03-03 -MIS03-04

日本地球惑星科学連合2016年大会

Precursory gas geochemical and gamma rays anomalies prior to the 2016 M6.4 Meinong
earthquake, southern Taiwan
Precursory gas geochemical and gamma rays anomalies prior to the 2016 M6.4 Meinong
earthquake, southern Taiwan*Fu Ching1,2、Lee Lou1、Yang Tsanyao2、Wang Peng1、Liu Tsung2、Walia Vivek3、Chen Cheng2、Lin Cheng1、Lai Tzu4、Giuliani Gioacchino 5、Ouzounov Dimitar6*Ching Chou Fu1,2, Lou Chuang Lee1, Tsanyao Frank Yang2, Peng Kang Wang1, Tsung Kwei Liu2, Vivek
Walia3, Cheng Hong Chen2, Cheng Horng Lin1, Tzu Hua Lai4, Gioacchino Giuliani5, Dimitar Ouzounov6
1.Institute of Earth Sciences Academia Sinica、2.Department of Geosciences, National Taiwan
University、3.National Center for Research on Earthquake Engineering, NARL、4.Central Geological
Survey, MOEA、5.Permanent Foundation G. Giuliani, L'Aquila、6.Chapman University, One University
Drive, Orange
1.Institute of Earth Sciences Academia Sinica, 2.Department of Geosciences, National Taiwan
University, 3.National Center for Research on Earthquake Engineering, NARL, 4.Central Geological
Survey, MOEA, 5.Permanent Foundation G. Giuliani, L'Aquila, 6.Chapman University, One University
Drive, Orange
Taiwan is tectonically situated in a terrain resulting from the oblique collision between thePhilippine Sea plate and the continental margin of the Asiatic plate, with a continuous stresscausing the density of earthquakes and faults. The continuous observations of soil radon forearthquake studies have been recorded and are compared with the data from gamma rays observations.
Some anomalous high radon concentrations and gamma-ray counts at certain times can be identified. A
significant increase of soil radon concentrations was observed at Gukeng (GK), Chunglun (CL) and
Pingtung (PT) station, and an increase in gamma-ray counts at the Chung Cheng University (CCUG) was
also observed around two weeks before the Meinong Earthquake (ML = 6.4, February 6, 2016) insouthern Taiwan. The precursory changes in multi-parameters monitoring may reflect the preparation
stage of a large earthquake. And, precursory signals are observed simultaneously that can conduce
to expect the approximate location of the impending earthquake with high confidence. The continuous
monitoring on the multiple parameters can improve our understanding of the relationship between theobserved radon and gamma-ray variations and the regional crustal stress/strain in the area.
キーワード：radon、gamma rays、Meinong Earthquake
Keywords: radon, gamma rays, Meinong Earthquake©2016. Japan Geoscience Union. All Right Reserved.

- MIS03-04 -MIS03-05

日本地球惑星科学連合2016年大会

Thermal InfraRed satellite surveys over Japanese seismic area applying Robust Satellite
Techniques on MTSAT observations*Nicola Genzano1,2, Carolina Filizzola3, Katsumi Hattori2,4, Mariano Lisi1,4, Rossana Paciello3,
Nicola Pergola3, Valerio Tramutoli1,3,4
1.School of Engineering, University of Basilicata, Potenza, Italy , 2.Graduate School of Science,
Chiba University, Chiba, Japan, 3.Institute of Methodologies for Environmental Analysis of the
National Research Council, Tito Scalo (PZ), Italy, 4.International Space Science Institute,
Beijing, China
Since 2001, the general change detention approach, named Robust Satellite Techniques (RST), hasbeen applied to explore the fluctuations of Earth’s thermally emitted radiation, observed bysatellite sensors operating in the thermal infrared (TIR) spectral range in possible relationshipwith the preparation phases of major earthquakes. Used in combination with RETIRA (Robust Estimatorof TIR Anomalies) index, RST data analysis approach showed good ability to discriminate anomalous
TIR signals possibly associated to seismic activity, from the normal variability of TIR signal due
to other causes (e.g. meteorological).
Up to now, RST has been implemented on different TIR satellite sensors on board polar (NOAA andEOS) and geostationary (like, MSG, GOES, GMS and MTSAT) platforms, to investigate the preparation
phases of earthquakes of different magnitudes occurred in several seismogenic areas around theworld (e.g. Italy, California, Greece, Turkey, Taiwan, etc.).
In this paper, the RST data analysis approach has been implemented on TIR satellite records
collected over Japan by the geostationary satellite sensor MTSAT (Multifunctional Transport
SATellites). RETIRA index was used to identify Significant Sequences of TIR Anomalies (SSTAs) on along observation period. Significance of the correlation existing among SSTAs and earthquakes (withM≥4) occurrence was investigated in order to evaluate the possible contribute of such observations
to a multi-parametric t-DASH (time-Dependent Assessment of Seismic Hazard) system for short-term
seismic hazard forecasting.
Keywords: Earthquakes, TIR anomalies, RST analysis, Precursor, t-DASH©2016. Japan Geoscience Union. All Right Reserved.

- MIS03-05 -MIS03-06

日本地球惑星科学連合2016年大会

Spatiotemporal characteristics of the geomagnetic diurnal variation anomalies prior to the2011 Tohoku earthquake (Mw9.0)
Spatiotemporal characteristics of the geomagnetic diurnal variation anomalies prior to the2011 Tohoku earthquake (Mw9.0)*Han Peng1,3、Hattori Katsumi 1、Huang Qinghua 2*Peng Han1,3, Katsumi Hattori1, Qinghua Huang2
1.Department of Earth Sciences, Graduate School of Science, Chiba University、2.Department ofGeophysics, School of Earth and Space Sciences, Peking University, Beijing, China、3.Institute of
Statistical Mathematics, Tokyo, Japan
1.Department of Earth Sciences, Graduate School of Science, Chiba University, 2.Department ofGeophysics, School of Earth and Space Sciences, Peking University, Beijing, China, 3.Institute of
Statistical Mathematics, Tokyo, Japan
Xu et al., 2013 and Han et al., 2015 have reported unusual behaviors of geomagnetic diurnal
variation (GDV) in the vertical component prior to the 2011 off the Pacific coast of Tohoku
earthquake (Mw 9.0). To make a better understanding of this phenomenon, temporal-spatial analyses
of GDV have been applied in this study. Geomagnetic data of long-term observations at 17 stationsin Japan have been analyzed using the same method in Han et al. 2015. Ratios of diurnal variation
range between the reference station KAK and the target stations have been computed. After removing
seasonal variations, the 15-day mean values of the ratios in the vertical component shows a clear
anomaly exceeding the statistical threshold about 2 months before the mega event at both ESA andMIZ stations in the Tohoku Region. Locations of anomalies in spatial distribution show a goodcorrelation with the epicenter of the Mw 9.0 earthquake. These spatiotemporal results are
consistent with those obtained from other independent observations such as groundwater level andGPS displacements. The coupling of multiple pre-earthquake phenomena may help to understand the
preparation process of a mega earthquake in the subduction zone.
キーワード：seismo-magnetic phenomena、anomalous geomagnetic diurnal variation、coupling ofmultiple pre-earthquake phenomena、the Tohoku earthquake
Keywords: seismo-magnetic phenomena, anomalous geomagnetic diurnal variation, coupling of multiple
pre-earthquake phenomena, the Tohoku earthquake©2016. Japan Geoscience Union. All Right Reserved.

- MIS03-06 -MIS03-07

日本地球惑星科学連合2016年大会

Ionospheric anomalies instantly before three large earthquakes in Chile detected with GPS
observations*Liming He1,2, Kosuke Heki2
1.Institute for Geo-informatics & Digital Mine Research, College of Resources and Civil
Engineering, Northeastern Univ., China, 2.Department of Earth and Planetary Sciences, Hokkaido
Univ., Japan
In this work, the ground-based permanent GPS stations were used to study ionospheric total electron
content (TEC) response to three large earthquakes in Chile: the Mw8.3 Illapel earthquake of 16
September 2015, the Mw8.2 Iquique earthquake of 01 April 2014, and the Mw8.8 Maule earthquake of 27
February 2010. The GPS arrays around the epicenters provide rare opportunities to investigate thecomprehensive near-field preseismic TEC responses to three huge earthquakes in South America. Basedon the GPS absolute VTEC technique and Akaike’s information criterion (AIC) method, the spatial
distribution of ionospheric anomalies have been analyzed for the first time, especially in theheight direction. The results showed that the positive anomalies occurred at an altitude of ~200km, while the negative anomalies occurred at an altitude of ~350 km for the large earthquakes inthe south hemisphere. The negative anomalies have a lager distribution than positive anomalies. A
well consistency exists between the observation and the simulation result from C.L. Kou et al.
(2014). The distribution of both positive and negative anomalies were mainly controlled by thegeomagnetic field and magnetic latitude of epicenter. Moreover, we analyzed the VTEC variations
during non-seismic activity period, and compared the VTEC changes originated form strong seismic
activity with the VTEC changes induced by geomagnetic storm.
Acknowledgements: This study was funded by China Scholarship Council (CSC) and partially funded by
the National Natural Science Foundation of China (grant no. 41104104). We thank C. Vigny (ENS) for
providing GNSS data in Chile of his group. We thank the Argentine national geographic institute(IGNA) for providing GPS data of RAMSAC network, and the Brazilian Institute for Geography andStatistics (IBGE) for providing GPS data of RBMC network. We thank IGS (www.igs.org) and UNAVCO(www.unavco.org) for making GNSS data available.
Keywords: GPS TEC, large earthquake, preseismic anomaly, spatial distribution©2016. Japan Geoscience Union. All Right Reserved.

- MIS03-07 -MIS03-08

日本地球惑星科学連合2016年大会

Modification of Ionosphere before Large Earthquakes- Report of Ionosphere Precursor Study
Task Group*Koichiro Oyama1,2, R Ryu4, C.H. Chen5, L Bankov8, D Minakshi3, H Liu2,7, J.Y. Liu6, T Kodama9
1.Plasma and Space Science Center,National Cheng Kung University, 2.International Center for Space
Weather Study and Education, Kyushu University, 3.Physics department, Gauhati University, Assam,
India , 4.Satellite Technology Research Center, Korea Advanced Institute of Science and Technology,
Daejon, Republic of Korea, 5. Department of Earth Science, National Cheng Kung University, Tainan,
Taiwan, 6.Institute of Space Science, National Central University, Chung-Li, Taiwan, 7.Departmentof Earth and Planetary Sciences, Kyushu University, Fukuoka, Japan, 8. Bulgarian Academy of
Sciences, Sofia, Bulgaria, 9.Japan Aerospace Exploration Agency, Tsukuba, JapanThe current status of ionospheric precursors associated with large earthquakes (EQs) is summarized
in this paper as an outcome of a joint endeavor of the “Ionosphere Precursor Study Task Group,”
which was formed with the support of the Mitsubishi Foundation in 2014–2015. The group aims topromote the study of ionosphere precursors to EQs by trying to provide new findings, to prepare fora future EQ-dedicated satellite constellation, which is essentially needed to study the global
morphology of ionosphere precursors, and to determine whether short term EQ prediction is possible.
The first part of the manuscript reviews the ionosphere precursors that have been reported
previously. Problems and specific research subjects that have become clearer from our one-year
project are described. Satellite missions that are planned or are going to be launched soon for EQ
studies are briefly described in the final part of the manuscript.
Keywords: ionopshere, earthquake, wave

©2016. Japan Geoscience Union. All Right Reserved.

- MIS03-08 -MIS03-09

日本地球惑星科学連合2016年大会

Theoretical Simulations of Electric Current Effects on the Ionospheric Plasma Structure*Charles Lin1, Jann-Yenq Liu2, Chuan-Ping Lein1, Chia-Hung Chen1
1.Department of Earth Science, National Cheng Kung University, 2.Institute of Space Science,
National Central University, Chung-Li, Taiwan
Recent studies show ionospheric plasma density modifications due to lithosphere and atmosphereactivities. One of the possible mechanisms for the ionosphere modifications might be direct current
transmission effect to the ionospheric dynamo region. On the other hand, the disturbances could
also affect the ionosphere by generating atmospheric disturbance waves that modify the neutral
winds and thus affect the ionospheric dynamo and electron density. In this study, simulations of
the direct current and disturbance wind dynamo effects are carried out using a coupledthree-dimensional global ionosphere electrodynamic model. Simulations carried out by inclusion of
the upward/downward transmission of direct electric current at 85 km altitude with various areas ofcurrent injections, indicate negative/positive TEC effects. The simulations for different local
time sectors are also carried out showing that the effect is most prominent at dusk followed bythat of at afternoon and noon periods. The simulations will also be compared with GPS-TEC
observations of pre-seismic anomalies.
Keywords: Coupled Ionosphere Electrodynamic Simulation, Electric Current, Pre-seismic Ionosphere
Anomalies©2016. Japan Geoscience Union. All Right Reserved.

- MIS03-09 -MIS03-10

日本地球惑星科学連合2016年大会

Co-rupture, quasi-coseismic, and post-seismic EM fields generated by the rupture processof a finite fault embedd in a porous medium*Hengxin Ren1, Qinghua Huang2, Xiaofei Chen1
1.Sch. Earth Space Sci., Uinv. Sci. Tech. China, Hefei 230026, China, 2.Dept. Geophysics, Peking
Univ., Beijing 100871, China
The electrokinetic effect related with the electric double layer between rock and fluid is one of
the most possible generation mechanisms of earthquake-related electromagnetic (EM) signals.
Previous numerical simulation studies of earthquake-related EM signals have indicated that theelectrokinetic effect is able to generate co-rupture and coseismic EM fields as well as
post-seismic electric fields. However, the amplitudes of the simulated co-rupture EM signals areunder the natural EM noise levels. This means they are unobservable. Thanks to the improvement in
the instrument and approach applied in the field observation of EM anomalies, reports on the
co-rupture electric or magnetic signals finally appeared in recent years although such reports arevery rare. Quasi-coseismic EM signals which are synchronous with seismic arrival have also beenrecorded in field observation. According to previous simulations on the electrokinetic effect, they
are thought to be the coseismic EM fields, which are local responses to the seismic arrivals in a
porous medium. In this study, we carry out numerical simulations of the electrokinetically coupledseismic and EM wavefields generated by a finite fault in a layered model consisting of porous andsolid materials. Results confirm that the electrokinetic effect does can generate observableco-rupture EM signals, and the observability depends on the epicentral distance, properties of themedium where the fault is located, and local EM noise levels. It is shown quasi-coseismic EM
signals can be generated even if the top layer, which is above the ground water level, is assumed
to be a solid layer. The quasi-coseismic EM signals at least are partially contributed by theevanescent EM waves generated at the shallow subsurface interfaces. The evanescent EM waves are
sensitive to the properties of the shallow subsurface fluid. Besides the radiation EM waves ofinterface response, the evanescent EM waves possibly also have some potential applications
associated with the shallow subsurface fluids. Our results also show that electrokinetic effect cangenerate post-seismic electric and magnetic fields. They are presumably induced by the
low-frequency fluid diffusion after the earthquake. The post-seismic magnetic field has not been
identified in previous simulations on the electrokientic effect, because its generation requires asufficiently strong medium heterogeneity, which the uniform porous half-spaced utilized in previous
simulations cannot provide. Further studies on the evanescent EM waves and the EM fields associatedwith the fluid diffusion caused by the stress change may provide a better understanding andinterpretation of the earthquake-related EM signals.

Acknowledgements: This study is supported by the National Natural Science Foundation of China(Grant Nos. 41274054, 41274075 and 41274053).
Keywords: co-rupture EM signals, quasi-coseismic EM signals, post-seismic EM fields, electrokinetic
effect, rupture process of a finite fault©2016. Japan Geoscience Union. All Right Reserved.

- MIS03-10 -MIS03-11

日本地球惑星科学連合2016年大会

National center of earthquake prediction experiment in China*Qinghua Huang1, Xiaodong Zhang2
1.Peking University, 2.Institute of Earthquake Science, CEA
China is one of the countries which have the earliest reports on earthquake-related phenomena.
There are about 50-year continuous observation data in China up to now, which provides a valuable
database for earthquake-related study. China is also a pioneer country for empirical earthquake
prediction. Therefore, earthquake prediction experiment in China would be interested broadly byinternational communities of geosciences.
Although there had been some earthquake prediction experiments in China about 20 years before, due
to the great debates in earthquake prediction and the discontinuity of funding support, all theseearthquake prediction experiments are not on operation at the current stage. After the 2008 Ms8.0
Wenchuan earthquake in Sichuan, China, the Chinese government evaluated the situation of earthquake
prediction and hazard mitigation. As the national agency of earthquake study, China Earthquake
Administration (CEA) established the national center of earthquake prediction experiment in 2015,
including sub-centers in Yunnan and Sichuan. The supporting institution of national center isInstitute of Earthquake Science, CEA. The national center will provide an open, cooperative,
dynamic platform for earthquake prediction research. We will summarize the main goal and task ofthe national center of earthquake prediction experiment in Yunnan and Sichuan, China.
This study is supported by the National Natural Science Foundation of China (41574104).
Keywords: Earthquakes, prediction experiment, seismic hazard©2016. Japan Geoscience Union. All Right Reserved.

- MIS03-11 -MIS03-12

日本地球惑星科学連合2016年大会

A Summary of iSTEP (integrated Study and Test of Earthquake Precursor) projects*Jann-Yenq Liu1, Yi-Ben Tsai2, Chieh-Hung Chen3, Yuh-Ing Chen4
1.Institute of Space Science, National Central University, Taiwan, 2.Department of Earth Sciences,
National Central University,Taiwan, 3.Department of Earth and Environmental Sciences, National
Chung Cheng University, Taiwan, 4.Institute of Statistics, National Central University, Taiwan
After the 21 September 1999 M7.6 devastating earthquake, a program entitled the integrated Search
for Taiwan Earthquake Precursor (iSTEP-1, 2002/4/1–2006/3/31), which consists of a main project andfive sub-projects, was conducted to search credible precursors in seismological variations,geomagnetic and gravity fields, ground surface deformations, and ionospheric electron density
anomalies, as well as to evaluate the statistical significance of observed precursors in Taiwan.
Results reveal that anomalies in P-wave velocity, ground surface deformation, geomagnetic field
intensity, ionospheric electron density could appear few years, months, and days before large
earthquakes in Taiwan, respectively. An integrated ground-based seismo-electromagnetic observation
system, including eight networks of magnetometers, electrode arrays, corona probes, FM tuners,
Doppler sounding systems, ionosondes, GPS receivers, and all sky cameras, has been constructed androutinely operating to monitor earthquake precursors in the lithosphere, atmosphere, and ionosphereand to find possible lithosphere-atmosphere-ionosphere coupling in the Taiwan area. Several
statistical analyses were developed to validate the observed anomalies to be credible precursors.
Due to its worldwide availability, the statistical results showed that the ionospheric total
electron content (TEC) derived by ground-based GPS receivers were most likely to be a credible
precursor. Succeeding the iSTEP-1, the iSTEP-2 (integrated Study for Taiwan Earthquake Precursors,
2006/8–2012/7) project adding with satellite observations was conducted to have a longer time
period for data collection and analysis, as well as to develop physical and statistical models.
Although it was not officially funded but supported by basic ionospheric research projects, theintegrated ground-based observation still has been operating uninterruptedly. Many new observations
possibly related to seismo-lithospheric precursors of the earth’s surface magnetic field and the
GPS surface deformation, seismo-atmospheric precursors of the infrasound signal, andseismo-ionospheric precursors (SIPs) in the electron density profile, the electron temperature, ion
density, and neutral temperature probed by satellites were reported. The TEC in the global
ionosphere map (GIM) routinely published (with a 2- or 4-day time delay) allows us to monitor
temporal SIPs at a specific location, and to conduct spatial analysis discriminating the observed
SIPs from global effects, such as solar flares, magnetic storms, etc. Statistical analyses for
detecting both temporal and spatial precursors in the ionospheric TEC are developed. Meanwhile,ionospheric model simulations are also introduced to find causal mechanisms explaining the observed
SIPs. The iSTEP-3 (integrated Study for Taiwan Earthquake Precursors, 2012/8–2016/7), which is
proposed to focus on the SIP study, consisting of a main project and three sub-projects is formallyfunded. The main project continues to operate the integrated ground-based observation system,
develops physical models, and compares model simulations with observed precursors, while the three
sub-projects aim to develop a near real-time GIM with a 4-hour time delay for worldwide SIP
monitoring, to monitor lithosphere, atmosphere, and ionosphere precursors, to find the precursor
link, and to conduct earthquake hazard assessment with observed precursors, respectively.
Keywords: iSTEP, earthquake prediction, earthquake precursor, total electron content, GPS TEC©2016. Japan Geoscience Union. All Right Reserved.

- MIS03-12 -MIS03-P01

日本地球惑星科学連合2016年大会

Earthquake-induced electromagnetic field due to electrokinetic effect*Yongxin Gao1, Hengshan Hu2, Xiaofei Chen3
1.School of Civil Engineering, Hefei University of Technology, Hefei, China, 2.Department of
Astronautics and Mechanics, Harbin Institute of Technology, Harbin, China, 3.School of Earth andSpace Sciences, University of Science and Technology of China, Hefei, China
Electromagnetic fields generated by earthquake events were usually reported and have drawn a lot of
attentions. They can be detected before, during and after the seismic arrivals after earthquake
rupture started, and are referred to as the co-rupture, coseismic and post-seismic EM signals,
respectively. The co-rupture EM signal is of great importance since it arrives earlier than theseismic waves, especially the destructive shear and surface waves and has potentials in earthquake
early warning and hazard reduction. The coseismic EM signal arriving simultaneously with theseismic waves are also valuable since it contains the information of the subsurface medium in thevicinity of the EM sensors. However, how these kind EM signals are generated is still
controversial. Several possible mechanisms have been proposed to explain the earthquake-induced EM
signals, e.g., the electrokinetic effect, the piezoelectric effect, the motional induction effect,
etc.
In this study, we present the theoretical simulations of the earthquake-induced EM signals on thebasis of the electrokinetic effect. This result shows that due to the electrokinetic effect theearthquake can generate co-rupture EM signal, which arrives immediately after the onset of theearthquake and much earlier than the seismic arrivals. It arrives at different EM sensors
simultaneously. The earthquake can also generate coseismic EM field which arrives simultaneouslywith the seismic waves. Besides, our simulations indicate that when the earthquake fault rupturing
stops and the seismic waves pass far away, the magnetic field vanishes while the electric fieldnear the fault remains, decaying slowly and lasting for hundreds of seconds. The near-fault
poseismic electric fields hold similar features to some field observations in literature. We apply
our theoretical simulations to explain the coseismic EM data observed during the 2004 Mw6 Parkfield
earthquake. By using a finite fault source model obtained via kinematic inversion, we calculate theelectric and magnetic responses to the earthquake rupture are calculated. The result shows that thesynthetic electric signals agree with the observed data for both amplitude and wave shape,
especially for early portions of the records after the earthquake. Our simulations supports theelectrokinetic effect as the reasonable mechanism for the generation of the earthquake-induced
electric fields.
This work is supported by the National Natural Science Foundation of China (grants 41474038 and41204039).
Keywords: earthquake, electromagnetic fields, electrokinetic effect©2016. Japan Geoscience Union. All Right Reserved.

- MIS03-P01 -MIS03-P02

日本地球惑星科学連合2016年大会

四成分歪計(SKZ-1)による前兆的変動の検出
Detection of precursory anomalies using the four -component borehole strain meter (SKZ-1)
孔 向陽1、蘇 凱之2、*藤縄 幸雄3、野田 洋一4
Xiangyang Kong1, Kaizhi Su2, *Yukio Fujinawa3, Yoichi Noda4
1.中国山東省地震局、2.中国地殻応力研究所、3.株式会社ミエルカ防災、4.有限会社テラテクニカ
1.Earthquake Administration of Shandong Province, China, 2.Institute of Crustal Dynamics, CEA,
China, 3.Mieruka Bousai LtdEarthquake Administration of Shandong Province, China, 4.Tierra Tecnica
High sensitive crustal monitoring has a long history to investigate anomalous precursory variationsof earthquakes by means of several kinds of sensors as borehole volumetric sensors (Sacks andEvertson,1971), borehole extension sensor by Gladwin (1984), three component volumetric strain
meter by Sakata (2004) and Ishii and Yamauchi (2007). In China the four component strain meter withhigh performance was developed by Su Kaichi (1977) and has been used in earthquake-prone provinces
since 2006.The configuration of four sensing units at intervals of 45 degree provides a simple
indicator (consistent factor) of the sensor functioning and regime of the crust assumed to be plain
strain in normal state to detect candidates of anomalous variation without little ambiguities. The
observation at ten sites in several provinces of China for some 10 years has proved profitableperformance of the sensor: high stability and high degree of resolution to detect local andregional anomalous variations near hypocenter. In the normal stage the variations consist of steady
diurnal variations due to earth tide, steady trends due to the crustal stress adjustment after
construction of the borehole, and installment of the sensors. There are little urban noises withthe result of the consistent factor being almost constant value of 0.99.
Here we present analyses of anomalous variations detected by use of the correlation coefficient of
two independent plain strain components before two major earthquakes near the network: YiLiang
M5.7earthquake and LuDian M6.5 earthquake. In the imminent sage of the Yiliang earthquake, obvious
strain anomalies with periods of several days, several weeks appeared simultaneously in four
components at the nearest YiLiang site of the epicenter distance15.5km. The correlation
coefficients for those anomalies are well below reaching 0.2 compared with the ordinal value 1.0.
At DaGuan site of larger distance 30km, there appeared no significant anomalies with the factor
remaining the normal value near 0.99 or so. Analyses show that the correlation coefficient can beused to objectively detect anomalies to define the successive stage of earthquake occurrence fromnormal to relaxation stages.
A multiple observations using the four component strain meters, groundwater meters andelectromagnetic sensor are expected to substantially contribute to investigation of the nucleation
process of natural earthquakes. Present finding may contribute to efficient data analysis to detect
candidate of anomalies from using big amount of continuous multiple data with higher sampling rate.
キーワード：歪計、地震前兆現象、検出方法
Keywords: strain meter, pre-seismic anomalies, detection method©2016. Japan Geoscience Union. All Right Reserved.

- MIS03-P02 -MIS03-P03

日本地球惑星科学連合2016年大会

大気用ラドン検出器の開発
Development of radon detector for atmosphere*蜷川 清隆1、山本 勲、岡林 徹2*Kiyotaka Ninagawa1, Isao Yamamoto, Tohru Okabayashi2
1.岡山理科大学理学部応用物理学科、2.千葉科学大学危機管理学部医療危機管理学科
1.Department of Applied Physics, Okayama University of Science, 2.Department of Medical Risk andCrisis Management, Chiba Institute of Science
1995年の兵庫県南部地震では西宮市地下水中ラドン濃度の上昇1や大気中ラドン濃度の上昇（神戸薬科大学）2があったと報告されている。また、東北地方太平洋沖地震では、「福島医科大学（福島市）の放射線施設内の排気モニターのデータが地震前のピークはピーク期間が長く、急激に減少した後，地震が発生した。」と報告されている3。
私達は倉敷鉱山抗内、千葉県において空気中のラドン濃度の連続観測を行っている。倉敷では、家庭用ラドン
測定器SUN NUCLEAR CorporationのRadon Monitor, Modelを、千葉ではPylon社PMT-TEL静電補集型低レベルラド
ンガス検出器（以後TELと略す）を用いている。TELはZnS(Ag) シンチレータと光電子増倍管から構成されている。しかし，α線を検出しているにも係わらず，その出力は連続スペクトルとなっている。その為，計数はディスクリレベルに依存し，カウントのシフトが起こることがある。他方，PINフォトダイオードは高感度ラドン検出器として開発され，スーパーカミオカンデにおいて使われてきている4。今回我々は，PINフォトダイ
オードを用いて，空気中のラドンを検出するラドン検出器を製作した。
PINフォトダイオードとして浜松ホトニクスの未封止S3204-09を使用した。空気容器としてステンレス
鍋，チャージ増幅器としてH4083，小型高圧電源モジュールとしてC4900-01，波形整形増幅器としてクリアパル
ス社の4419型，マルチチャンネルアナライザーとしてラボラトリーイクイップメント社のMCA-Lite，そして測定データ保存表示用にパソコンを使って，ラドン検出システムを製作した。マルチチャンネルアナライザーの出力は，鉱物ウラナイトからラドン娘核種の218Po and 214Poの明確なアルファ線ピークを検出した。このピーク
は大きなピークシフトを示したが，白いセラミックの表面をカーボンテープで覆うことで克服した。このシス
テムにシリカゲルで除湿した大気を導入したところ，同じラドン娘核種のピークを検出し，強度の日変化を観測することができた。
参考文献
1) G. Igarashi, T. Saeki, N. Takahata, Y. Sano, K. Sumikawa, S. Tasaka, Y. Sasaki, M. Takahashi:
Groundwater radon anomaly before the Kobe earthquake, Science, 269, 60-61, 1995
2) Yasuoka, Y. and Shinogi, M.: Anomaly in atmospheric radon concentration: a possible precursor of
the 1995 Kobe, Japan, earthquake. Health Physics, 72, 759-761, 1997
3) 長濱裕幸，安岡由美，鈴木俊幸，本間好：東北地方太平洋沖地震(MW=9.0)前の大気中ラドン濃度異常について. 日本地震学会講演予稿集, A32-09, 20114) 根本真知子，田坂茂樹，堀秀充，奥村公宏，梶原隆章，竹内康雄：静電捕集型超高感度空気中ラドン検出器の開発，RADIOISOTOPES, 46, 710-719, 1997.
キーワード：ラドン検出、大気、地震
Keywords: Radon detection, atmosphere, earthquake©2016. Japan Geoscience Union. All Right Reserved.

- MIS03-P03 -MIS03-P04

日本地球惑星科学連合2016年大会

Observational study of atmospheric electricity parameters(atmospheric electricity field(AEF), atmospheric ion concentration (AIC), and radon concentration) at Asahi, Boso
Peninsula, Japan
Observational study of atmospheric electricity parameters(atmospheric electricity field(AEF), atmospheric ion concentration (AIC), and radon concentration) at Asahi, Boso
Peninsula, Japan*大村 潤平1、Han Peng2、吉野 千恵2、服部 克巳2、下 道國3、小西 敏春4*Junpei Omura1, Peng Han2, Chie Yoshino2, Katsumi Hattori2, Michikuni Shimo3, Toshiharu Konishi4
1.千葉大学理学部地球科学科、2.千葉大学大学院理学研究科、3.藤田保健衛生大学、4.応用光研工業株式会社
1.Department of Science, Chiba Uiversity, 2.Graduate School of Science, Chiba University, 3.Fujita
Health University, 4.OHYO KOKEN KOGYO CO.,LTD.
The total electron content anomaly preceding the large earthquake is one of the most promisingprecursory phenomena in the upper atmosphere. Lithosphere–Atmosphere -Ionosphere coupling (LAI
coupling) model has been proposed to explain the earthquake-related phenomena in the atmosphere andionosphere. We evaluate the possibility of chemical channel of LAI coupling through the monitoringof atmospheric electricity parameters such as the atmospheric electricity field (AEF), atmospheric
ion concentration (AIC), and radon concentration. In this paper, we will report about the propertyof atmospheric electricity parameters observed at Asahi station (ASA), Boso Peninsula, Japan. AIC,
AEF, atmospheric radon concentration, radon exhalation quantity from the ground, and weather
elements have been observed at ASA. First, we compare seasonal variation, daily variation, andresponse to precipitation of atmospheric electric parameter observed at ASA and those at Kiyosumi
station (KYS).
Variations of AIC and AEF before precipitations are quite similar at both stations; AIC increases
quickly when a precipitation starts and AEF begins to be disturbed three hours before rain starts.
But the variations after stopping precipitation have individual properties. Both parameters keephigh values for a few hours at ASA and it takes longer than KYS to back to the normal level. Daily
variation in each season also differs in each site. In summer, AIC takes minimum value at 15:00 LT.
in the daily variation at ASA. But at KYS, it takes maximum value at 15:00 LT. In winter, AEF
decreases from 09:00 LT to noon and gradually increases in daily variation. In other seasons, ittakes maximum value at 20:00 LT and fluctuated in relatively large range. Daily variation of AEF in
winter is mostly similar to the typical daily variation at KYS for all season.
Radon exhalation quantity variation has a clear negative correlation with 3 hours delay to the airpressure variation. Each season differs in daily pattern. AIC and AEF variations show lag
correlation with radon exhalation quantity variation. To extract anomalous radon variation related
to earthquakes, we should set a network of Radon monitoring and establish a model of radon
variation for the future detailed analysis.
キーワード：Lithosphere–Atmosphere -Ionosphere coupling、atmospheric ion concentration、atmosphericelectricity field、 Radon exhalation quantity
Keywords: Lithosphere–Atmosphere -Ionosphere coupling, atmospheric ion concentration, atmosphericelectricity field, Radon exhalation quantity©2016. Japan Geoscience Union. All Right Reserved.

- MIS03-P04 -MIS03-P05

日本地球惑星科学連合2016年大会

Multi-parameter satellite geochemistry for validation of atmospheric pre-earthquake
signals associated with major seismicity. Case study for Xinjiang, China and Baja,
California*Dimitar Ouzounov1, Yeju Cui1,2, Nikolaos Hatzopoulos1
1.Center of Excellence in Earth Systems Modeling & Observations (CEESMO) , Schmid College of
Science & Technology Chapman University, Orange, California, USA, 2.Institute of Earthquake
Science, China Earthquake Administration, Beijing, China
We are presenting the development of satellite geochemistry for multi-sensor validation ofshort-term atmospheric phenomena preceding major earthquakes. The purpose of this study is to
explore the synergetic physical link between (1) satellite thermal infrared radiation (STIR) withanomalous distribution main trace gases :(2) Carbon dioxide (TCCO2), (3) Ozone (TCO3), (4) Methane(TCCH4) and (5) carbon monoxide (TCCO), associated with major seismicity. The science rationale formultidisciplinary analysis is based on concept Lithosphere-Atmosphere-Ionosphere Coupling (LAIC)(Pulinets and Ouzounov, 2011), which is based on the gas emission from the lithosphere during theearthquake generation and explains the synergy of different processes and anomalous variations,
usually named short-term pre-earthquake anomalies. We analyzed retrospectively several major
earthquakes in two deferent seismo-tectonic regions: XinJiang province in China and in Baja,
California including M7.2 of March 20, 2008 in China and M7.3 of April10, 2010 in Baja bysystematically analyzing multi-sensor satellite atmospheric chemistry and ground temperature/humidity observations. Meteorological satellite data include NOAA POES and AQUA/AIRS polar orbit
satellites. In both cases satellite data shows (STIR, TCCO2, TCO3, TCCH4, TCCO) building
atmospheric anomalies 1-20 days before the main shock. This probably is connected with enhances ofthe degassing rate of the lithosphere, which can provide additional source for flux emission near
major faults in the area. The hourly in-situ atmospheric observation show similarly in the airtemperature increases and drop in the relative humidity, probably as result of additional
atmospheric ionization observed before the three earthquake events. Our initial results suggestthat systematic use of multi-parameter satellite geochemistry can be used for additional physicalvalidation of pre-seismic processes associated with the major earthquake events.
Keywords: earthquake precursor, forecasting, satelite, geochemistry, radon©2016. Japan Geoscience Union. All Right Reserved.

- MIS03-P05 -MIS03-P06

日本地球惑星科学連合2016年大会

A statistical investigation of z test on seismo-ionospheric anomalies in TEC associatedearthquakes in Japan during 1999-2014*AiLing Shih1, Jann-Yenq Liu1
1.National Central University
Statistical analysis on seismo-ionospheric precursors (SIP) by using global ionosphere map (GIM) of
the total electron content (TEC) in associated with 188 M≥6.0 earthquakes in Japan during
1999-2014. Various references days of -15, ±7, ±15, ±30 days to the earthquake are employed to findcharacteristics of SIP. Results show that both decrease (or negative) and increase (or positive)
anomalies in the GIM TEC before the earthquakes are further examined by z test. The receiver
operating characteristic curve is also applied to see whether the SIPs exist in Japan.
Keywords: earthquake, ionosphere©2016. Japan Geoscience Union. All Right Reserved.

- MIS03-P06 -MIS03-P07

日本地球惑星科学連合2016年大会

3D Structure of Ionospheric Disturbances Related to Large Earthquakes
3D Structure of Ionospheric Disturbances Related to Large Earthquakes*Yagmur Mustafa1、Hirooka Shinji1、Hattori Katsumi1*Mustafa Yagmur1, Shinji Hirooka1, Katsumi Hattori1
1.Chiba University
1.Chiba University
In this paper we have investigated the geomagnetic storms and Earthquake-related ionosphericdisturbances. Following geomagnetic storms, the ionospheric peak electron density (Nmax) and total
electron content (TEC) often increase or decrease very much from their quiet-time levels. These
increase/decrease are known as positive and negative ionospheric storms. This paper deals with someextremely significant geomagnetic and Earthquake-related events in between 2000 and 2013 which
involving positive and negative ionospheric variations having immense importance to space weather,with reference to TEC maps derived from a dual-frequency GPS receiver network (GEONET: GPS Earth
Observation Network) built by the Geospatial Information Authority of Japan (GSI), as well as foF2
and hmF2 (maximum electron density height) derived from four ionosonde observatories in Japan and
GNSS-RO data from COSMIC mission of NOAA/NSPO(USA-Taiwan joint mission). For comparison anddiscrimination of stormy and large Earthquake days, a 3D Structure of Ionosphere will be discussed
in the presentation.
キーワード：Tomography、Ionospheric Disturbances、Geomagnetic Storms、Earthquakes、TEC
Keywords: Tomography, Ionospheric Disturbances, Geomagnetic Storms, Earthquakes, TEC©2016. Japan Geoscience Union. All Right Reserved.

- MIS03-P07 -MIS03-P08

日本地球惑星科学連合2016年大会

Assessment of Ionospheric TEC anomaly before large earthquake: Elimination of geomagnetic
storm effects*Katsumi Hattori1, Peng Han1, Shinji Hirooka1
1.Department of Earth Sciences, Graduate School of Science, Chiba University
The detection of electromagnetic perturbations prior to large earthquakes has been proposed as a
useful way to monitor the crustal activities. One of the most promising candidates is themeasurement of Total Electron Content (TEC). There have been many reports on TEC anomaly associatedwith large earthquakes from different parts of the world. To verify the relation between TEC
anomalies and seismicity around Japan, statistical studies by superposed epoch analysis have been
carried out. The results have indicated that before a M>6 earthquake there are clearly higher
probabilities of positive TEC anomalies in Japan. These results indicate the correlation between
TEC anomalies and sizeable earthquakes. Furthermore, by making use of long-term TEC data over Japan
during 2000-2013 and applying Molchan’s error diagram, we can evaluate the optimal parameter forearthquake forecasting. The results show that the TEC data contain potentially useful information
on earthquake forecasts.
Further research on earthquake forecasting and promoting its utilization will greatly contribute todisaster risk reduction. By using an interdisciplinary or integrated approach, which connects
science with technologies related to the ongoing earthquake forecast researches such as ULF
geomagnetic and GNSS methods, earthquake forecasting will be demonstratively realized.
Keywords: Ionospheric TEC anomaly, statistical studies, Molchan’s error diagram©2016. Japan Geoscience Union. All Right Reserved.

- MIS03-P08 -MIS03-P09

日本地球惑星科学連合2016年大会

Statistical Analysis on ULF magnetic anomaly and local seismicity around Kakioka, Japan*Rui Du1, Katsumi Hattori1, Peng Han1
1.Graduate School of Science, Chiba University
To clarify and verify the ultra-low frequency (ULF) seismo-magnetic phenomena, we have performed
statistical studies on the geomagnetic data observed at the Kakioka (KAK) station, Japan, during
2001-2010. We investigated the energy of ULF geomagnetic signals of the frequency around 0.01Hz
using wavelet transform analysis. To minimize the influences of artificial noises and global
geomagnetic perturbations, we used only the geomagnetic data observed at nighttime (LT 2:30 am-4:00
am) and exclude the geomagnetic anomalies when the energy of horizontal component is large.
Statistical results of superposed epoch analysis have indicated that ULF magnetic anomalies are
more likely to appear before sizeable earthquake events (Es>108) rather than after them, especially
6-10 days before the events.
Finally, we have evaluated the precursory information of ULF geomagnetic signals for local sizeable
earthquakes using Molchan’s error diagram. We also compared our results with previous statisticalstudies at KAK. The above results have indicated that the ULF seismo-magnetic phenomena at KAK
clearly contain precursory information and have a possibility of improving the forecasting of large
earthquakes.
Keywords: ULF seismo-magnetic phenomena, statistical study, superposed epoch analysis (SEA),
Molchan’s error diagram©2016. Japan Geoscience Union. All Right Reserved.

- MIS03-P09 -MIS03-P10

日本地球惑星科学連合2016年大会

地下水動態に起因した自然電位変動と自然電位トモグラフィー
The self-potential variation induced by groundwater flow and the self-potential tomography*山崎 智寛1、服部 克巳1、寺嶋 智巳2*Tomohiro Yamazaki1, Katsumi Hattori1, Tomomi Terajima2
1.千葉大学大学院理学研究科、2.京都大学防災研究所
1.Depart of Earth Sciences Faculty of Science , Chiba University, 2.Disaster Prevention ResearchInstitute, Kyoto University
Landslide is one of the most severe natural hazards in the world and there are two types;
rainfall-induced landslides and landslides triggered by an earthquake. To understand rainfallinduced landslide process by the self-potential approach, we struggle with the integrated research
to clarify the coupling among hydrological, geotechnical, and electromagnetic changes. Our final
goal is to develop a simple technology for landslide monitoring/forecasting using self-potential
method. The previous laboratory experiments show that the self-potential variation has arelationship with the ground water condition and soil displacements. So, in this paper, we first
demonstrate the numerical computations on the self-potential variation by the simulated groundwater
flow, and compare the result with those observed by laboratory experiments. In the result, thesimulated self-potential variation is consistent with observed one.
Then, we developed self-potential tomography to estimate the ground water condition. And we alsocharacterize the pressure from the self-potential data, and compare the result with observedpressure head that is measured by pore-pressure gauge and found that the inverted pressure head isconsistent with observed one. In addition, we apply the self-potential data observed by the flume
test. The estimated pressure head from observed self-potential data shows the consistency withobserved pressure head. And estimated pressure head also show the characteristic distribution
before the landslide occurred. These facts are highly suggestive in effectiveness of theself-potential tomography to monitor groundwater changes associated with landslide. The details
will be given in our presentation.
キーワード：自然電位、斜面崩壊、トモグラフィー
Keywords: Self-potential, Landslide, Tomography©2016. Japan Geoscience Union. All Right Reserved.

- MIS03-P10 -MIS03-P11

日本地球惑星科学連合2016年大会

A Mechanism Causing Temporal Variation in b-values Prior to a Mainshock*Jeen-Hwa Wang1
1.Academia Sinica
Observations exhibit the temporal variation in b-values prior to a mainshock. The b-value starts toincrease from the normal value at time t1, reaches its peak one at time t2, then begins to decrease
from the peak one at t2, and returns to the normal one at time t3. As t>t3, the b-value varies
around the normal one or rightly decreases with time until the occurrence of the forthcoming
mainshock at time t4. The precursor time, T=t4-t1, of b-value anomalies prior to a forthcoming
mainshock is related to the magnitude, M, of the event in a form: log(T)=q+rM (T usually in days)
where q and r are two constants. In this study, the mechanism causing b-value anomalies prior to amainshock is explored. From numerical simulations based on the 1-D dynamical spring-slider mode
proposed by Burridge and Knopoff (1967), Wang (1995) found a power-law correlation between b and s,
where the parameter s is the ratio of the spring constant (K) between two sliders to that (L)between a slider and the moving plate. The power-law correlation are b~s-2/3 for the cumulative
frequency and b~s-1/2 for the discrete frequency. Since L of a source area is almost constant for along time period, b directly relates to K. Lower K results in a higher b-value. Wang (2012) found
K=rAvp2, where rA and vp are, respectively, the areal density and P-wave velocity of a fault zone.
Experimental results show that vp is strongly influenced by the water saturation in rocks. The
water saturation in the source area varies with time, thus leading to a temporal variation in vp aswell as K. This results in the temporal variation in b-values prior to a mainshock. The modeled
result is consistent with the observed one.
Keywords: b-value, precursor time, spring-slider model, stiffmess ratio, saturation of water©2016. Japan Geoscience Union. All Right Reserved.

- MIS03-P11 -MIS03-P12

日本地球惑星科学連合2016年大会

b値を用いた応力場変動予測と地震活動総合予測の試み
Integrated earthquake forecast: combination of b-value monitoring and ionosphericprecursors*小張 剛照1、韓 鵬1、服部 克巳1*takaaki Kobari1, Pen Han1, Kastumi Hattori1
1.千葉大学大学院理学研究科
1.Department of Earth Sciences, Graduate School of Science, Chiba University
近年、地震活動に先行する様々な電磁気現象が報告されており、その中でも電離圏総電子数(Total Electron
content: TEC)の異常は、短期地震予測の有力な候補として知られている(1)。
一方、地圏では大地震に先行してグーテンベルク・リヒター則に従うｂ値が本震付近において本震の数年前(場合によって数十年スケール)から低下する現象が報告されている(2)。そこで本報告ではb値解析によって中期的に規模の大きな地震発生予測を行ってから、詳細な電磁気解析を行うスキームの有効性について、十勝沖をテストサイトとして調査した。本稿では2003年9月11日（Mj8.0）と2008年9月26日に発生した十勝沖地震(Mj7.1)を対象とし、地圏での応力場の変動(b値)と電離圏総電子数(GIM-TEC、GPS-TEC)の変動の調査結果をそれぞれ報告する。さらに、上記の事例研究をもとに地圏での応力場の時空間的変動をprospectiveな視点で千葉県房総周辺、南海トラフ、千島海溝を調査した結果について報告する。
キーワード：地震、電磁気、b値、電離層
Keywords: Earthquake, Electromagnetic, b-value, Ionosphere©2016. Japan Geoscience Union. All Right Reserved.

- MIS03-P12 -MIS03-P13

日本地球惑星科学連合2016年大会

Development of the quasi-real-time monitoring of volcanic lava activity using MODIS
Development of the quasi-real-time monitoring of volcanic lava activity using MODIS*安 ビョンジン1、服部 克巳2、Nicola Genzano3*BYOUNGJIN AHN1, Katsumi Hattori2, Nicola Genzano3
1.千葉大学理学部地球科学科、2.千葉大学大学院理学研究科、3.University of Basilicata
1.Department of science, Faculty of Science, Chiba University, 2.Department of Earth Sciences,
Graduate School of Science, Chiba University, 3.University of Basilicata
It is possible to quasi-realtime monitoring of volcanic lava activity could be possible if we candetect the thermal anomalies related to the exposure and lava dome of magma by satellite sensors
such as MODIS. And it can be used to help for the volcano disaster prevention. In this study, wedeal with seven volcanoes in Indonesia. First, we define the infrared radiation caused by theeruption and then, we use the statistical analysis for the radiation, and remove the cloud effects.
Finally, we investigate the abnormal values against the background level of the temperature.
We introduce an evaluation function S to remove the spatial and temporal variation from thespatial difference of the brightness temperature data between the target point and reference point(5 km distance). When we compute the differences, we need to eliminate cloud effects adequately. To
achieve this, we use the brightness temperature difference between bands of MODIS (BTD). In thisstudy, we select the following combinations ; (1) Band34-Band35 (BTD(t)-μ < kσ, k=-2.0:), (2)Band31-Band27 ( BTD(t)-μ < kσ, k=-2.6), (3) Band31-Band32 (|BTD(t)-μ| < kσ, k=-3.0), and (4)Band20-Band31 (|BTD(t)-μ| < kσ, k=-3.0). Where t, k, m, and s are the season, threshold for cloud
identification, average, standard deviation for each distribution of BTD. Until the distribution
satisfy the equation, we repeat the test. Then, we move to the next test. We perform this procedure
up to test 4. Then we get the pixels without cloud. The result is evaluated using LIDAR data
onboard CALIPSO, which has the almost same orbit and constellated with AQUA. After removing thecloud effect, we compute the deviation rate d. As results for 15 years data analysis for 7
volcanoes in Indonesia, when the deviation rate exceeds in target volcanoes 6σ, there is a tendency
to have a lava volcanic activities. However, without removing the cloud effects, we find it isdifficult to identify the anomaly related to the lava activities. Therefore, it is highlysuggestive of the proposed method is valid for monitoring volcanoes and volcanic risk reduction.
キーワード：MODIS、火山、リモートセンシング
Keywords: MODIS, Volcano, Remote Sensing©2016. Japan Geoscience Union. All Right Reserved.

- MIS03-P13 -MIS03-P14

日本地球惑星科学連合2016年大会

房総半島を対象としたMT探査と予察的考察 (2)MT survey and its preliminary result at Boso Peninsula, Japan (2)*小泉 直輝1、陳 浩1、韓 鵬1、吉野 千恵1、服部 克巳1、奥田 真央2、菅野 倖太朗2、早川 美土里2、茂木 透2、坂中 伸也3*Naoki Koizumi1, Hao Cheng1, Peng Han1, Chie Yoshino1, Katsumi Hattori1, Mao Okuda2, Kotaro Sugano2,
Midori Hayakawa2, Toru Mogi2, Shin'ya Sakanaka3
1.千葉大学大学院理学研究科、2.北海道大学大学院理学院、3.秋田大学大学院工学資源学研究科地球資源学専
攻
1.Graduate School of Science, Chiba University, 2.Graduate School of Science, Hokkaido University,
3.Department of Earth Science and Technology, Graduate school of Engineering and Resource Science,
Akita University
A magnetotelluric (MT) survey is one of the methods to understand the underground electric
properties. In Boso area, Japan, there are three main topic to perform the MT survey; (1) toestimate underground resistivity structures related to the plate boundaries, seamount, asperities,
and slow slip events; (2) to obtain a regional realistic resistivity structure for the numericalsimulation in generation and propagation mechanisms of electromagnetic precursors, and (3) todevelop a new MT technique to reduce the cultivated noises such as DC-driven train system andfactories. For challenges to solve them, we decided to carry out the MT survey in Boso area, Japan
during 2014-2016. Due to sensing down to 100 km depth, we used induction and fluxgate
magnetometers. We set 41 and 12 sites for induction and fluxgate type magnetometers, respectively.
The preliminary 1-D inversion results for 41 induction sites show that we can presume apparent
resistivity about 1 km - 10 km depth from the surface, but relatively not clear about 100 m - 1 km
and 10 km - 100 km depth from the surface. In addition, we found that the noises tend to be weakerin the southern region compared to the northern region.
To presume resistivity structure in Boso Peninsula, it is necessary to remove the artificial
noises from observed MT data. The observed noises have characteristics of transient signals andprocesses in time domain are required such as singular spectrum analysis. Moreover, twe will
analyze the observed data of 12 stations in which we used fluxgate type magnetometer to obtainlower frequency and deeper information.
キーワード：MT法、房総半島
Keywords: MT method, Boso Peninsula©2016. Japan Geoscience Union. All Right Reserved.

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