SSS25-01

Room:301B

Time:May 20 15:30-15:45

Precursor observed by movements of aero-ionization measurement prior to the pacificcoast of tohoku earthquake in 2011
YADA, Naoyuki1∗ , SAITO, Yoshiharu2
1

Kanagawa Institute of Technology, 2 e-PISCO

1. Introduction
Earthquake predictions that predict when, where, how much of an earthquake will happen, is one of the most important theme
in Japan. In this study, we aim at correct information of earthquake predictions by means of measurements for aero-ionizationin many measurement points. Before the 3.11 earthquake, in our network of measurement an unusual behavior appeared. This
study reported the unusual behavior in detail.
2. Experimental method
The experimental apparatus is based on Gerdien-condensor method, was developed by COMSYSTEM Co.Ltd. The apparatus
has been setting up in a campus of Kanagawa Institute of Technology(KAIT), and aero-ionization value have been measured in
24 hours. The data of ionization was sent to the headquarters of e-PISCO and was opened in a website. In KAIT we havemeasured aero-ionization since ten years ago, predictions of earthquake have been informed locally. The target earthquakes ofpredictions were sensible earthquakes in Kanagawa Pref. or over the magnitude 5.0.
3. Results and discussions
This study reports the unusual behaviors of aero-ionization measurements in some experimental points in December 2010
before the 3.11 earthquake. Especially the unusual behavior appeared at Matsumoto measurements point in Nagano Pref., which
is located over 500 km from the epicenter. The unusual behavior is wondered that the experimental apparatus is in trouble.
In our experience, for one large earthquake(M=7.0) cause less than 5 times of unusual behavior for aero-ionization, based on
this experience we succeed in predictions for the day of Chuetsu earthquake in 2004 and of Iwate-Miyagi earthquake in 2008 andso on. On the contrary, for the 3.11 earthquake both behavior and period of aero-ionization have the new case, and we cannot
predict the earthquake.
4. Conclusions
Now, for correct information of earthquake predictions, many method have been challenged. The method of aero-ionization
observation is one of them. Because all of them have some demerits each other, in the present a better way is combination ofsome methods. Although for the prediction of earthquakes, many discussions occurred academically, many challenges should
be executed by means of various methods.

Keywords: prediction of earthquake, precursor, aero-ionization, the pacific coast of tohoku eartquake in 2011

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SSS25-02

Room:301B

Time:May 20 15:45-16:00

Precursory and after-effect anomalous groundwater changes associated with the 2011 giant Tohoku earthquake of M9.0
TSUKUDA, Tameshige1∗
1Japan Woomen’s University

Clear precursory changes for the 2011 off the Pacific coast of Tohoku Earthquakethe of M9.0 was recorded in electric conductivity and temperature of groundwater, representing the changes on ion concentration and water temperature induced by the
intrusion of water from deep underground, which is responsible to the crustal stress conditions. The observing point, Deyu Hot
Spring, Agano City, Niigata Prefecture, is located 200km west of the end of the seismic fault of the earthqake. Since April, 2001,
Mr. Sadao Kawakami has been manually measuring temperature and electric conductivity of groundwater at the hot spring. The
measurement is conducted at an interval of one week for the water pumped up from the well. Furthermore, we have temperature
data recorded automatically since December 7, 2008. Around the end of 2009 the conductivity started to decrease with clearlydecreasing temperature, indicating stress relaxation underground. Then the conductivity tended to increase in May, 2010, andthe temperature similarly turned to increase in December, the same year. The resultantl precursory time is one year and several
months. The conductivity data from this observation station had recorded precursors before the 2004 Niigata Chuetsu Earthquakeof M6.8 and the 2007 Niigata Chuetsu-oki Earthquake of M6.8. Clear after-effect groundwater temperature rises were recordedat Nuruyu Hot Spring, Awaji City, Hyogo Pref., and Ushio Hot Spring, Unnan City, Shimane Pref. The rise time and hight are 20
days and 70m degree in centigrade at Nuruyu, and 10 hours and several hours and 3.5 degree at Ushio, respectively.
Keywords: groundwater, ground water temperature, electric conductivity, earthquake prediction, precursor, after-effect

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SSS25-03

Room:301B

Time:May 20 16:00-16:15

Re-examination of seismic quiescence prior to the 2011 Tohoku earthquake
YOSHIKAWA, Sumio1∗ , Naoki Hayashimoto2
1

Magnetic Observatory of JMA, 2 Meteorological Research InstituteWe have presented the seismic quiescence to be detected prior to the 2011 Tohoku earthquake in the last SSJ meeting(Yoshikawa,2011). We examined two cases of the periods, considering the difference of the detectability of seismic activity.
According to this, the seismic quiescence appeared since 2001 around the San-Riku coastal area, the major length of three to four
hundred km, in the period from October 1997 to February 2011 with the threshold of M3.0 (Case-A). And it appeared since 1996
in the wider area than the above case with the major length 500 km, in the period from January 1984 to February 2011 with thethreshold of M4.0 (Case-B). Against this result, it was pointed out that the appearance should be influenced by de-clustering andthe seismic activity in the reference period. And as stated above, the difference of the quiescence area and the period between thetwo cases suggests dependences of the parameters used for the analysis of the quiescence. In this study we present the results ofre-examination, considering the problems.
As a method for detection of seismic quiescence we chose the method developed by Aketagawa and Ito (2008) and Hayashimotoand Aketagawa (2010) in order to find the areas of activation and quiescence of seismicity (hereafter, it may be called ’e-Map’).
We can obtain the seismicity map depending on the seismic density of each region by this method. We investigated the influencesof the threshold of magnitude, the radius of the test circle in survey area, the reference period, the survey period, etc. and foundthat the appearance form of quiescence area can be remarkably changed by choice of the above parameters, although a scaling
law between the quiescence area and the magnitude of the earthquakes accompanied by seismic quiescence was clear.
As the results of the study, we did not find large differences both in the area and commencement of quiescence prior to the2011 Tohoku earthquake caused by de-clustering. And we found that since the seismic activity in the coastal area of the San-Riku
became high from 1989 to 1995, it makes the appearance of quiescence earlier, if the reference period includes that active period.
Then as we set the reference period in the period from 1984 to 1988 for Case-B, the appearance of quiescence delayed to 2001,
as in Case-A.

Keywords: seismic activity, quiescence, Tohoku earthquake

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SSS25-04

Room:301B

Time:May 20 16:15-16:30

Groundwater level changes associated with aftershocks following the 2011 M7 earthquake occurred in Iwaki City, JapanOTSUKI, Kenshiro1∗
1

Dept. of Geol., Grad. S. of Sci., Tohoku Univ.

The great Tohoku-oki earthquake induced a normal fault-type M7 earthquake beneath the western part of Iwaki City on April
11, 2011. A NNW-SSE trending surface rupture longer than ten kilometers emerged with west side throw as large as 2 m. It
is an opportunity to observe ground water level (GWL) changes associated with many aftershocks within a short observation
period. The observation at a short epicentral distance also is advantageous to detecting precursory changes. Borrowing two deep
boreholes in the aftershock area, I conducted GWL observation during 50 days since April 21. Borehole SMK is located 4.3 km
southeast from the southern tip of the surface rupture, and borehole HLN is 6.2 km east from SMK. The precision of water-level
gauges used is 1 mm, and the data were acquired minutely. The GWL changes related to 23 inland shallow aftershocks and 4
deeper earthquakes off Iwaki City were recorded.
1) GWL rose about 4 m at SMK, while about 5 m dropped at HLN. These changes are approximated well by exponentialfunctions of time whose origins are set at April 11. They indicate that the GWL at SMK (HLN) dropped (rose) about 8 m (10 m)
just after the earthquake and rose (dropped) thereafter at a relaxation time of 47.6 days (29.4 days).
2) The effects of the earth tide and barometric pressure to GWL were corrected by using BAYTAP-G. Comparing the output
components attributed to the earth tide with the corresponding volumetric strain calculated by GOTIC-2, 1 mm GWL change at
SMK and HLN are estimated to be equivalent to the volumetric strain of 0.30 and 0.24 nano-strain, respectively.
3) After defining the normalized earthquake magnitude M∗ as M∗ = M - Mc and the lower limit magnitude Mc below
which earthquakes are not detected as GWL changes as Mc = 2.4logr ? 1.0, 156 earthquakes which fulfill the condition M∗>1
were selected from JMA database. The parameter r denotes the epicentral distance (in km). The occurrence of the earthquakes
with larger M∗ are synchronous with step-like GWL changes which are found in the trend-component output from BYTAP-G.
Obviously the lager M∗, the higher step. Through such procedure 27 and 10 earthquakes-related GWL changes were identified
in the data from SMK and HLN, respectively. The maximum change attains 52 mm.
4) Mc is expressed conclusively as Mc = 2.48logr ? 1.00 for the data from SMK. The relation between the observed GWLchanges w (mm) and M∗ are approximated as M∗ = 0.704logw ? 0.198, being consistent with a theoretical consideration.
5) Focal mechanism solutions of the 24 earthquakes among the 27 earthquakes are opened on the websites of JMA or NIED.
Using the source parameters and MICAP-G, static volumetric strain changes at SMK and HLN were calculated. They were converted to GWL changes and compared with the observed values. As a result, they are consistent each other for 15 earthquakes (63%). When the epicentral positions are allowed to move slightly within their determination errors, the theoretical GWL changes
can be consistent with the observed values for the additional 7 earthquakes (29 %). With regard to the data for 92 % of theearthquakes, the ratios of volumetric strain to GWL change are averaged to 0.38 nano-strain/mm for the data from SMK, being
consistent with the volumetric strain equivalent to water level change (0.30 nano-strain/mm). These results strongly suggest thatthe main cause of the GWL changes is the static volumetric strain changes. The GWL changes related to other two earthquakes
may be due to ground shaking.
6) It is not rare that small (<several mm) GWL changes preceded a few hours before earthquakes (11 among 37 observations). These preseismic changes may be attributed to the incomplete correction of the effects of the earth tide, but the preliminary
examination rejected this possibility. Evidences which indicate the preseismic changes as precursors have not been obtained so
far.

Keywords: groundwater level, Iwaki earthquake, aftershocks, volumetric strain, precursor

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SSS25-05

Room:301B

Time:May 20 16:30-16:45

Characteristics of Date, Time and Lunar Phase of Giant Earthquakes for Each Subduction
Zone
OZAKI, Yuki1∗ , FUJII, Yoshiaki1
1

Hokkaido University

There are several studies which suggest that the tidal force affects earthquake occurrence. The studies focus on earthquake
precursory of Sumatra (Tanaka, 2010), non-volcanic tremor resulting from slow slip events (Nakata et al., 2008) etc. If predictions
on date, lunar phase and time of giant earthquake occurrences can be narrowed for every subduction zone, it would be very
effective to reduce earthquake damages. Only the giant main shock, mainly Mw 8+ earthquakes between 1900 and 2011, were
investigated for each subduction zone in this study. UTC is used hereafter.
In Kuril Islands, six of the seven earthquakes occurred during Aug. 11 and Nov. 15 on lunar phase between 24.2 and 1.6 days.
Earthquakes of Hokkaido in Japan near Kuril Islands occurred in a similar manner. In Tonga, four of the five earthquakes occurred
during Apr. 30 to June 26. All events occurred on lunar phase between 0.8 and 6.2 days and between 5:07 and 15:26. In Chile, noclear date dependency is observed. However, four of the seven earthquakes occurred around the new moon (lunar phase between
22.1 and 1.8 days) and two occurred just before the full moon (lunar phase between 12.0 and 13.6 days). All events occurred
during 16:07 to 6:34. In Peru, no clear date dependency is observed. However, three of the seven earthquakes occurred aroundthe new moon (lunar phase between 2.2 and 3.5 days) and the rest four occurred around the full moon (lunar phase between 12.6
and 18.8 days). All events occurred during 12:08 and 23:40. In Japan, three of the six giant earthquakes occurred around thelunar phase of 6 days and the rest three occurred around the lunar phase of 20 days. Five of the six earthquakes occurred during
Mar. 2 to June 15. No clear dependency was observed for earthquakes in Southeast Asia.

M JM A 6+ earthquakes in Japan were investigated since there are not enough Mw 8+ earthquakes. No clear dependency
between the earthquake occurrence and lunar phase was observed. However, in the case of M JM A 7+ earthquake occurrence ishigh on lunar phase between 6 and 12 days and between 20 and 22 days. All land earthquakes occurred on lunar phase between
4 and 14 days and between 20 and 22 days.
Investigating the areas (Hokkaido, Pacific Ocean side between Aomori and Chiba, Kansai, Kyushu and Okinawa islands), theearthquakes in Hokkaido were similar to the ones in Kuril Islands. Giant earthquakes occurred on lunar phase between 20 and 0days. Most earthquakes in Pacific Ocean along Aomori to Chiba occurred on lunar phase of about 6, 12 and 22 days. The mostearthquakes in western part of Japan were on lunar phase between 9 and 21 days. Not many giant earthquakes in this area.
Investigating the seasons, most earthquakes in February to April occurred on lunar phase between 4 and 15 days. Earthquakes
which occurred in May to July occurred on lunar phase between 10 and 20 days. Most giant earthquakes in August to January
occurred on lunar phase between 20 and 0 days. Occurrence of the giant earthquakes was higher during winter to spring thansummer to fall.
If a dangerous time zone is narrowed for each subduction zone in future, the validity will be examined based on change inthe stress state of the subduction zone by tidal force. Investigation on the stress state of the whole subduction zone rather thanstatistical analysis for small earthquakes will be carried out since the prediction of giant main shocks is much more important
than that of predict small earthquakes.

Keywords: giant earthquake, lunar phase, tidal force, subduction zone, plate

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SSS25-05

Room:301B

Time:May 20 16:30-16:45

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SSS25-06

Room:301B

Time:May 20 16:45-17:00

Long-term probability forecast of the regional seismicity that was induced by the M9
Tohoku-Oki earthquake
OGATA, Yosihiko1∗
1

The Institute of Statistical Mathematics

Seismicity of the eastern Japan has become active, induced by the M9 Tohoku-Oki earthquake of 11 March 2011. Since
November 2009, Japan Testing Center of the CSEP has been evaluating some probabilistic forecasts of seismic activity in andaround the Japanese islands, including the Kanto region and inland areas. However, it now accepts re-submissions of the probability forecasts due to the influence of this M9 mega-earthquake. Originally, these were relatively short-term forecasts that assumes
the space-time probability forecasts. However, recently, long- and mid-term forecast of probability of large earthquakes in theTokyo metropolitan area has been attracting wide attention.
In this report, I will consider such a forecasting method for each region of Japan. If the region does not contain the M9 earthquake in it, I predict the seismicity rate by the superposed model of the ETAS model and the Omori-Utsu formula. Here, theETAS model represents the triggered earthquake chains within the region, and the Omori-Utsu formula represents the induced
seismic activity by the M9 earthquake. This superposed model fit well to data for period up until now. Hence, I will use this toforecast of seismic activity of the region in the future.
A sequence of earthquake magnitudes may be generated by use of the Gutenberg-Richter’s law. However, this is not quite suitable for an unbiased prediction of frequency of large earthquakes because the b-value can be different depending on the threshold
magnitude. Alternatively, I will simulate them by bootstrap re-sampling based on the magnitude data of the earthquakes in that
region of the Utsu catalog (1885-1925) and the JMA catalog before and after the unification (November 1997). Here, the resampling weights considering the detection rate and duration of each catalog.
After obtained the magnitude series of earthquakes, I simulate the seismic activity using the superposed model of the ETAS
and Omori-Utsu formula. Repeating this procedure, we estimate long-term probability of occurrence of large earthquakes. In thisreport, we will see probabilities of large earthquakes during the passage of up to 30 years period in South Kanto metropolitanarea, the Tohoku inland region and the Itoigawa-Shizuoka Tectonic zone

Keywords: long-term probability forecast, ETAS model, Omori-Utsu formula, Bootstrap resampling

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SSS25-P01

Room:Convention Hall

Time:May 20 17:15-18:30

On the sea level changes that were witnessed before the 1946 Nankai earthquake on the
Pacific coast of Shikoku, Japan
UMEDA, Yasuhiro1∗ , ITABA Satoshi1
1GSJ, AIST

There are a lot of witness testimonies on abnormal sea level changes just before the 1946 Nankai earthquake on the Pacificcoast of Shikoku, Japan.
Keywords: 1946 Nankai earthquake, witness testimony, sea level change

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SSS25-P02

Room:Convention Hall

Time:May 20 17:15-18:30

Laborsaving using the database system in a Manten project
BAN, Yasunori1∗ , Masayo Sawada1 , Tsutomu Miura1 , Itaru Yoneda1 , Hiroshi KATAO1 , Yoshihisa Iio1
1

RCEP, DPRI, Kyoto Univ.
We report that improvement of Manten database system reported by Sawada,2009. The improving point is below.
1. The input-output method has been imporved in accordance with business.
2. Speed up of observation point maintenance report
The improving point 1 is shown below.
i.Correction and deletion of incorrect input data were enable.
ii.Search of the information of a sensor and logger is made easy.
iii.Unified for program
The improving point 2 is show below.
i.We enabled to input a maintenance report from web.
ii.We enabled to reflect in a database web.
iii.Security is raised.

Keywords: Manten Project, Data Base, Laborsaving

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SSS25-P03

Room:Convention Hall

Time:May 20 17:15-18:30

A study on the time interval of Dashed-Line-Noise.
TAKAHASHI, Fuminori1∗1

None

Dashed-Line-Noise(DLN) is a noise like dotted lines which appear in the analog television image of VHF band. It meansthat the interval of DLN is calculable by the algebraic geometry. In the 2010’s JpGU, I introduced a method of calculating theinterval using two directional vectors, and then I presented the fact that there is a strange thing in the interval. It is that the intervalsometimes changes a lot, without changing the angle of a dashed line. In order to explain this phenomenon briefly, I advocatedthe model in which some two phenomena are participating for generating of DLN. One is the phenomenon of changing angle
continuously and the other is the phenomenon of changing the interval discontinuously.
In this meeting, I will show the calibrated data using the horizontal synchronization of analog broadcasting, and present thefact that the interval is really discrete.

Keywords: Dashed Line Noise, short term earthquake prediction, macroanomaly

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SSS25-P04

Room:Convention Hall

Time:May 20 17:15-18:30

Fundamental measurements of Radon concentration in a cave and the atmosphere forearthquake prediction
NINAGAWA, Kiyotaka1∗ , UCHIKAWA, Takahiro1 , YAMAMOTO, Isao2 , KAWANO, Shigenori3 , OKABAYASHI, Tohru4
1

Department of Applied Physics, Okayama University of Science, 2 Department of Information and Computer Engineering,
Okayama University of Science, 3 The Shimane Nature Museum of Mt. Sanbe, 4 Department of Medical Risk and Crisis Management, Chiba Institute of Science
An increase of the radon in underground water at Nishinomiya City1 and an increase of the radon in atmosphere2 at thesouthern part of Hyogo Prefecture earthquake in 1995 were reported. Moreover, in the case of Tohoku Region Pacific Coast
Earthquake, the data of the exhaust air monitor in the radiation facility of Fukushima Medical College (Fukushima) has beenreported that the peak duration was long, and the peak decreased rapidly before the earthquake3 .
We had started to measure radon concentration in the cave in Kurashiki, Okayama from the beginning of November, 2009,and started to measure radon concentration in the atmosphere from the end of May, 2011 in Choshi, Chiba. We used a RadonMonitor of SUN NUCLEAR Corporation, Model 1028 in the Kurashiki, and a Pylon Trace Environmental Level Radon Gas
Detector in Choshi.
In the cave in Kurashiki, there is a tendency that radon concentration goes up after rainfall. Moreover, radon concentration
becomes high in May and June, and in September and October as the seasonal variation. Earthquakes hardly occur in Okayama
Prefecture. An earthquake(M=5.4) at 19:16 on November 21, 2011, northern Hiroshima (N34.9o , E132.9o , depth:12km, Distance: 90km) occurred. The radon concentration increased before the earthquake. However, there is rainfall before the day ofradon increase. Then we could not get clear correlation between radon increase and the earthquake.
The radon concentration in the atmosphere of Choshi has a tendency of increase from September to winter. However, one year
has not passed since the measurement start. Whether this increase means the usual seasonal variation or not is not clear. There
are many aftershocks near Choshi. It is difficult to search for correlation between radon concentration variation and earthquakes.
Since the data of Kobe Pharmaceutical University and Fukushima Medical University are a prolonged measurement over ten
years, it is necessary to continue radon concentration measurement for a long period in Kurashiki and Choshi.
References
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) Nagahama H., Yasuoka Y., Suzuki T., and Homma Y.: Radon Variation in the Air Before the 2011 Tohoku Earthquake (Mw=9.0), Programme and Abstracts, A32-09, The Seismological Society of Japan. 2011, Fall Meeting.

Keywords: radon, cave, atmosphere, earthquake, prediction

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SSS25-P05

Room:Convention Hall

Time:May 20 17:15-18:30

Numerical analysis of catfish movement at different location, concerning the possibilityof earthquake foretelling
FUJII, Mao1∗ , YADA, Naoyuki2
1

Secondary school attached to the Faculty of Education of the University of Tokyo, 2 Kanagawa Institute of Technology
Numerical analysis of catfish movement at different location, concerning the possibility of earthquake foretelling

1. Outline
It has been reported several times that some kind of animals act unusually before big earthquakes. Besides, the 3.11(2011)
Earthquake in Japan encouraged civil studies toward General natural unusualness observation and Abnormal animal movement.
However, official case studies of constantly monitoring animals for earthquake foretelling challenge have been quite rare. In
this report, we observed two catfishes (Japanese and South American) located in different places (Kanagawa and Tokyo), which
is often referred to doing unusual action before big earthquakes. First objective is to compare two catfish movement at different
places, secondly, to compare the movement with actual earthquakes on the viewpoint of magnitude and seismic center.
2. Keeping and observation of catfish
Species: [Tokyo] Tiger shovel nose cat (South American)[Kanagawa] Japanese catfish
Condition: 60cm glass tank, GEX∗ Dual Clean upper filtering system
Monitoring: one Keyence∗ infrared counter near the top of tank1) Observation
Recorded every 24hr. moving counts by resetting the infrared counter once a day.
This has been continued since July 2011.
2) Overall trend
A catfish’s habit is rather benthos, and it seldom moves. Normally, the counter value per day is around 20 - 30. However,sometimes a catfish moves in a different manner, and the counter value exceeds 100 or 200. Thus, the unusual action of catfish isclearly distinguished from the usual one.
Some positive correlation between this unusual action and actual earthquakes could be found. The degree of correlation
depends on the settings of magnitude range and location range of epicenters. Further studies should be required on these pointsof view.

3) Keeping a catfish
Keeping a catfish requires general water state control (commonly with tropical fish) and feeding just once a day. These facts
are bright factors to build a future catfish observation network.

3. Results
The results of catfish observation since July 2011 are as follows.
- Positive correlation of 2 catfish of Kanagawa and Tokyo(Especially August 2011, there was clearly high correlation.)- Positive correlation with actual earthquakes(Especially epicenter location of Chiba, Ibaraki area )Further desirable studies;
1) Larger number of catfish in different area
2) More analysis of correlated earthquakes
Keywords: earthquake foretelling, catfish, abnormal animal action, sign of earthquake, multiple point observation

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SSS25-P06

Room:Convention Hall

Time:May 20 17:15-18:30

Anomalous electric fields before 2011 Far E off Miyagi Pref. EQ
TAKAHASHI, Kozo1∗ , Igor Matveev2
1

Formerly CRL, 2 IPE RAS

Introduction: To develop a method for earthquake prediction, electric fields are being observed, and the fields before and after
the EQ of M9.0 occurred on 2011/03/11 were observed. But the observation had the problems as follows:(1) The data for one month before the EQ were lacking.
The instrument erases the recorded data when the power comes back on after power failure. The power was cut off by theEQ, and we could not arrive on the observation site before the power came back on.
(2) The observed data are recorded every two minutes, but it is doubtful whether the data at four sites were synchronized ornot, as the clock is not accurate.
In our observing area, except special bands, man-made noise is not simultaneously observed at the sites which are separated
about 100km apart, so we regard the pulses as precursory ones only when the pulses are simultaneously observed at four sites.
But our clocks are crystal ones, so the synchronization is doubtful.
(3) The source region of the fields is not located.
The instrument which was developed at CRL could locate the source regions, but after S. Hyogo Pref. EQ of 1995/01/17(M7.2) Japanese Government decided to stop the research on earthquake prediction, and the instrument was discarded.
Observing Sites: On the Pacific Ocean side of central Japan, there are four sites. The distances between them are about 100km
or more. These sites are away from private houses, factories, highways and railroads.
Observing Frequencies: Main frequency is 1.5kHz, which is chosen to avoid the 50 & 60Hz and their harmonics. Additionally
3kHz and 12kHz also observed to reject lightning fields, using the relation E(1.5kHz)>E(3kHz)>E(12kHz), as near lightning
fields have the relation as E(1.5kHz)<E(3kHz) and far ones have the relation as E(3kHz)<E(12kHz).
Observed Pulses before EQ: As the source region was not located, and as from 5th Feb. before EQ to 3rd Mar. after EQ nodata were obtained, so it is doubtful really precursory fields were observed, but the possibility exists that precursor was detected.
The reason is as follows:
From 2/2 22:40 (in the following, time is UT) the pulses were successively recorded three times and farther more from 2/3
00:10 two times. On the contrary, from 4/26 05:00 to 5/25 00:00 for one month no pulse was observed. Namely successively
recording pulses is very rear, so it might be the precursor. Anyway it is essential to locate the source regions of the fields topredict earthquakes.
Ending: The Prediction System of Tokai EQ, which will be M8 or more and is supposed to occur in a few ten years, is basedon the observation that the 5mm level difference during leveling between one day before and on the day of SE Sea EQ of M7.9
on 1944/12/07 (M:7.9). But the late Prof. M. Ikeya repeatedly said that the level difference might be observed not by crustal
movement but the babble movement in the level caused by the change of electric fields at the observing points (K. Takahashi,2004). As in 2011/03/11 EQ no crustal precursor was observed, possibly the prediction system of Tokai EQ is ineffective. As
the researchers on earthquakes in Japan failed to predict or warn not only 2011/03/11 EQ but also Hyogo Pref. EQ (1995/01/17
M7.3), they must be blamed to be swindlers and tax parasites, when they fail to predict coming Tokai EQ. Although crustal
precursors were seldom detected and to the contrary electric ones were often detected, the electric fields are rarely used for theprediction, because their sources are not located. The locating is easy as the method is the same as the locating lightning. Now
lightning fields are identify by their spectrum and man-made ones are rejected by observing at four or more sites.
Reference: Takahashi, K. Quantitatively Showing the Prediction of Tohkai Earthquake to be Illusional. 2004 Japan Earth andPlanetary Science Joint Meeting. S049-012 (2004)
Keywords: earthquake prediction, precursory electric fields, 2011 Far E off Miyagi Pref. EQ

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SSS25-P06

Room:Convention Hall

Time:May 20 17:15-18:30

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