7th International Workshop on
Earthquake Preparation Process~ Observation, Validation,
Modeling, Forecasting ~Program & Abstracts

IWEP7
May 24 – 25, 2023
Chiba University, Chiba, Japan

IWEP77th International Workshop on Earthquake Preparation Process~ Observation, Validation, Modeling, Forecasting ~ (IWEP7)Sponsor
Chiba University, Japan

Co-sponsor
Center for Astronautical Physics and Engineering (CAPE), Taiwan

Supported by
Earthquake Prediction Society of Japan
Electromagnetic Studies of Earthquakes and Volcanoes (EMSEV)National Central University, Taiwan
Chapman University, US
Southern University of Science and Technology, China
Peking University, China

Date:

May 24 – 25, 2023

Venue:

Conference Hall, the 1st floor of Sciences and Technology Building No.1,
Nishi-Chiba Campus, Chiba University, Chiba, Japan

Contacts: Dr. Katsumi Hattori (Chiba University, Japan)+81-43-290-2801

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Contents
Program……………………………………………………1-6
Oral presentations……………………………………1-4
Poster presentations……………………………………5-6

Presentation information………………………………………7
Welcome Party………………………………………………7
Access……………………………………………………7-10
Abstracts…………………………………………………11-62
Oral presentations…………………………………11-45
Poster presentations…………………………………46-62

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Program
May 24, 2023 Morning

0820-0855 Registration
0855-0900 Opening: Dr. Katsumi Hattori

Chair: Dr. Qinghua Huang
0900-0930 Yasuhide Hobara et al., Imminent Precursor of Atmospheric Electric Field
Associated with Earthquakes
0930-1000 Kuniyuki Motojima et al., Statistical association of earthquakes and MF radio
wave propagation anomalies
1000-1020 Yuichiro Ota et al., Development of an LF-band broadband interferometer to
identify LF-band signals related to earthquakes
1020-1030 Coffee break

Chair: Dr. Jann-Yenq Tiger Liu
1030-1100 Masashi Hayakawa et al., Lithosphere–Atmosphere–Ionosphere Coupling
Effects Based on Multiparameter Precursor Observations for February–March
2021 Huge Earthquakes (M~7) in the Offshore of Tohoku Area of Japan (invited)
1100-1130 Kosuke Heki, Predicting earthquake precursors: Case study for the 2023 Turkey
earthquake
1130-1150 Rui Wang et al., Application of earthquake probability prediction model
incorporating regional stress evolution to reservoir earthquakes
1150-1210 Zhiyi Zeng et al., Polarity correction for microseismic event location using
Hilbert transform

1210-1400 *Lunch* Poster session

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May 24, 2023 Afternoon

Chair: Dr. Katsumi Hattori
1400-1430

Toshiyasu Nagao et al., Combining natural time analysis with aspects of nonextensive statistical mechanics to study the seismicity before the 2011 Tohoku
M9 earthquake in Japan - In appreciation of the late Professor Seiya Uyeda's
contribution to earthquake prediction research -1430-1500 Dimitar Ouzounov et al., Multi-parameter precursory patterns associated withthe earthquake sequence in Turkey on February 6th, 2023. [online]
1500-1530 Dragos Armand Stanica et al., Pre-Seismic Geomagnetic Anomalous Signature
Related to the both Mw7.8 and Mw7.5 Kahramanmaras Earthquakes Generated
in Turkey’s South-East Anatolia Region, on February 6, 2023. [online]
1530-1600 Jann-Yenq (Tiger) Liu et al., CESE Detections of M7.0 & M6s Earthquakes andthe Intense Dst-174 nT Magnetic Storm in August 2018
1600-1620 Group photo and coffee break

Chair: Dr. Peng Han
1620-1650 John Rundle, Nowcasting Earthquakes (invited)
1650-1710 Wenchao Li et al., A Study of the ULF seismo-magnetic phenomena in Kakioka,
Japan, during 2015-2020
1710-1740 Jiancang Zhuang, Evaluating earthquake forecasting models with likelihood
based marginal and conditional scores (invited)
1740-1800 Discussion: Dr. Peng Han

1900-2100 Welcome Party (Hotel PortPlaza Chiba)

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May 25, 2023 Morning

Chair: Dr. Xuhui Shen
0900-0920 Hongyan Chen et al., ULF seismo-magnetic signal extraction and evaluation
0920-0940 Zhiqiang Mao et al., Temporal variations of Parkinson vectors in China
0940-1000 Tianxin Lu et al., Slope surface deformation detection by close-range terrestrial
photogrammetry
1000-1020 Akitsugu Kitade et al., Study on Volcanic Activity of Mt. Shinmoedake in 2018
Using Himawari AHI Data
1020-1030 Coffee break

Chair: Dr. Toshiyasu Nagao
1030-1100 Hong-Jia Chen et al., Tatun volcano breathing revealed by continuous
monitoring of selfpotential signals
1100-1130 Ching-Chou Fu et al., Multidimensional Active fault of Geo-Inclusive
observatory - Chihshang (MAGIC) for exploring the earthquake generatingprocess (invited)1130-1150 Shu Kaneko et al., A development of signal discrimination method using Multichannel Singular Spectrum Analysis (MSSA) for ULF band electromagnetic data,
in Boso, Japan
1150-1220 Shih-Sian Yang et al., Lower Ionospheric Disturbances Induced by the 2022
Hunga Tonga–Hunga Ha'apai Eruption: An Application of the Hilbert-Huang
Transform to VLF/LF Data

1220-1400 *Lunch* Poster session

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May 25, 2023 Afternoon

Chair: Dr. Vyacheslav Pilipenko
1400-1430 Xuhui Shen et al., Case studies on Earthquake-related ionospheric anomalies
based on CSES observation (invited)
1430-1500 Victor Novikov et al., Splash of telluric currents generated by solar flare as apossible trigger of earthquakes [online]
1500-1530 Masashi Hayakawa et al., Critical Dynamics in Stratospheric Potential Energy
Variations Prior to Significant (M > 6.7) Earthquakes (AGW hypothesis)
1530-1600 Koichiro Oyama et al., Atmospheric Waves, role of ionosphere modification
before large earthquakes
1600-1610 coffee break

Chair: Dr. Katsumi Hattori
1610-1640 Vyacheslav Pilipenko et al., Towards a closer cooperation between space andseismology communities (invited)
1640-1710 Rui Song et al., The Three-dimensional Ionospheric Disturbances Caused by theM9.0 Tohoku-Oki Earthquake in Japan
1710-1740 Xuemin Zhang et al., The relationship between geomagnetic field observations
and ionospheric perturbations around strong earthquakes in China (invited)[online]1740-1800

Ying Zhang et al., Statistical correlation between DEMETER satellite electronic
perturbations and global earthquakes with M≥4.8

1800-1815 Katsumi Hattori et al., Characteristics of Geomagnetic and Pre-Seismic Changes
in Ionospheric Electron Density over Japan Area
1815-1830 Discussion: Dr. Jann-Yenq Tiger Liu

1830

Closing: Dr. Katsumi Hattori

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Posters
P1:

Tetsuya Kodama et al., Current status of the Prelude: Precursory electric fieldobservation cubesat demonstrator

P2:

Vinod Kumar Kushwah et al., Study of Atmospheric Precursor Anomalies Associatedwith Earthquake Events: Role of Machine Learning

P3:

Kiyotaka Ninagawa et al., Continuous radon measurement in atmosphere at Okayama
and Kiyosumi

P4:

Yoichi Noda et al., Relationship between catfish activities and geophysical changes. (apreliminary report)

P5:

Victor Novikov et al., Physical mechanisms of induced and triggered seismicity: An
implication for electromagnetic triggering of earthquakes

P6:

Vyacheslav Pilipenko et al., Studies of seismo-electromagnetic and seismo-ionosphericeffects at Kamchatka

P7:

Stelios M. Potirakis et al., Criticality analysis of the VLF recordings prior to two strong
earthquakes that happened in central Greece on March of 2021

P8:

Xiaocan Liu et al., The Response of Geomagnetic Daily Variation and Ionospheric
Currents to the Annular Solar Eclipse on 21 June 2020

P9:

Chie Yoshino et al., Multi-sensor monitoring network for earthquake precursor study
near subduction zone at Boso, Japan

P10: Katsumi Hattori et al., ROC Analyses to Assess Pre-earthquake Information in
Ionospheric Electron Density Data Observed by Ionosonde, at Kokubunji, Japan
P11: Katsumi Hattori et al., Soil radon concentration analysis by multi-channel singular
spectrumP12: Shu Kaneko et al., A development of signal discrimination method using Multi-channel
Singular Spectrum Analysis (MSSA) for ULF band electromagnetic data, in Boso, Japan
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P13: Wenchao Li et al., A Study of the ULF seismo-magnetic phenomena in Kakioka, Japan,
during 2015-2020
P14: Yuichiro Ota et al., Development of an LF-band broadband interferometer to identify
LF-band signals related to earthquakes
P15: Akitsugu Kitade et al., Study on Volcanic Activity of Mt. Shinmoedake in 2018 Using
Himawari AHI Data
P16: Katsumi Hattori et al., Characteristics of Spatio-Temporal variation of b-values withstatistical assessment and GNSS-based strain : Application to the 2016 Kumamoto andthe 2011 Tohoku earthquake

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Presentation information:
Oral presentation: 30 or 20 minutes including 5 minutes question-and-answer time.
Poster presentation: Poster board size: 90(W) x 180(H) cm
All the posters will be shown in the conference room during May 24 and 25.

Welcome Party:
Welcome party will be held on May 24, 2023 at "Hotel PortPlaza Chiba", near Chibaminato station (10minutes by car from University). The price will be 8,000 JPY per person (3,000 JPY for a student).

Access:Access to Nishi-Chiba Campus, Chiba University
2-min walk from JR Nishi-Chiba Station to the South Gate of Nishi-Chiba Campus
7-min walk from Keisei Midoridai Station to the Center Gate of Nishi-Chiba Campus
10-min walk from Chiba Monorail Tendai Station to the North Gate

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Abstracts of oral presentations

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Imminent Precursor of Atmospheric Electric Field Associated with Earthquakes
Yasuhide Hobara (1, 2), Mako Watanabe (1), Hiroshi Kikuchi (2), Takuo Tsuda (1, 2),
and Masashi Hayakawa(3, 4)(1) Graduate School of Informatics and Engineering, The University of Electro-Communications, ChofuTokyo, Japan; e-mail: hobara@ee.uec.ac.jp; watanabe.ma1017@gmail.com; takuo.tsuda@uec.ac.jp(2) Center for Space Science and Radio Engineering, The University of Electro-Communications,
Chofu-Tokyo, Japan; e-mail; hkikuchi@uec.ac.jp(3) Hayakawa Institute of Seismo Electromagnetics, Co. Ltd, Chofu-Tokyo, Japan;
e-mail: hayakawa@hi-seismo-em.jp(4) Advanced Wireless & Communication Research Center, The University of Electro-Communications,
Chofu-Tokyo, Japan

In this paper, we report on the near-surface Atmospheric Electric Field (AEF) anomalies immediately before
and after earthquakes (EQs) (within 12 hours) in Japan. Using atmospheric electric field data from spatiallyseparated stations in Japan, we demonstrate the results of a case study for several EQs that occurred close
to the AEF observation site (within 100-200 km of the epicenter) under relatively fair local weather conditions.
We found the common features for different EQs at different field sites e.g. 20~90 min period of clear
anomalous signatures in wavelet spectrograms within a few hours around the main shock. This type of
anomaly is repeatedly observed for the EQs with relatively small magnitude M ~ 5. Statistical results of theoccurrence rate of the AEF anomalies based upon a few hundred EQs support the abovementioned results.
We propose the physical mechanism of the observed electric field anomalies attributed to the Internal Gravity
Waves (IGW) originating from the epicenter region propagating over the field site and disturbing the local
atmospheric electric field.

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Statistical association of earthquakes and MF radio wave propagation anomalies
Kuniyuki Motojima, Yuki Goto
(Graduate School of Science and Technology, Gunma University)
Abstract :Some papers reported about earthquakes and VLF (Very Low Frequency) bandpropagations have showed existence of relation between the both.
On the other hand, we have been monitored broadcasting waves on MF (Middle
Frequency) band over decade at Kiryu, Gunma prefecture in Japan. Propagations on MF band
depend on activity of ionosphere in day time and night time. In normally MF band waves
become stronger around sunset time. However, we have sometimes experienced anomalous
propagations, which have abnormal fluctuations in received waves around sunset time.
Moreover, some days later of the anomalous propagation, seismic activities have sometimes
observed. They might have shown anomaly of bottom of ionosphere preceding earthquakes.
Therefore, we have investigated the relation between occurrence of earthquakes andanomalous propagations in MF band around sunset time. Four broadcasting waves in MF
band are targeted for this investigation, NHK Radio 2 from Akita, STV Radio from Sapporo,
NHK Radio 1 from Osaka and RCC Chugoku Radio from Hiroshima. Propagation distance
range of four waves is from 395 km to 767 km, and they all are domestic radio propagationsin JAPAN.
In normal MF band propagation, the received signal strength shows monotonous increasearound sunset time. But in propagation with anomaly received signal strengths havefluctuations and consequently have peaks before the sunset time. So, we have focused on thetime interval between the peak time of received signal strength and sunset time. Large timeintervals were defined as occurrence of anomalous propagation.
In order to evaluate the relation of both, we adopted statistical items of Hit rate, Prediction
rate, Probability gain and Molchan’s error diagram. As the result of evaluation, it mightshow some existences between earthquakes and anomalous propagation in MF bandbroadcasting waves.
However, we have gotten no physical evidence. Getting them is the future works.

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IWEP7Development of an LF-band broadband interferometer to identify LF-band signals
related to earthquakes
Yuichiro Ota1, Kenshin Miura2, Chie Yoshino 3, Katsumi Hattori 3,4,5, Noriyuki Imazumi6
1. Graduate School of Science and Engineering, Chiba University, Japan
2. Faculty of Science, Chiba University, Japan
3. Graduate School of Science, Chiba University, Japan
4. Center for Environmental Remote Sensing, Chiba University, Japan
5. Research Institute of Disaster Medicine, Chiba University, Japan
6. The Institution of Professional Engineers, Chiba Branch, Japan

Recently, there have been reports of earthquake precursor phenomena related to the LF band. To develop an LF-band
broadband interferometer capable of spatio-temporal estimation of LF-band electromagnetic wave sources, we started
LF-band electromagnetic wave observations using interferometer elements on the rooftop of Chiba University. First, we
conducted a waveform and pulse count survey using one interferometer element and detected an increased number ofpulses before the earthquake which is unlikely to be caused by cloud to ground discharge and typical waveforms during
the time. We also evaluated the performance of three interferometer elements as an interferometer system and found thatthe synchronization system needs to be improved.

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Lithosphere–Atmosphere–Ionosphere Coupling Effects Based on
Multiparameter Precursor Observations for February–March
2021 Huge Earthquakes (M~7) in the Offshore of Tohoku Area
of Japan
Masashi Hayakawa 1,2*, Jun Izutsu 3, Alexander Schekotov 4, Shih-Sian Yang 5, Maria Solovieva 4
1 Hayakawa Institute of Seismo Electromagnetics, Co., Ltd. (Hi-SEM), UEC (The University of Electro-Communications)

Alliance Center #521, 1-1-1 Kojima-cho, Chofu, Tokyo 182-0026, Japan; hayakawa@hi-seismo-em.jp
2 Advanced & Wireless Communications Research Center (AWCC), UEC, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585,

Japan
3 International Digital Earth Applied Science Research Center, Chubu University, 1200 Matsumoto-cho, Kasugai Aichi,
487-8501, Japan; izutsu@isc.chubu.ac.jp
4 The Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, 10-1 Gruzinskaya, 123242 Moscow, Russia;
sasha.schekotov@gmail.com (A.S.); rozhnoi@ifz.ru (M.S.)
5 Department of Space Science and Engineering, National Central University, 300 Jhongha Rd., Jhongli District, Taoyuan
32001, Taiwan; Yang.Sirius.Sian@gmail.com

Abstract:
The purpose of this paper is to discuss the lithosphere–atmosphere–ionosphere coupling (LAIC) effects with the use ofmultiparameter precursor observations for two successive Japanese huge earthquakes (EQs) (with magnitudes of around7) in February and March 2021, respectively, considering a seemingly significant difference in seismological andgeological hypocenter conditions for those EQs. The second March EQ is very similar to the famous 2011 Tohoku EQ
in the sense that those EQs took place at the seabed of the subducting plate, while the first February EQ happened
within the subducting plate, not at the seabed. Multiparameter observation is a powerful tool for the study of the LAIC
process, and we studied the following observables over a 3-month period (January to March): (i) ULF data (lithosphericradiation and ULF depression phenomenon); (ii) ULF/ELF atmospheric electromagnetic radiation; (iii) atmosphericgravity wave (AGW) activity in the stratosphere, extracted from satellite temperature data; (iv) subionospheric VLF/LF
propagation data; and (v) GPS TECs (total electron contents). In contrast to our initial expectation of different responses
of anomalies to the two EQs, we found no such conspicuous differences in the occurrence of electromagnetic anomalies
between the two EQs, but showed quite similar anomaly responses for the two EQs. It is definite that ULF/ELF radiation
happened in the atmosphere and ULF depression as the signature of lower ionospheric perturbation
are most obvious phenomena as precursors to both EQs, and most importantly, all electromagnetic anomalies areconcentrated in the temporal period of about 1 week–9 days before the EQ to the EQ day. There seems to exista chain phenomenon of LAIC process (cause-and-effect relationship) for the first EQ, while all of the observed
anomalies seem to occur nearly synchronously in time for the send EQ. Even though we tried to discuss possible LAIC
channels (chemical AGW channels), we cannot come to any definite conclusion about which coupling channel (orhypothesis) is plausible for each EQ and more information such as Earth’s surface and just above the surface for moredeepened understanding of LAIC process.

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IWEP7Predicting earthquake precursors: Case study for the 2023 Turkey earthquake
Kosuke Heki1,2
1. Shanghai Astronomical Obs., Chinese Acad. Sci., 80 Nandan Rd. 200030, Shanghai, China
2. Dept. Earth Planet. Sci., Hokkaido Univ., N10 W8, Kita-ku, Sapporo, 060-0810, JapanI first briefly review observations and models of ionospheric electron density changes immediately before large earthquakes.
Then I propose a future perspective to validate the series of hypotheses by predicting the attributes (intensity, leading time,locations, etc) of the expected precursors from moment magnitudes of the earthquakes based on their empirical relationships,
and by confirming their consistency with observed changes after the occurrences of large earthquakes. This would serve as an
objective test of the validity of a model when real-time precursor detections are difficult with the available observing systems.
Since its first observation for the 2011 Tohoku-oki earthquake (Heki, 2011 GRL), ionospheric changes immediately before
large earthquakes have been investigated, using ionospheric total electron content (TEC) data from GNSS (global navigation
satellite system) receivers, for many earthquakes with moment magnitudes Mw7.3-9.2 (He and Heki, 2017 JGR). These studies
revealed a positive correlation between Mw and properties of the anomalies including their leading times and intensities (Fig.1).
Based on the 3D structure of positive and negative electron density anomalies in the ionosphere (He and Heki, 2018 JGR),
Muafiry and Heki (2020 JGR) proposed a physical model assuming the downward transport of ionospheric electrons along
geomagnetic fields to cancel electric fields made by surface positive charges. Despite these advances, the model would needobjective tests to draw attention of critical researchers, and I expect this “earthquake precursor prediction” would be effective
for the purpose.
Empirical relationship shown in Fig.1 enables us to specify theproperties of the precursory change of TEC immediately before a
Mw8 event. The intensity of the anomaly would be ~3 percent of
the background VTEC, and the leading time would be ~25
minutes before earthquakes. The physical model let us specify thehorizontal and vertical positions of the anomalies. The positive
and negative electron density anomalies would emerge along the
local geomagnetic field. Here, I “predict” the properties of the
precursory signals for the 2008 Wenchuan earthquake (Mw7.8)
and the 2023 Turkey earthquake (Mw7.9). I will present theanalysis results and demonstrate that the observed signals are
consistent with the properties prescribed based on their Mw.

Fig.1. Leading times (circles) and relative intensities(squares) of the TEC anomalies from past cases.
They scale with the fault lengths and fault areas,
respectively.

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Combining natural time analysis with aspects of non-extensive statistical mechanics
to study the seismicity before the 2011 Tohoku M9 earthquake in Japan- In appreciation of the late Professor Seiya Uyeda's contribution to earthquake prediction research –T. Nagaoa,b, P. A. Varotsosc, N.V. Sarlisc, E.S. Skordasc and M. Kamogawaa,baNatural Disaster Research Section (NaDiR), Global Center for Asian and Regional Research, University of Shizuoka,
3-6-1,Takajo, Aoi-Ku, Shizuoka-City, Shizuoka, 420-0839, Japanb

Institute of Oceanic Research and Development, Tokai University, 3-20-1, Orido, Shimizu-ku, Shizuoka, 424-0902,
Japan

c

Physics Department, National and Kapodistrian University of Athens, Section of Condensed Matter Physics and Solid
Earth Physics Institute, Panepistimiopolis, Zografos, Athens, 15784, Greece

Abstract
Professor Seiya Uyeda passed away on January 19, 2023, at 93. After his retirement from the University ofTokyo, he devoted more than 30 years of his life to research on short-term earthquake prediction. In particular,
as the researcher closest to us, he devoted himself to promoting the VAN method. In his later years, hecontributed to showing that the Natural time [1,2] analysis discussed in this abstract was very effective for the2011 Tohoku earthquake.
Natural time, which is based on a new concept of time termed natural time χ introduced in 2001 [3], identifies
when the system enters the critical stage before major earthquakes. This occurs when the variance 𝜅𝜅1 =〈𝑥𝑥 2 〉 − 〈𝑥𝑥〉2 of natural time becomes equal to 0.070 (as has been theoretically shown in Ref. [4]) a few days
to around 1 week or so before the mainshock occurrence. For example, by applying natural time analysis to
the Japanese seismic data, we have found that this criticality condition (κ1=0.070) is satisfied upon theoccurrence of M=4.2-5.0 earthquakes from 08:36 to 13:14 local time (LT) on 10 March 2011, i.e., almost one
day before the M9 Tohoku earthquake on 11 March 2011. Here, and in order to further shorten this timewindow, we study also the entropy change ΔS under time reversal of natural time analysis as well as the Tsallis
entropy Sq [5] of non-extensive statistical mechanics. We find that, after the aforementioned period from08:36 at 13:14 LT on 10 March 2011 in which the system entered the critical stage, simultaneous changes
appear at 18:00 and 20:00 LT on 10 March 2011 on both quantities ΔS and Sq. These simultaneous changes
are evident when computed in the future epicentral region (which can be estimated well in advance by meansof the procedure developed in Ref. [6]) but can be also seen –but with much difficulty– when thecomputation is made in the entire Japanese region. Finally, a few hours later, and until around 00:00 LT on 11
March 2011 (i.e., several hours before the giant EQ occurrence [6, 7]) precursory changes of the fluctuationsof ΔS have been observed.

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References[1] Varotsos, P.A., Sarlis, N.V., Skordas, E.S.: Natural time analysis: the new view of time. In: Precursory
Seismic Electric Signals, Earthquakes and other Complex Time-Series. Springer, Heidelberg (2011).
https://doi.org/10.1007/978-3-642-16449-1[2] Varotsos, P.A., Sarlis, N.V., Skordas, E.S.: Natural Time Analysis: The New View of Time, Part II,
https://doi.org/10.1007/978-3-031-26006-3_8[3] Varotsos, P.A., Sarlis, N.V., Skordas, E.S.: Spatio-temporal complexity aspects on the interrelation
between seismic electric signals and seismicity. Practica Athens Acad. 76, 294–321 (2001).
[4] Varotsos, P.A., Sarlis, N.V., Skordas, E.S., Uyeda, S., Kamogawa,M.: Natural time analysis of criticalphenomena. Proc. Natl. Acad. Sci. USA 108, 11361–11364 (2011).
https://doi.org/10.1073/pnas.1108138108[5] Tsallis, C.: Possible generalization of Boltzmann-Gibbs statistics. J. Stat. Phys. 52, 479–487 (1988).
https://doi.org/10.1007/BF01016429[6] Sarlis, N.V., Skordas, E.S., Varotsos, P.A., Nagao, T., Kamogawa, M., Uyeda, S.: Spatiotemporalvariations of seismicity before major earthquakes in the Japanese area and their relation with theepicentral locations. Proc. Natl. Acad. Sci. USA 112, 986–989 (2015).
https://doi.org/10.1073/pnas.1422893112[7] Sarlis, N.V., Skordas, E.S., Varotsos, P.A., Nagao, T., Kamogawa, M., Tanaka, H., Uyeda, S.: Minimumof the order parameter fluctuations of seismicity before major earthquakes in Japan. Proc. Natl. Acad. Sci.
USA 110, 13734–13738 (2013). https://doi.org/10.1073/pnas.1312740110

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Multi-parameter precursory patterns associated with the earthquake sequence in Turkey on February 6th, 2023.
Dimitar Ouzounov1, Pavel Kalenda2, Sergey Pulinets3, Xuhui Shen4, Rui Yan5 , Jana Rušajová6
Institute for Earth, Computing, Human and Observing, Chapman University, CA, USA
2
CoalExp, Pražmo, Czech Republic
3
Space Research Institute, RAS, Moscow, Russia
4
National Space Science Center, Chinese Academy of Sciences, China
5
National Institute of Natural Hazards, Beijing, China
6
Institute of Geonics of the Czech Academy of Sciences, Czech Republic

1

The most recent M7.8 earthquake on Feb 6, 2023, struck Turkey/Syria at 03:17 LT, and with a more than 100 km rupture,that was one of the deadliest this decade. A second M7.5 earthquake hit the region nine hours later. We study criticallithosphere/atmosphere /ionosphere coupling processes, the modified Earth’s EM environment, and precede theearthquake events. We combined observations from different non -correlated ground and space monitoring systems forthe first time, such as 1. Vertical static pendulums data from the European network of tiltmeters – vertical static pendulums(Kalenda et al. 2012); /2/ Outgoing long-wavelength radiation (OLR) obtained from NPOESS; 3/ Ionospheric plasma
observations from the China/ Italy Seismo-Electromagnetic Satellite (CSES1); and 4/ Atmospheric chemical potential(ACP) obtained from NASA assimilation models. The deformation anomalies started at all European pendulum
instruments on January 23, 2023(14 days ahead). The most significant anomaly was recorded in cave No.13, Moravian
Karst. This pendulum is directly on the N-S-oriented fault corresponding to the East Anatolian Fault activation (NE-SW),
which was in action. NOAA satellite thermal observations of the epicentral show an increase in infrared radiation startingin December 2022 and riches the maximum on January 13 and Feb 1, 2023(24 and 5 days ahead), near the epicenter ofthe M7.8, compared with the 15 years background level. Increases in OLR from the satellite data coincided with anintensification in the atmospheric chemical potential (Feb 1-4), measured near the epicentral area. The electron density
and oxygen ion density from the Ionosphere plasma instrument of the CSES1 satellite showed an abnormal increase on
January 27-28 (9 days before the earthquake), which is highly correlated with the earthquake occurrence given the stable
space weather index during this period. We show that by combining ground and near-space data accordingly to thephysical concept of the Lithosphere-Atmosphere-Ionosphere Coupling (LAIC), we could identify, on a regional basis,
abnormal patterns of pre-earthquake-related features.

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PRE-SEISMIC GEOMAGNETIC ANOMALOUS SIGNATURE RELATED TO THE BOTH
Mw7.8 AND Mw7.5 KAHRAMANMARAS EARTHQUAKES GENERATED IN TURKEY'S
SOUTH-EAST ANATOLIA REGION, ON FEBRUARY 6, 2023.
Dragos Armand Stanica1 and Dumitru Stanica1
1

Department of Electromagnetism and Lithosphere Dynamics, Institute of Geodynamic of the RomanianAcademy, R-020032 Bucharest, Romania, armand@geodin.ro and dstanica@geodin.ro
A very strong earthquake of Mw7.8 struck the Pazarcik, Kahramanmaraş zone in Turkey’s South-East
Anatolia Region, on February 6, 2023, at 01:17:35UTC. Less than 9 hours later, a second one of magnitude
Mw7.5, centered in Elbistan, was generated at 10:24:49UTC. Almost more than 32,670 buildings havecollapsed, 35,418 people died and 105,500 were injured. Further on, with the aim to identify any anomalous
geomagnetic signature before the onset of the Mw7.8earthquake, we retrospectively analyzed the datacollected on the interval January17 – February 7, 2023 at the two geomagnetic observatories Pedeli (PEG)Greece and Panagjurishte (PAG)-Bulgaria, by using the polarization parameter (BPOL) and the strain effect–
related to geomagnetic signal identification. Thus, for the both observation sites (PEG and PAG), the dailymean distribution of the BPOL and its Standard Deviation (SD) have been carried out using a FFT band-passfiltering in the ULF range. Further on, a statistical analysis based on a standardized random variable equation
was applied for the following two particular cases: a) to assess on the both time series BPOL*(PEG) andBPOL*(PAG) the anomalous signatures related to the above mentioned earthquakes; b) to differentiate
transient local anomaly associated to the both earthquakes, from the internal and external parts of thegeomagnetic field by using the PAG Observatory as reference. Finally, on the both ABSBPOL*(PEG) and
ABSBPOL*(PAG) time series, carried out on the interval January17–February 07, 2023, a very clear anomaly
of maximum, of about 0.9, was identified in February 01, with 5 days before the onset of the Mw7.8earthquake(Fig.1).

12
11
10
9
8
7
6
5
4
3
2
1
0

Earthquake magnitude

07.02.20…

06.02.20…

05.02.20…

04.02.20…

03.02.20…

02.02.20…

01.02.20…

31.01.20…

30.01.20…

29.01.20…

28.01.20…

27.01.20…

26.01.20…

25.01.20…

24.01.20…

23.01.20…

22.01.20…

21.01.20…

20.01.20…

19.01.20…

18.01.20…

17.01.20…

ABS BPOL*(PEG)

ABS BPOL*(PEG) Time Series

y = 3E-06x6 - 0.0002x5 + 0.0044x4 - 0.0554x3 + 0.3676x2 - 1.1853x + 1.5273
R² = 0.5967
1.2
1.1
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0

Fig.1. ABSBPOL*(PEG) time series distribution on the interval 17.01-07.02.2023; red dotted line (y) is 6
degrees’ polynomial regression (indicated by red arrow); R2 is root mean square; red star is earthquake;
7.8/12km is earthquake magnitude/depth; vertical red arrow indicates on 01.02.2023 a pre-seismic anomalous
signature related to the Mw7.8earthquake.
22

IWEP7

CESE Detections of M7.0 & M6s Earthquakes and the Intense Dst-174 nT Magnetic
Storm in August 2018
Jann-Yenq (Tiger) Liu1,2,3, Xuhui Shen4, Fu-Yuan Chang1, Yang-Yi Sun5, Chieh-Hung Chen5, Dimitar Ouzounov8,
Katsumi Hattori7, Sergey Pulinets6
1

Center for Astronautical Physics and Engineering (CAPE), National Central University, Taoyuan City,
Taiwan2
Department of Space Science and Engineering, National Central University, Taoyuan City, Taiwan
3
Center for Space and Remote Sensing Research, National Central University, Taoyuan City, Taiwan
4
Center of Earthquake Observation from Space, Institute of Crustal, Beijing, China
5
Hubei Subsurface Multi-scale Imaging Key Laboratory, Institute of Geophysics and Geomatics, China
University of Geosciences, Wuhan, China
6Center of Excellence in Earth Systems Modeling & Observations, Schmid College of Science & Technology,
Chapman University, Orange, USA
7
Department of Earth Sciences, Graduate School of Science, Chiba University, Chiba, Japan
8
Space Research Institute, Russian Academy of Sciences, Moscow, Russia

The China Seismo-Electromagnetic Satellite (CSES) with a sun-synchronous orbit at 507 km altitude waslaunched on 2 February 2018 to observe seismo-ionospheric precursors (SIPs) and ionospheric space weather.
The CSES probes two manifest longitudinal features of 4-peak plasma density and 3 plasma depletions in theequatorial/low-latitudes as well as mid-latitude troughs. The CSES parameters and total electron content(TEC) of global ionospheric map (GIM) are used to study SIPs associated with a destructive M7.0 earthquake
and its following M6.5 and M6.3/M6.9 earthquakes in Indonesia on 5, 17, and 19, August 2018, respectively,
as well as to examine ionospheric disturbances induced by an intense storm on 26 August 2018. Anomalous
increases (decreases) in the GIM TEC and CSES plasma density (temperature) appear specifically over the
epicenter day 1-5 before the M7.0 earthquake and aftershocks, and however similar TEC and CSES anomalies
occur globally in the southern hemisphere during the storm days of 26-28 August 2018. Spatial analyses on
the CESE plasma discriminate SIPs from magnetic storm effects, and locate the epicenter of possible
forthcoming large earthquakes. The CSES ion velocity shows that the seismo-generated electric fields
associated with the M7.0 earthquake are 0.06-0.21 mV/m eastward and 0.13-0.14 mV/m downward on 1-3
August 2018, while the penetration electric fields during the storm periods of 26-28 August 2018 are 0.17/0.60
mV/m westward/downward at post-midnight of 02:00 LT and 0.26/0.34 mV/m eastward/upward at post-noonof 14:00 LT. CSES ion velocities are useful to derive SIP and storm related electric fields in the ionosphere.

23

IWEP7

Nowcasting Earthquakes
JOHN RUNDLE1,2,3,4
1 Department of Physics, University of California, Davis, CA USA

2 Department of Earth and Planetary Sciences, University of California, Davis, CA USA
3 Santa Fe Institute, Santa Fe, NM USA

4 Visiting Professor, IRIDeS, Tohoku University, Sendai, JapanThe earthquake cycle of stress accumulation and release is associated with the elastic rebound hypothesis proposed by H.F. Reidfollowing the M7.9 San Francisco earthquake of 1906. However, observing details of the actual values of time- and space-dependent
tectonic stress is not possible at the present time. In recent research, we have proposed methods to image the earthquake cycle in
California and in other seismically active regions by means of proxy variables. These variables are based on correlations in patternsof small earthquakes that occur nearly continuously in time, as well as on the time varying rate of occurrence of these same small
earthquakes. Nowcasting is a term originating from economics, finance, and meteorology. It refers to the process of determining theuncertain state of the economy, markets or the weather at the current time by indirect means. In this paper, we describe a simple twoparameter data analysis that reveals hidden order in otherwise seemingly chaotic earthquake seismicity. One of these parameters relates
to a mechanism of seismic quiescence arising from the physics of strain-hardening of the crust prior to major events. We observe an
earthquake cycle associated with major earthquakes in California, similar to what has long been postulated. An estimate of theearthquake hazard revealed by this state variable time series can be optimized by the use of machine learning in the form of the Receiver
Operating Characteristic skill score. The ROC skill is used here as a loss function in a supervised learning mode. Our analysis isconducted in the region of 5° × 5° in latitude-longitude centered on Los Angeles, a region which we used in previous papers to build
similar time series using more involved methods (Rundle & Donnellan, 2020, https://doi.org/10.1029/2020EA001097; Rundle, et al.,2021a, https://doi.org/10.1029/2021EA001757; Rundle, Stein et al., 2021, https://doi.org/10.1088/1361- 6633/abf893). Here we showthat not only does the state variable time series have forecast skill, the associated spatial probability densities have skill as well. In
addition, use of the standard ROC and Precision (PPV) metrics allow probabilities of current earthquake hazard to be defined in a
simple, straightforward, and rigorous way. The workflow for this process is shown in the figure below.

24

IWEP7

A Study of the ULF seismo-magnetic phenomena in Kakioka, Japan,
during 2015-2020*Wenchao Li1, Shu Kaneko1, Chie Yoshino2, Katsumi Hattori2，3，4

1. Graduate School of Science and Engineering, Chiba University, Japan
2. Graduate School of Science, Chiba University, Japan
3. Center for Environmental Remote Sensing, Chiba University, Japan
4. Research Institute of Disaster Medicine, Chiba University, Japan

Abstract:
To mitigate earthquake disasters, the establishment of the short-term earthquake forecast technique isimportant. To achieve this, the ultra-low frequency (ULF) geomagnetic field changes has been studied andstatistical significance in correlation and precursor characteristics in ROC analysis have been presented, Itmeans that the ULF geomagnetic measurement has a potential parameter for the short-term earthquake
forecast. In previous studies, the data observed Kakioka station during 2001-2010 operated by JMA has beenutilized. In order to clarify ULF seismo-magnetic phenomena, we have studied the geomagnetic data observedat the Kakioka (KAK) station, Kanto, Japan, during 2015-2020. The magnetic data and earthquake catalogs
obtained from Japan Meteorological Agency. The same approach with the previous studies have been
performed, To select earthquakes, we use the Es parameter which considers the magnitude and distance of anearthquake simultaneously to select statistical samples. As the frequency of original geomagnetic data is 1Hz,the method of wavelet transform was implemented, and extract the signals at the frequency around 0.01Hz.
Ground-based ULF geomagnetic data are a superposition of several signals: global magnetic perturbations,artificial noises, and magnetic signals possibly due to underground activities. To minimize artificial noises, weselected the midnight time data (JST 1:30-3:30). And to reduce the influence of global magnetic perturbations,the station Kanoya (KNY) was chosen as reference station. Then the statistical method of superposed epoch
analysis (SEA) was adopted to highlight the weak but significant signal from noisy data. Finally, to verify theusefulness of the prediction model compared with random prediction. We evaluated the precursory
information of ULF geomagnetic signals for local sizable earthquakes using statistical method receiver
operating characteristic (ROC) curve. In ROC curve, the closer to the upper left corner, the better performing
for this prediction model.
Keywords: ULF electromagnetic phenomena, Superposed Epoch Analysis(SEA), Molchan's Error Diagram

25

IWEP726

IWEP727

IWEP7
ULF seismo-magnetic signal extraction and evaluation
1

1

2

Hongyan Chen , Peng Han , Katsumi Hattori

1. Southern University of Science and Technology, China
2. Chiba University, Japan
Content: The early research on the anomaly of seismo-magnetic signal mainly focused on the spectrum analysis of theoriginal data of the station, and then PCA and other methods were developed. In recent years, with the application of
far reference station, the anomaly index of P value for the ratio of the observed data energy to its model energy has
been established, and the anomaly index P value is dimensionless. It is worth thinking whether the actual abnormal
waveform can be obtained. However, the seismo-magnetic signal is weak, it is usually mixed with the space sources
signal and human noises, so the critical problem is distinguishing the seismo-magnetic signal from the complex
environment. It is a potential method to extract the signal of observation stations by using the reference station data
based on interstation transfer function. In view of the previous studies, which did not use strict multivariate coherence
analysis for the transfer function, this study proposed an interstation transfer function algorithm based on wavelet
multivariate coherence to establish the electromagnetic estimated values of observation stations, and the transfer
function in the high-frequency part can also be accurately calculated. The phase difference is estimated well and theactual waveform data of the seismo-magnetic signal can be obtained.
For Kakioka (KAK) station, the data of KNY and MMB stations are used as reference stations to calculate the interstationtransfer function and obtain the estimated values of the three components of the KAK station. By showing thegeomagnetic pulsation caused by obvious global disturbance at both the observed and reference stations, thegeomagnetic pulsation signal disappears in the residual between the observed and the estimated value. By adopting
the SEA method, the anomalies of seismo-magnetic signal before the earthquake show significance. On the basis ofcorrelation analysis, the Molchan diagram was used to evaluate the precursor information in the observed data. The
residual values between vertical observed values and estimated values are significantly increased in the total residual,
the 50s, 100s, 200s, and 400s periodic of the total residual on 6-15 days before the earthquake. The forecasting
efficiency of the above parameters are better than that of the random prediction, and the forecasting efficiency of thetotal residual and 400s is the best.

28

IWEP7

Temporal variations of Parkinson vectors in China
Zhiqiang Mao1, Chieh-Hung Chen1, Aisa·Yisimayili2
1. China University of Geosciences (Wuhan), Wuhan, Hubei, 430074
2. Earthquake Agency of Xinjiang Uygur Autonomous Region, Urumqi, Xinjiang, 830011
Parkinson vector (or induction vector) is an effective indicator to investigate the underlying conductivity
structures and pre-earthquake conductivity anomalies. Typically, the factors influencing Parkinson vectors(PVs) come from underground. Recently, the seasonal effects have been observed in the PVs. However,causal mechanisms of the seasonal effects on the PVs are not fully understood. In this study, we utilize ten
years three-component geomagnetic data from 24 stations operated by the Geomagnetic Network of China to
study the spatiotemporal characteristics of the PVs through vertical transfer function (VTFs). The analyticalresults show that the PVs exhibit seasonal variations that the magnitude of PVs reach maximum in summer
and winter, which are pronounced in lower frequency bands. In addition, the PVs at all stations consistently
exhibit a counterclockwise rotation in June (summer), and a clockwise rotation in December (winter). The
Inter-hemispheric field-aligned current in the ionosphere is one of the potential reasons to explain the seasonalvariations. This study finds that the PVs are also affected by ionospheric current systems. As a result, theseasonal effect on PVs should be examined when we study the pre-earthquake conductivity anomalies.

29

IWEP730

IWEP7
Study on Volcanic Activity of Mt. Shinmoedake in 2018 Using Himawari AHI Data
Akitsugu Kitade1, Shu Kaneko1, Chie Yoshino2, and Katumi Hattori2,3,4
1. Graduate School of Science and Engineering, Chiba University, Japan
2. Graduate School of Science, Chiba University, Japan

3. Center for Environmental Remote Sensing, Chiba University, Japan
4. Research Institute of Disaster Medicine, Chiba University, Japan

Ground-based volcano monitoring is not possible for all active volcanoes due to topographical restrictions
and cost. On the other hand, volcanic activities that cause lava eruptions or eruptions that cause significant
human and economic damage are usually accompanied by an increase in surface temperature, making satellite
remote sensing effective for temperature monitoring. Therefore, we have been developing algorithms todetect temperature anomalies associated with volcanic activities (especially for monitoring lava activities thatcause serious damage to human lives and predicting pyroclastic flows) by spatiotemporal analysis of groundsurface temperature around volcanoes using thermal infrared nighttime data on board artificial satellites. As aresult, Noguchi et al. (2004) demonstrated the effectiveness of monitoring volcanic activity in the tropics1
using nighttime infrared data from the MODIS sensor onboard the Aqua/Terra satellites, and Tsutsumi et al.
(2020) showed that the appearance of a lava dome on the 2011 eruption of Mt.shinmoe In a similar analysis
to Tsutsumi et al. (2020) for the eruptive activity of Mt. Shinmoe in 2018, an anomalous rise in surface
temperature associated with the appearance of a lava dome was detected, but the anomalous rise in surface
temperature was not detected visually or by SAR data. The reason for this may be that the summit area wascovered by clouds at the time of the satellite observations, which prevented observation of the ground surface.
There are two possible means of measuring surface temperatures in consideration of cloud effects: using
satellite-observed microwave data and increasing the frequency of observations at target locations using
geostationary meteorological data to increase the number of cloud-free observations. The former is promising,
but requires a large footprint, since microwaves can penetrate clouds. The latter is promising, but the footprint
becomes large. The latter is affected by clouds, but the observation frequency is every 10 minutes (2.5 minutes
near Japan) (in the case of Himawari No. 8-9).
Therefore, by using thermal infrared data from the Himawari-8 satellite, which has a higher temporal
resolution, we conducted a research study to contribute to the detection of surface temperature anomalies
associated with magma eruptions and the appearance of lava domes, and to their detection as early as possible.
As a result, we were able to confirm the temperature anomaly several hours before the eruption occurred.

31

IWEP732

IWEP733

IWEP734

IWEP7A development of signal discrimination method using Multi-channel Singular Spectrum
Analysis (MSSA) for ULF band electromagnetic data, in Boso, Japan
Shu Kaneko1, Toru Mogi2, Chie Yoshino2, Katsumi Hattori2,3,4
1. Graduate school of Science and Engineering, Chiba University, Japan
2. Graduate school of Science Chiba University, Japan
3. Center for Environmental Remote Sensing, Chiba University, Japan
4. Disaster Medicine Research Institute, Chiba University, JapanAn electromagnetic phenomenon associated with crustal activity in the ULF band (f < 10 Hz) is expected
as a method that can detect the signal directly from the intra-crust or plate boundary. However, the observed
signal includes not only the earthquake-related signal but also the solar-origin signal and artificial noise,such as the leak current from the DC-driven train. Detection of the signal is difficult because the amplitudeof the earthquake-related signal is tiny compared with the other noises, and the waveform of the signal issimilar to the artificial noise. Recent analyses were performed in a noiseless environment, such as the region
far from the city area, and at night-time to escape this problem. However, by this scheme, we miss detecting
the signal that occurs in the daytime. The new signal discrimination method is essential to increase thechance of detecting the signal in the daytime.
We are developing a new signal discrimination method based on Multi-channel Singular Spectrum
Analysis (MSSA) to overcome this problem. MSSA is the extension of Singular Spectrum Analysis (SSA),
resulting in MSSA can decompose multiple time series to several principal components (PCs). Then, choosing
and summing arbitrary PCs with some threshold, such as correlation and contribution ratio of the PCs, thetime series can be discriminated into the signal and noise parts.
In the MSSA-based signal discrimination method developed in this study, remove solar-origin signals from
7ch data (target site 5 components (horizontal magnetic field 2ch (Hx and Hy), vertical magnetic field 1ch(Hz), and horizontal electric field 2ch (Ex and Ey)) and reference site 2ch (magnetic field 2ch (Rx and Ry))),then, obtain a local signal. After applying this method to actual data acquired on the Boso Peninsula forsignals with a period of less than 400 s, the solar-origin signal was removed, and a local signal of about 1 nT
for the magnetic field and about 2 mV/km for the electric field was detected. This presentation will focus on
the performance and effectiveness of the method.

35

IWEP7Lower Ionospheric Disturbances Induced by the 2022 Hunga Tonga–Hunga Ha'apai Eruption: An
Application of the Hilbert-Huang Transform to VLF/LF Data
Shih-Sian Yang1, Sudipta Sasmal2, Stelios M. Potirakis3,4, and Masashi Hayakawa5,6
1

Department of Space Science and Engineering, National Central University, Jhongli, Taoyuan 320317,
Taiwan2Institute of Astronomy Space and Earth Science, AJ 316, Sector II, Salt Lake, Kolkata 700091, India
3
Department of Electrical and Electronics Engineering, University of West Attica, Ancient Olive Grove
Campus, 12241 Aigaleo, Greece
4
Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory ofAthens, Metaxa and Vasileos Pavlou, 15236 Penteli, Greece
5
Hayakawa Institute of Seismo-Electromagnetics, Co. Ltd. (Hi-SEM), University of ElectroCommunications (UEC) Alliance Center #521, 1-1-1 Kojima-cho, Chofu, Tokyo 182-0026, Japan
6
Advanced Wireless and Communications Research Center, UEC, 1-5-1 Chofugaoka, Chofu, Tokyo 1828585, JapanThe Tongan Hunga Tonga–Hunga Ha'apai (HTHH) volcano (20.6°S 175.4°W) erupted on 15
January 2022. This eruption, with a volcanic explosivity index (VEI) of 5–6, is considered the strongest after
the 1991 Pinatubo eruption. Our very low frequency/low frequency (VLF/LF) receiving system in Taiwan,
which is used to monitor VLF/LF signals on several propagation paths in the Asia-Pacific region, recorded
unusual variations in VLF/LF receiving amplitudes about 7–15 hours after the eruption, suggesting the lower
ionosphere was disturbed by oscillations induced by the volcanic eruption. The unusual variations in
amplitudes started after the arrival of the so-called “Lamb wave,” and the arrival time of the wave can be easily
determined by carefully checking the amplitude time series. The fluctuations in VLF/LF amplitudes were
sustained for about 8 hours after the passage of the Lamb wave, indicating that the lower ionosphere wascontinuously disturbed by volcano-induced atmospheric oscillations during this period. Nevertheless, theamplitude time series on the four studied propagation paths present their respective variations. Therefore, it isdifficult to coordinate those results and conclude the properties of the atmospheric oscillations using
conventional time-frequency analyzing methods, such as Fourier and Wavelet transforms. In such a situation,
we used the Hilbert-Huang transform (HHT), which is an algorithmic method for analyzing nonlinear andnon-stationary time series and has never been applied to VLF/LF data in previous studies. We successfully
decomposed the time series and found modulations of the oscillatory amplitude and period from intrinsic
mode functions (IMFs). These modulations are considered to be changes in the properties of atmosphericoscillations, and further, the possible mechanisms of these changes are discussed in this study. It seems the airsea coupling plays an important role in affecting the amplitude and period of atmospheric oscillations. The
present study is the first attempt to employ the HHT to analyze VLF/LF data. As the performance of HHT iswell demonstrated in this study, we think that the HHT can be a good tool to detect pre-seismic features hiddenin the VLF/LF time series in our feature studies.

36

IWEP7

Case studies on Earthquake-related ionospheric anomalies based on CSES
observation
Rui Yan1, Zeren zhima1, Xuhui Shen2, Jianping Huang1, Wei Chu1,
Song Xu1, Zhenxia Zhang1, Dapeng Liu1, Qiao Wang1, Yanyan Yang1,
Hengxin Lu1, He Huang1, Jian Lin1
1National Institute of Natural Hazards, The Ministry of Emergency Management of China, Beijing, China
2National Space Science Center, Chinese Academy of Science, Beijing, China

Abstract:
The CSES is the first satellite of the space-based observation platform of China's three-dimensional earthquake
observation system. It can carry out real-time monitoring of ionospheric dynamics and tracking of earthquake
precursors in China and surrounding regions by acquiring global electromagnetic field, ionospheric plasmaand energy particles to make up for the shortage of ground-based observation and open up new ways to explore
earthquake monitoring and prediction.
The CSES team has carried out a retrospective study of earthquake cases, including 47 shallow earthquakes
with Ms≥7 (depth<100km) and 15 earthquakes with Ms≥6 in Chinese mainland since February 2, 2018. The
results show that the Langmuir probe and the electric field have the highest number of anomalously identified
earthquake cases, and the anomalously identified rate is more than 70%; Followed by the two instrument,
high-energy particle detector and GNSS occultation receiver, with anomaly recognition rate of around 50%.
For electromagnetic fields, anomalies mainly are observed in the ULF and ELF frequency range. For plasma,density will show more anomalies than the temperature. The electron flux is the main parameter more sensitive
to earthquakes for energy particles. For all instruments, the positive variation is the major variation. The
appearing time of the anomalies are mainly focus on the day to 7 days before the earthquake occurring, andduring 11~ 15 days before the earthquake occurring, in addition, for the electromagnetic field, the anomalies
also appears the 20~25 days before the earthquake occurring. The location of the anomalies generally appears
more to the east and south of the epicenter.
Although obvious seismic ionospheric anomalies can be recorded by the CSES, it is still a world scientificproblem to achieve accurate prediction of time, position and intensity of earthquakes, especially only using asingle satellite. The combination of seismology, electromagnetism, geodesy, geochemistry and other multidisciplinary means can better promote the research in this field.

Keywords:
CSES, seismic ionospheric anomalies, Electromagnetic fields, plasma, energy particles

37

IWEP7Splash of telluric currents generated by solar flare as a possible trigger ofearthquakes
Victor Novikov1, Valery Sorokin2, Alexey Yaschenko2, and Georgy Mushkarev2
1

2

Joint Institute for High Temperatures, Russian Academy of Sciences, 125412 Moscow, Russia
Pushkov Institute of Terrestrial Magnetism, Ionosphere, and Radio Wave Propagation, Russian Academy of Sciences,108840 Moscow, Russia
Abstract

The current studies of solar-terrestrial relations and possible impact of space weather on the seismic activity are based on
statistical analysis without detailed consideration of possible physical mechanisms that results in contradictory
conclusions. We propose to consider a hypothesis of electromagnetic triggering of earthquake by a sharp rise of telluric
currents in lithosphere including conductive crust faults due to interaction of solar flare X-ray radiation with "ionosphereatmosphere-lithosphere" system resulted in a rise of telluric currents in the crust faults. This hypothesis is based on field
and laboratory experiments carried out in Russia within the last forty years that clearly demonstrated a possibility ofearthquake triggering by electric current injected into the crust fault [1]. We developed a mathematical model andcomputer code for numerical estimations of telluric currents generated by solar flare radiations [2, 3]. The obtained
numerical results show that solar flares can cause variations in the density of telluric currents in the crust faults, comparable
to the current densities generated in the Earth’s crust by artificial pulsed power sources capable to trigger earthquakes.
Based on obtained numerical results, in our opinion, the further correct statistical correlation analysis of solar-terrestrial
relations should be carried out in the following sequence: (a) determination of an unstable area (the crust fault section)
where the strong earthquake is anticipated based on existing methods of selection of regions with impending strong
earthquakes (long- and medium-term predictions); (b) selection of the crust faults in the areas determined in step a)favorable for generation of maximal telluric current density from point of view of their orientation close to direction of
the current density vector, as well as their electrical conductivity; (c) sampling the earthquakes from regional seismic
catalogs which occurred on the faults selected according to step b); (d) correlation analysis of earthquake occurrence andvariations of space weather parameters. Such a statistical approach will provide an estimation of space weather parameterscapable to trigger earthquakes in the specific seismic-prone areas sensitive to electromagnetic impact from point of viewof orientation of crust faults and their electrical conductivity.
This work was supported by the Ministry of Science and Higher Education of the Russian Federation (State Assignments
No. 075-01129-23-00 and No. 01201356396)

References:
1. Zeigarnik, V.A.; Bogomolov, L.M.; Novikov, V.A. Electromagnetic Earthquake Triggering: Field
Observations, Laboratory Experiments, and Physical Mechanisms—A Review. Izv. Phys. Solid
Earth 2022, 58, 30–58.
2. Sorokin, V.M.; Yashchenko, A.K.; Novikov, V.A. A possible mechanism of stimulation of seismic activity
by ionizing radiation of solar flares. Earthq. Sci. 2019, 32, 26–34.
3. Sorokin, V.; Yaschenko, A.; Mushkarev, G.; Novikov, V. Telluric Currents Generated by Solar FlareRadiation: Physical Model and Numerical Estimations. Atmosphere 2023, 14, 458.

38

IWEP7

Critical Dynamics in Stratospheric Potential Energy Variations
Prior to Significant (M > 6.7) Earthquakes(AGW hypothesis)
Dimitrios Z. Politis 1, Stelios M. Potirakis 1,2*, Subrata Kundu 3, Swati Chowdhury 3, Sudipta Sasmal 4
and Masashi Hayakawa 5,6
1 Department of Electrical and Electronics Engineering, Ancient Olive Grove Campus, University of West Attica, GR-12244

Egaleo, Greece
2 Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory of Athens, Metaxa
and Vasileos Pavlou, Penteli, GR-15236 Athens, Greece
3 Department of Ionospheric Sciences, Indian Center for Space Physics, 43 Chalantika, Garia 6 Station Road, Kolkata
700084, India
4 Institute of Astronomy, Space and Earth Science, AJ 316, Sector II, Salt Lake, Kolkata 700091, India
5 Hayakawa Institute of Seismo Electromagnetics, Co., Ltd., UEC Alliance Center #521, Kojima-cho 1-1-1 Chofu, Tokyo
182-0026, Japan
6 Advanced Wireless Communication Research Center, The University of Electro-Communications (UEC), 1-5-1
Chofugaoka, Chofu, Tokyo 182-8585, Japan

Abstract:
Lithosphere–atmosphere–ionosphere coupling (LAIC) is studied through various physical or chemical quantities,
obtained from different sources, which are observables of the involved complex LAIC processes. LAIC has been
proposed to be achieved through three major channels: the chemical, the acoustic (AGW), and the electromagnetic.
Accumulated evidence supporting the acoustic (AGW) channel hypothesis has been published, while atmosphericgravity waves (AGWs) play a key role in LAIC as the leading mechanism for the transmission of energy from the lower
atmosphere to the stratosphere and mesosphere, associated with atmospheric disturbances observed prior to strong
earthquakes (EQs). The seismogenic AGW is the result of temperature disturbances, usually studied through stratosphericpotential energy (EP). In this work, we examined 11 cases of significant EQs (M > 6.7) that occurred during the last 10
years at different geographic areas by analyzing the temperature profile at the wider location of each one of the examined
EQs. The “Sounding of the Atmosphere using Broadband Emission Radiometry” (SABER) instrument, a part of the“Thermosphere Ionosphere Mesosphere Energetics Dynamics (TIMED)” satellite, data were employed to compute thepotential energy (EP) of the AGW. Using the temperature profile, we first calculated EP and determined the range ofaltitudes for which prominent pre-seismic disturbances were observed. Subsequently, the EP time series at specificaltitudes, within the determined “disturbed” range, were for the first time analyzed using the criticality analysis method
termed the “natural time” (NT) method in order to find any evidence of an approach to a critical state (during a phasetransition from a symmetric phase to a low symmetry phase) prior to the EQ occurrence. Our results show criticality
indications in the fluctuation of EP a few days (1 to 15 days) prior to the examined EQs, except from one case. In ourstudy, we also examined all of the temperature-related extreme phenomena that have occurred near the examined
geographic areas, in order to take into account any possible non-seismic influence on the obtained results.

39

IWEP7
Atmospheric Waves, role of ionosphere modification before large earthquakes
Koichiro Oyama1,2, C.H. Chen3, and Yang-Yi. Sun4
1. Co.Ltd. Asia Space Environment Research Consortium, Hashimoto, Kanagawa
2. International Center of Space and Planetary Environmental study, Kyushu University, Fukuoka
3. Department of Earth Science, National Cheng Kung University, Taiwan
4. Institute of Geophysics and Geomatics, China University of Yang. Yi 430074, China
We reported that all ionosphere disturbance which is seen before large earthquake is explained by “enhanced dynamo
electric field”. (Oyama et al., 2019). The process to the enhanced electric field is: 1. Enhanced dynamo electric field iscaused by the increased electric resistivity of the dynamo region, 2. which is generated by the enhanced plasma
irregularities. 3. The enhanced plasma irregularities is generated as the existence of neutral density irregularities, 4. which
is produced as the breaking of the atmospheric waves. The paper concentrates to discussed the role of the waves, and theorigin of the waves.
Our study on the possible candidate to modify the ionosphere starts from the finding of the good correlation between
NmF2 and variation of neutral temperature, Tn. Tn were observed by TIDI (TIMED Doppler Interferometer) instrument
onboard US satellite,TIMED (Thermosphere、Ionosphere, Mesosphere Energetics and Dynamics Mission) (Sun et al.,2015). The wavy structure of large amplitude and small-scale neutral irregularities was studied. Tn around the height of
100-110 Km for Sechuan earthquake, which occurred in 12 May 2008 (31.02° N,103.367°E, Ms8.0, Mw7.9, 31D19 km)
shows the increase of NmF2 corresponding to the increase of the amplitude of Tn variation. The Tn variation of verticalwave length less than 20 km shows the broad peak around 100 km. The irregularities thus produced contributes to the
reduction of the electric conductivity (Prakash,1999). We conclude that this irregularity finally enhances the dynamo
electric field.
Study on the role of atmospheric waves which we conducted for Sechuan earth quake was applied to the Tohoku-Oki
earth quake which occurred on 11 March 2011(38.297°N,142.373°E, Mw=9.1, D29 km). We confirmed that atmosphericwave is the main player to modify the ionosphere. Although we do not exclude other mechanism for ionosphere
disturbance, two days oscillation of NmF2(considered to be possible interaction between atmospheric waves) appears,
for one week before earth quake both for Tohoku-Oki and Kumamoto earthquake, which occurred at 21:26 on 14April
2016 (JST), at 32°44.5’N /130°48.5’E, Mj6.5, Mw6.2, D11 km), and 1:25 on 16 April (32.782N,130.726E,
Mj7.3Mw7.06D12Km. The two days oscillation suggests the possible role of atmospheric waves. The two days
oscillation might be generrated as a result of the interaction between the earthquake triggered wave and existing waves(Pancheva et al., 2006). The origin of the atmospheric wave will be discussed in detail in another time.
References
Oyama, K.-I., C. H. Chen, L. Bankov, D. Minakshi, K. Ryu, J. Y. Liu, and H. Liu, Precursor effect of March 11 2011 off thecoast of Tohoku earthquake on high and low latitude ionospheres and its possible disturbing mechanism, Advances SpaceRes., 63, 2623-2637, 2019, https://doi.org/10.1016/j.asr.2018.12.042.
Oyama, K. -I., and M. Devi, Study of Anomalous behavior of ionosphere prior to large earth quakes – Present and Future,
Space Res. Today, 2020 August Issue, No 208, 36- 43, 2020.
Pancheva, D. V., P.J. Mukharov, M. G. Shepherd, N. J. Michel, D. C. Fritts, D. M., Riggins, S J. Franke, P. P. Batista, M.A.
Abdu, I. S. Batista, B. R. Clemensha, and T. Kikuchi, Two-day wave coupling of the low-latitude atmosphere-ionospheresystem, J. Geophys. Res., 111, A07313, doi:10.1029/2005JA011562, 2006.
Prakash, S., Production of electric filed perturbations by gravity wave winds in the E region suitable for initiating equatorial
spread F, J. Geophys. Res., 104, A5,10051- 10069, 1999.
Sun, Y.Y., K. -I. Oyama, J. Y. Liu, H. K. Jhuang, and C. Z. Cheng, The Neutral Temperature in the Ionospheric Dynamo
Region and the Relation with the Ionospheric Density during Wenchuan and Pingtung Earthquakes, Nat. Hazard. Earth
Syst. Sci., 11, 1759- 1768, 2011, 10.1007/s11589-015-0131-2, 2015.
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Towards a closer cooperation between space and seismology communities
Vyacheslav Pilipenko
Institute of Physics of the Earth, Moscow (pilipenko_va@mail.ru)
Kazuo Shiokawa
ISEE, Nagoya University (shiokawa@isee.nagoya-u.ac.jp)
The space physicists and the earthquake prediction community exploit the same instruments – magnetometers,
but for different tasks: space physicists are trying to comprehend the global electrodynamics of the near-Earthspace on various time scales, whereas the seismic community develops electromagnetic methods of shortterm earthquake prediction. However, the lack of deep collaboration between those communities may result
sometimes in misleading conclusions. In this talk we demonstrate some incorrect results caused by a neglectof specifics of geomagnetic field evolution during space weather activation. Specific examples comprise:- Magnetic storms as a trigger of earthquakes;- Global ULF waves occurring several tens of mins before strong earthquakes;- Immediate (several minutes) geomagnetic impulses before seismic shocks;- Long-period geomagnetic disturbances generated by strong earthquakes;- Discrimination of underground ULF sources by amplitude-phase gradients;- Depression of ULF power as a short-term (several days) earthquake precursor.
To verify the reliability of the above phenomena, we have used data from the PWING network of induction
magnetometers in the Far East, augmented by data from world-wide array of fluxgate magnetometers. In
these events, the ULF behaviour can be explained by global geomagnetic activity, and it is apparently not
associated with seismic activity. We suggest that both communities must cooperate their studies more
tightly (data exchange, combined usage of magnetometer networks, CDAW of unique events, etc.).

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The Three-dimensional Ionospheric Disturbances Caused by the M9.0 TohokuOki Earthquake in Japan
Rui Song1, Katsumi Hattori1,2,3, Xuemin Zhang4, Jann-Yenq Liu5
1

Graduate School of Science, Chiba University, Japan

2 Center for Environmental Remote Sensing, Chiba University, Japan

Research Institute of Disaster Medicine, Chiba University, Japan
Institute of Earthquake Forecasting, China EarthquakeAdministration, China
5 Institute of Space Science, National Central University, Taiwan
3

4

In this study, we reconstructed the three-dimensional (3-D) ionospheric disturbances of electron density(Ne) induced by the M9.0 Tohoku Earthquake in 2011 using the computerized ionospheric tomography
technique. The reproduced Ne distributions around 06:00 - 06:10 UT exhibited significant uplift with adisplacement of ~30 km in the F layer along the longitude of 138° - 141°E, which corresponded to a sudden
depletion of Ne when Rayleigh wave-induced traveling ionospheric disturbances (TIDs) was passing through.
At 06:12 UT, abrupt uplift of the F layer with sharp slope was detected in 137.5°E. Then, it propagated awayfrom the epicenter and appeared in 136°E at 06:24 UT. From then on, the Rayleigh wave-induced ionosphericdisturbances became dispersive, and the tsunami-induced disturbed structures became prominent. During
06:34 - 06:52 UT, the mesoscale TIDs associated with tsunami gradually came out from 06:34 UT with aremarkable sinusoidal waveform in 250 - 400 km. The distribution of detrended Ne presented several
prominent negative and positive bands, which were closely following along 132° - 141°E in a similar heightinterval. Further, the downward phase progression with increasing time was significantly detected in the timeheight distribution of the filtered Ne related to the tsunami waves generated by offshore earthquake, whichstrongly indicated the signature of the upward propagation of the atmospheric gravity waves in accord with
the numerical simulated results. Finally, by virtue of the reproduced vertical wavelength and dispersion
equation, we estimated a background neutral wind of -49.3 m/s for the tsunami case (negative values represent
northward propagation). The estimated neutral wind velocity is consistent with the usual values ranging from-100 m/s to 100 m/s.

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The relationship between geomagnetic field observations andionospheric perturbations around strong earthquakes in China
Xuemin Zhang1, Xuhui Shen2, Jianhai Ding1
1

Institute of Earthquake Forecasting, China Earthquake Administration, Beijing 100036, China

2

National Space Science Center, China Academy of Sciences, Beijing 100190, China

Abstract: As proposed concepts in LAIC processes, three channels have been suggested, one for chemical channel ornamed overlapped electric field channel, one for acoustic gravity wave channel, and the last one for ULF
electromagnetic wave channel, where the first channel is widely accepted to explain the ionospheric plasma
perturbations, especially for their magnetic conjugate characteristics. But due to the low conductivity of the air, thestrength of electric field up to the lower ionosphere is limited or quite small. Here on the basis of ground-based
geomagnetic field observations, we collected the multi parameters in ionosphere from ionosonde or satellites. The
signals around a few strong earthquakes in China have been analyzed, including Mani in 1997, Kunlunshan in 2001,
Wenchuan in 2008, Yangbi in 2021, and it is found that when the significant perturbations occurred in ionosphere, thegeomagnetic field observations always exhibited simultaneous disturbances, including their amplitude and phase in its
diurnal variations. We try to construct their intrinsic correlation, and the occurrence of new current system under theseismic preparation region is recommended to overlapped on the internal source current system to cause theincreasing or reducing of the geomagnetic field in vertical component or directly to change the diurnal variation phasesuch as the lowest point time displacement or double low points in one day. After separating of equivalent current
system for external and internal sources from Sq in geomagnetic field, underground current in seismic region is
illustrated for the lithosphere and ionosphere coupling, especially for the origin of long period disturbances more than
1h in lithosphere and ionosphere.

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Statistical correlation between DEMETER satellite electronic perturbations and global
earthquakes with M≥4.8
Ying Zhang1 and Qinghua Huang1
1.

Department of Geophysics, School Earth and Space Sciences, Peking University, Beijing 100871, China.

Upon obtaining a relatively low false discovery rate (FDR) of alarms and a low false negative rate (FNR) of
earthquakes, several previous long-term statistical researches concluded that ionospheric perturbations
recorded by satellites are statistically related to earthquakes. However, overly large time-space windows forcorrelating perturbations with earthquakes will also contribute to low FDR and FNR. In this study, a new score- the number of non-randomly successful alarms - is used to quantitatively describe the sensitivity of Electron
Density Perturbations (EDPs) recorded by the DEMETER satellite to global earthquakes with 𝑀𝑀 ≥4.8.
Results show that the EDPs are significantly related to global medium-to-strong earthquakes and that optimal
parameters for removing EDPs which are non-related to earthquakes and the optimal time-space windows forcorrelating earthquakes and EDPs are variable in space. Moreover, our results show that the intensity of EDPs
makes little contribution to distinguishing the perturbations related to earthquakes with different magnitudes
and perturbations non-related to earthquakes, while the 𝐾𝐾𝑝𝑝 index is effective for improving the Signal/Noiseratio of our model, where Signal/Noise refers to the EDPs related/non-related to earthquakes. Finally, using
the optimal time-space windows for correlating EDPs and earthquake, we construct several earthquake
prediction models and quantitatively evaluate their power. We find that these EDP-based earthquake
predictions are better than the spatially variable Poisson model showing the great potential of predicting
earthquakes based on satellite-based Earth observation techniques. However, the spatio-temporal accuracy ofthese models for predicting earthquakes is not satisfactory, as the alerted time-space volume is big.

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Characteristics of Geomagnetic and Pre-Seismic Changes
in Ionospheric Electron Density over Japan Area
Hattori, K. (1)(2)(3), Song, R.(1), Yoshino, C. (1), and Liu, J-Y.(4)(1) Graduate School of Science, Chiba University, Japan(2) Center for Environmental Remote Sensing, Chiba University, Japan(3) Research Institute of Disaster Medicine, Chiba University, Japan(4) National Central University, Taiwan

Pre-seismic electron density anomalies have been a widely discussed phenomena in ionosphericstudies. However, it is not well-known what causes these anomalies and what is the possible source
mechanism. These are still having not been elucidated questions and more investigations are needed to makeclear that phenomena.
On the other hand, the another natural question is how to distinguish ionospheric anomalies fromother disturbances such as geomagnetic storms. In many cases, simultaneous geomagnetic activities makeit difficult to detect an earthquake precursor effect in the ionosphere. To overcome this problem, acharacterization and classification of magnetic storm and earthquake signatures is necessary. For thispurposes, in this study, we mainly focused on similar and differing effects of magnetic storms and earthquake
preparation period on the ionospheric composition.
In this study, the time period after magnetic storms and before earthquakes were investigated. The
selection of earthquake cases was carried out between 1998 to 2013 with M>6 and depth<30 km. Under thesecriteria, 53 earthquakes were extracted. To determine the anomalous behaviour before each, we examined
the TEC responses against each earthquake both in temporal and spatial ways by using GIM TEC data.
Thus, we found that 28 earthquakes had caused anomalous condition in the ionosphere. We further
examined these earthquake cases with tomography method to investigate their 3D distribution andencountered with that 13 of those had also shown similar anomalous behaviour. Meanwhile, magnetic
storms were also selected between 1998 to 2013 within the intense storm category in which Dst < -100 nT.
The onset time was in daytime hours from 06:00 AM to 06:00 PM. Hereby, 42 geomagnetic storms wereobtained. Among these, we have chosen arbitrarily 10 different magnetic storm case days and same analysis
steps for earthquakes was followed again to determine the anomalous changes of ionospheric electron content.
The TEC data sets were extracted from both local receivers (GPS-TEC) and global receivers (GIMTEC). In tomography process, GPS-TEC data was inverted to the electron density (Ne) quantities by using
Neural Network non-linear function approximation method. This process was carried out for eachionospheric sample point (altitude) to examine 3D electron density distribution in the ionosphere. On theother hand, since TEC is usually slower to respond the compositional changes in the ionosphere, ionosphericfoEs and NmF2 parameters which are obtained from ionosondes were also employed as complementary data.
There, the time series plots of these parameters were prepared. For pre-seismic period, ionospheric NmF2
had mainly shown an enhancing characteristic even at night time, while for the storm cases, fluctuation wasusual response after around few hours of storm onset time. Besides that, foEs values have found as changed
suddenly over stations near the epicentre, however, for the storms foEs responses were irregular and was
not so distinctive. The hmF2 values have increased, while before earthquakes it was not as much as affected.
Moreover, the another observed difference was disturbance characteristic that after magnetic storms theionosphere has been disturbed both negatively and positively, while before earthquakes positive disturbancesand quiet weak negative disturbances were usually effective around the epicentre.

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Abstracts of poster presentations

46

IWEP7
Current status of the Prelude: Precursory electric field observation cubesat demonstrator

Masashi Kamogawa (Univ. of Shizuoka), Masahiko Yamazaki (Nihon Univ.)
Tetsuya Kodama (JAXA),

Abstract

Small satellites have already been used for earthquake precursory phenomena observation in other countries,
but CubeSat-class satellite has not existed yet. The French seismo-electromagnetic satellite DEMETER
reported statistically the reduction of the radio wave intensity 4 hours before earthquakes, but its mechanismand dependence on local time is unknown.

The 6U CubeSat "Prelude" under development is aimed at verifying the reduction of radio wave intensity 4hours before earthquakes by installing only one pair of electric field probes which is already proven by
DEMETER in the vertical direction, constructing the satellite constellation in a low cost.

In February 2023, a probable earthquake prediction demonstration CubeSat based on the detection of preearthquake phenomena, was additionally selected for the "Innovative Satellite Technology Demonstration
Unit 4 theme open call".

The Innovative Satellite Technology Demonstration Unit 4 is scheduled to launch in 2024.

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Study of Atmospheric Precursor Anomalies Associated with Earthquake Events:
Role of Machine Learning
Vijay Subhash Katta1, Vinod Kumar Kushwah2, Gourav Srivastava3
1. School of Advanced Computing, SAGE University, Bhopal (M.P.) India
2. Department of Physics, Hindustan College of Science & Technology, Farah, Mathura-281122 (U.P.) India
3. School of Advanced Computing, SAGE University, Bhopal (M.P.) India
Email: kushwahvk2000@gmail.com

Abstract
Prior to an earthquake, physical and chemical interactions in the earth's crust may induce abnormalities inlatent heat flux, air and surface temperature. As the energy accumulated in rocks is released, earthquakes occur.
Sometimes, ground movements generate rifts in the earth's surface, and occasionally, two sides of an existingfault shift towards one another.
Several remote sensing techniques, such as satellites and various ground-based instruments, are used to detect
the increases in latent heat; It record the surface air temperature, the surface latent heat flux, the relative
humidity, and other atmospheric variables. In order to explore the phenomenon of earthquake precursors, we
utilized satellite data for an atmospheric component known as surface latent heat flow. Here, it is determined
if there is a relationship between the atypical behavior of surface latent heat flux and the devastating
earthquakes that occurred west of Kathmandu, Nepal, on January 24, 2023, with a magnitude of 5.6, and on
the Turky-Seria Border on February 6, 2023, with a magnitude of 7.7, causing significant loss of life andproperty. Seismicity is induced by the release of energy in fault zones hundreds of kilometers wide in a
structurally complex and inhomogeneous collision region such as the Anatolian Plate, where the East
Anatolian Fault and Transform Fault are located. To the south and southwest is the African Plate. In addition,
the Eurasian Plate is located in the north of Turkey. These plates revolve in a counter-clockwise manner.
Keywords: Latent Surface Temperature, Radon emissions, low frequency emissions, earthquakes, solar flares, magnetic
storms, precursors etc.

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Continuous radon measurement in atmosphere at Okayama and Kiyosumi
Kiyotaka Ninagawa1, Tohru Okabayashi2, Yuichiro Ohta3, Chie Yoshino3,Katsumi Hattori3, Nobuhiro
Maeda
1Japan Geochronology Network, NPO

2Department of Medical Risk and Crisis Management, Faculty of Risk and Crisis Management,

Chiba Institute of Science.

3Graduate school of Science, Chiba University

Abstract.
We designed radon detection system utilizing a PIN photodiode, as known as a high sensitive alpha ray
detector in Super Kamiokande, and conducted to measure the radon concentration in atmosphere. Our
system consists of a Si PIN photodiode (S3204-09, unsealed, Hamamatsu Photonics K.K.), aluminum pot as
an atmosphere accumulator, a charge amplifier (H4083, Hamamatsu), a high voltage power supply module(C4900-01, Hamamatsu), a pulse shaped amplifier with time constant of 10 ms, a multi channel analyzer(MCA-LiteN), and a PC for data acquisition. We found the four components of alpha ray originated from 218Po,
214Po and 210Po of U series, and 212Po of Th series, respectively.
We measured the radon concentration in atmosphere at domestic two measurement points at Okayama
since 2022 and Kiyosumi since 2017, respectively. This time we investigated inhalation height dependenceof air, and the relations between radon variation and weather (typhoon and precipitation). We tried to findrelations between radon variation and nearby earthquakes. We also report some troubles, motor stop andsudden rise of radon intensity in observing radon variation.
We thank to Akitsugu Kitade, Kazuhide Nemoto, Haruna Kojima and Jyunpei Ohmura of Graduate
school of Science, Chiba University for data collection at Kiyosumi.

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Relationship between catfish activities and geophysical changes.
(a preliminary report)
Yoichi Noda1, Katsumi Hattori 2,3,4, Toshiyasu Nagao 5, Chie Yoshino 2
1. Graduate School of Science and Engineering, Chiba University, Japan
2. Graduate School of Science, Chiba University, Japan
3. Center for Environmental Remote Sensing, Chiba University, Japan
4. Research Institute of Disaster Medicine, Chiba University, Japan
5. Institute of Oceanic Research and Development, Tokai University, JapanThe macroscopic anomaly associated with earthquakes is the natural unusual phenomenon that can be noticed without
scientific instruments but by a naked eye or by an ordinary human sense, such as land deformation, rumbling, unusual
behavior of wild animals, natural lightening, and so on. There have been a number of reports on such phenomena fromall over the world. However, sufficient scientific research is not going on them. In this study, we deal with the behaviors
of a catfish for the research target, because a lot of reports on them have been published in the past as related withseismic events. There is required to be more research based on comprehensive zoological aspects such as animal
behavior, ecology, physiology, psychology, and so on. The relationship between physical and chemical changes inearthquake precursor phenomena and the susceptibility of animals requires to be clarified. Therefore, we developed amethod to quantify catfish behavior using a special aquarium and CCD camera system. Secondly, Catfish behavior wasclassified as a behavior pattern composed of four elements: swimming trajectory, swimming time, swimming distance,
and average swimming speed. As a result, we succeeded in comparing changes between detailed behavioral
information and geophysical changes. We introduce very preliminary results of our observation and consider the future
directions of the current work.

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Physical mechanisms of induced and triggered seismicity:
An implication for electromagnetic triggering of earthquakes
Victor Novikov1,2, Dmitry Kulkov2, Stanislav Parov2
1

Joint Institute for High Temperatures, Russian Academy of Sciences, 125412 Moscow, Russia
2
Research Station at Bishkek, Russian Academy of Sciences, Bishkek, Kyrgyzstan, 720049

Abstract
A new type of earthquake triggering has been discovered during the field experiments on electromagnetic
monitoring of the Earth crust resistance at the Pamir and Northern Tien-Shan regions where DC current of
0.6-3.5 kA has been injected into the crust through the grounded dipole of 4.2 km length. The spatiotemporalvariation of regional seismicity just after the DC current injection has been found, that may be explained bytriggering of weak earthquakes around the dipole due to interaction of electromagnetic field with stressed rocks[1]. The observed field data were confirmed in laboratory experiments at the press and shear machines, when
it was demonstrated that DC current injection into the tested rock sample is resulted in sharp increase of
acoustic emission (crack formation) followed by the sample failure, as well as in triggering of laboratory"earthquakes" at the spring-block models of seismogenic fault. Nevertheless, the mechanism ofelectromagnetic earthquake triggering is still poorly understood that prevents the practical application ofobtained results to earthquake hazard mitigation based on earthquake control or short-term prediction.
In this connection we analyze various physical mechanisms of well-studied cases of induced and triggered
seismicity for their possible application to explain the electromagnetic phenomena of earthquake triggering.
As a possible candidate of a mechanism of electromagnetic/electric triggering of earthquakes we consider theJoule heating of porous fluid-saturated rocks during DC current flow through the rocks resulted in increase of
fluid pore pressure and corresponding decrease of efficient rock strength followed by a rupture of the fault
when it is in subcritical strain-stress state. For verification of this hypothesis, we carried out the laboratory
experiments at the specialized press, where the increase of the sample deformation rate is observed during
electrical processing of the sample. The experimental results are compared with numerical data calculated by
COMSOL Multiphysics© software, which indicate the clear pore pressure increase due to DC current impact.
This work was supported by the Ministry of Science and Higher Education of the Russian Federation (State
Assignments No. 075-01129-23-00 and No. 122101000008-9).
References:
1. Zeigarnik, V.A., Bogomolov, L.M. & Novikov, V.A. Electromagnetic Earthquake Triggering: Field
Observations, Laboratory Experiments, and Physical Mechanisms - A Review. Izv., Phys. Solid Earth 58, 30–
58 (2022). https://doi.org/10.1134/S1069351322010104.
2. Kang, JQ., Zhu, JB. & Zhao, J. A review of mechanisms of induced earthquakes: from a view of rockmechanics. Geomech. Geophys. Geo-energ. Geo-resour. 5, 171–196 (2019). https://doi.org/10.1007/s40948018-00102-z.
3. Gomberg, J., Johnson, P. Dynamic triggering of earthquakes. Nature 437, 830 (2005).
https://doi.org/10.1038/437830a.

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Studies of seismo-electromagnetic and seismo-ionospheric effects at
Kamchatka
Vyacheslav Pilipenko
Institute of Physics of the Earth (Moscow) pilipenko_va@mail.ru
Danila Chebrov
Kamchatka Branch of Geophysical Survey (Petropavlovsk-Kamchatsky) danila@emsd.ru
According to the threat of natural disasters, Kamchatka is one of the most dangerous regions of
the world. Only during the lifetime of the current generation, many strongest earthquakes with
M=6.6-9.1 occurred in this region. There is no doubt that natural disasters in Kamchatka willcontinue to occur with a high frequency. The Geophysical Survey of the Russian Academy of
Sciences operates >40 years on the territory of Kamchatka (http://www.emsd.ru). The system ofreal-time observations includes: 80 seismic stations; 27 stations for measuring deformations of theearth's crust using GPS receivers; 13 wells and bore-holes equipped with automatic systems forrecording pressure, temperature, electrical conductivity of groundwater; 6 sites for registration of
subsoil gases and meteorological parameters; 6 points for measuring the atmospheric electric field;
amplitude-phase characteristics of VLF signals from 10 radiopaths; and 2 stations ofelectromagnetic observations. By the breadth and complexity of geophysical observations in aseismically active region, the Kamchatka testing ground is one of the leading in the world. Work at
the testing ground is carried out by seismologists, specialists in hydrogeochemistry and fluid
dynamics, experts in radioactive emanations, atmospheric electricity, atmospheric and ionosphericphysics, and electromagnetic ULF-ELF emissions. In addition, leading researchers of the Instituteof Physics of the Earth (https://ifz.ru/) are involved in the work. This allows one to set thefundamental problems of the physics of the lithosphere-atmosphere-ionosphere interactions duringcatastrophic events using data from this international prognostic testing ground. A synergistic
approach is used, including both theoretical modeling and analysis of long-term multi-instrumental
observational data. There are not so many places in the world where forecasting polygons are
deployed. But no matter how well these polygons are equipped, there are no guarantees that theseobservations will enable us to assess the reliability of forecasting methods in the foreseeable future
because no one can guess where and when a seismic event will occur. In this talk we present a
brief review of recent observational and theoretical results obtained at Kamchatka testing ground.

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Criticality analysis of the VLF recordings prior to two strong earthquakes that
happened in central Greece on March of 2021
Dimitrios Z. Politis1, Stelios M. Potirakis1,2, *, Yiannis F. Contoyiannis1, Sudipta Sasmal3, Shih-Sian Yang4,
and Masashi Hayakawa5,6
1

Department of Electrical and Electronics Engineering, Ancient Olive Grove Campus, University of West Attica, GR-12244 Egaleo,

2Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory of Athens, Metaxa and Vasileos

GreecePavlou, Penteli, GR-15236 Athens, Greece
3

Institute of Astronomy, Space and Earth Science, AJ 316, Sector II, Salt Lake, Kolkata 700091, India

4

Department of Space Science and Engineering, National Central University, Jhongli, Taoyuan 320317, Taiwan

5

Hayakawa Institute of Seismo Electromagnetics, Co., Ltd., UEC Alliance Center, Chofu 11, Tokyo 182-0026, Japan

6

Advanced Wireless Communication Research Center, University of Electro-Communications (UEC), 1-5-1 Chofugaoka, Chofu,
Tokyo 182-8585, Japan* spoti@uniwa.gr

Abstract
In this paper we investigate two strong earthquakes (EQs) which sequentially occurred on 3 and 4 March of2021 in Central Greece, the epicenters of which were located on land [M6.3 occurred on 3 March 2021,
10:16:09 (UT), depth 8.0 km, at (39.755°N, 22.176°E), and M5.8 occurred on 4 March 2021, 18:38:19 (UT),
depth 10.0 km, at (39.787°N, 22.116°E)]. We present the criticality analysis of the very low frequency (VLF)
subionospheric propagation data acquired by a recently installed VLF receiver which is located at the
University of West Attica in Athens (Greece). Specifically, we applied the method of critical fluctuations (MCF)
analysis to the raw nighttime amplitude recordings from multiple transmitters, detecting power-law behavior
for the laminar lengths’ distributions of specific time windows recorded prior to each of the abovementioned
EQs, with power law exponent values that imply criticality. Further analysis of the specific time windows,
with the use of the autocorrelation function (ACF), proved that these time windows are also characterized byhigh ACF values persisting for long time. Our findings reveal that the ionosphere was indeed in critical state
before each of the studied EQs.

53

IWEP7The Response of Geomagnetic Daily Variation and Ionospheric Currents to the
Annular Solar Eclipse on 21 June 2020
*Xiaocan Liu1, Junjie Chen2,4, Peng Han3, Jiuhou Lei2
1. Institute of geophysics China Earthquake Administrition, Beijing, China,
2. School of Earth and Space Sciences, CAS Key Laboratory of Geospace Environment, University of Science and Technology of China, Hefei, China,
3. Department of Earth and Space Sciences, Southern University of Science and Technology, Shenzhen, China,
4. Department of Earth Sciences, University of Hongkong, Hongkong, China

According to the ampere's law, the geomagnetic variations caused by the ionosphere current can detect the ionosphere
electrodynamic process during a solar eclipse. Due to the lack of observation, the previous research on the geomagnetic
effect of solar eclipse focused on the range of one or several geomagnetic stations, which makes the latitude and local
variation characteristics of the geomagnetic effect and the corresponding ionosphere electrodynamics process are nottotally studied. The annular solar eclipse on June 21,2020 passed through China during the daytime, and the regional
high density observation of the Geomagnetic Network Center of China, Institute of Geophysics, China Earthquake
Administration and International Real-time Magnetic Observatory Network provides a good opportunity for the studyof this issue.
In this work, we studied the latitude and local time dependences of the geomagnetic-solar eclipse effect of the June
21,2020 annular eclipse event in China and the neighbour areas, and analyzed the electrodynamics process of theionosphere. The results are as follows:
1. The eclipse weakens the intensity of three components for the geomagnetic daily variations. Amongthem, the effectof the north-south component ΔX has a clear latitude dependence, that is, the decrease of intensity significantly
below the center of the Sq current vortex and is slightly weaker above the focus, while the eclipse effect of ΔX near
the center of the current vortex is almost absent. In addition, the effect of the east-west component ΔY increases aslatitude decreases and the eclipse obscuration rate increases .
2. The eclipse effect of ΔY along the totality from noon to afternoon shows a local time dependent, whilethe eclipse
effect of ΔX component is not so regular like ΔY, it is roughly stronger from early afternoon to early afternoon thanthat in the late afternoon. The eclipse effect of the vertical component ΔZ was weak, mainly in the early afternoon
period on the totality path.
3. The eclipse effects of the geomagnetic daily variation simulated by the TIEGCM are generally consistentwith those by
the ground magnetometer data. It was demonstrated that the ionospheric current system caused by the eclipse hasa counter-Sq pattern and thus weakens the background Sq current system.
Keywords: Geomagnetic Daily Variation, Ionospheric Currents, Solar Eclipse
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Multi-sensor monitoring network for earthquake precursor study
near subduction zone at Boso, Japan
Chie Yoshino1, Katsumi Hattori1,2,3, Rui Song1, Toru Mogi4, Tada-nori Goto5, Ichi Takumi6, Hiroshi Yasukawa7, Motoaki
Mouri8, Jun Izutsu9, Chihiro Yamanaka10, Masashi Kamogawa11, Yoshiaki Ando12, Shunji Kotsuki13,2, Jiancang Zhuang14, Eizo
Hideshima6, Koji Suzuki15,16, Takeshi Morimoto17, Yukio Fujinawa18, Peng Han19, Jann-Yenq Liu20, Dimitar Ouzounov21,
Valery Tramutoli22, Nicola Genzano22, and Qinghua Huang23
Graduate School of Science, Chiba University, 2. Center for Environmental Remote Sensing, Chiba University, 3. ResearchInstitute of Disaster Medicine, Chiba University, 4. Hokkaido University, 5. University of Hyogo, 6. Nagoya Institute ofTechnology, 7. Aichi Prefectural University, 8. Aichi University, 9. Chubu University, 10. Osaka University, 11. University of
Shizuoka, 12.The University of Electro-Communications, 13. Institute for Advanced Academic Research (IAAR), Chiba
University, 14. Institute of Statistical Mathematics, 15. Kobe University, 16. Asian Disaster Reduction Center (ADRC), 17. Kindai
University, 18. Organization for Development of Resilient Communities (ODRC), 19. Southern University of Science andTechnology, China, 20. National Central University, Taiwan, 21. Chapman University, USA, 22. University of Basilicagta, Italy, 23.
Peking University, China
1.

New observations from ground and space have provided multiple evidences of pre-earthquake signals and the latest
studies show their statistical significance, repeatability, and universality. In this project, to understand the preparation
process of large earthquakes and slow-slip events in subduction zone, especially to clarify the nucleation stage of theearthquake cycle, we plan to establish a dense observation network in Boso, Japan, where large subduction earthquakes
are expected soon. Since the subsurface fluid flow may play an important role in the preparation process of subduction
activities, we intend to employ electromagnetic approaches including oceanic and continental MT survey to monitor theunderground resistivity structure which is sensitive to the dynamics of fluid. Other geophysical monitoring such as ULF
geomagnetic and geoelectrical observations, radon measurements, and inland GPS movements, TIR, and OLR will beincorporated to help to understand the preparation process and evaluate the applicability of various pre-earthquake signals
towards short term earthquake forecasting. We call this idea “sensor WEB”. We will show the state of the art and someresults in our presentation.
This study was supported by Grand-in-Aids for Scientific Research of Japan Society for Promotion of Science(26249060).

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ROC Analyses to Assess Pre-earthquake Information in Ionospheric Electron Density
Data Observed by Ionosonde, at Kokubunji, Japan
Katsumi Hattori1,2,3, Shunya Mitsuishi4, Rui Song1, Chie Yoshino1, and Jann-Yenq LIU5
1. Graduate School of Science, Chiba University, Japan
2. Center for Environmental Remote Sensing, Chiba University, Japan
3. Research Institute of Disaster Medicine, Chiba University, Japan
4. Department of Earth Sciences, Faculty of Science, Chiba University, Japan
5. National Central University, Taiwan

Recently, ionospheric anomalies related to earthquakes have been reported and are considered promising for short-term
earthquake forecast. In Japan region, the previous statistical studies on GNSS-TEC and Ionosonde show a statisticallysignificant correlation between sizable earthquake and TEC anomaly about 0-5 days before the earthquake. Similarly,
regarding the NmF2 by ionosonde, there is a significant correlation between them on 1-10 days before the earthquakes
with M<6, depth D<40 km, epicenter distance R<350 km. Here, NmF2 indicates the maximum electron density in
Ionosphere.
In this paper, we assess the effectiveness in short-term earthquake forecast using the NmF2 data during 1958-2019. In
this study, we used ionosonde data observed at Kokubunji (35.71N, 139.49N), Japan, operated by the National Instituteof Information and Communications Technology (NICT).
We defined the anomaly of NmF2 as the value in excess of 15 days backward median + 1.5 IQR of the NmF2 at thesame time hour in the previous 15 days. And we define the anomalous day as ten or more hours of the anomalies appear
in one day.
Then, we performed Molchan’s Error Diagram (MED) analysis to evaluate the efficiency of NmF2 anomalies forearthquake forecasting. MED analysis is very similar to ROC (receivers operation characteristic curve) approach. The
MED results show that NmF2 anomalies contains a precursor information and the tendency is clearer for the shallower,
the larger, and the closer earthquakes. Using MED analysis, we can estimate the optimum parameters of earthquake
detection; lead time T, alarm window L, earthquake magnitude, hypocenter depth, epocentral distance from the ionosonde.
The result indicated that the forecast is most efficient when M>6.4, D<20 km, R<200 km, T=10, L=1.Using theseparameters, it is found that about 46% of targeted earthquakes can be successfully detected.

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Soil radon concentration analysis by multi-channel singular spectrum
Katsumi Hattori1,2,3, Kazuhide Nemoto4, Haruna Kojima5, Akitsugu Kitade5,
Shu Kaneko5, Yuichiro Ota5, Chie Yoshino1, Toru Mogi1, and Dimitar Ouzounov6
1. Graduate School of Science, Chiba University, Japan
2. Center for Environmental Remote Sensing, Chiba University, Japan
3. Research Institute of Disaster Medicine, Chiba University, Japan
4. Department of Earth Sciences, Faculty of Science, Chiba University, Japan
5. Graduate School of Science and Engineering, Chiba University, Japan
6. Chapman University, USA

Recently, there are many papers on electromagnetic pre-earthquake phenomena such as geomagnetic, ionospheric, andatmospheric anomalous changes. Ionospheric anomaly preceding large earthquakes is one of the most promisingphenomena. Lithosphere-Atmosphere-Ionosphere Coupling (LAIC) model has been proposed to explain these
phenomena. In this study, to evaluate the possibility of chemical channel of LAIC by observation, we are developing soil
and atmospheric Rn observations using an α-ray detector in Chiba-Ibaraki area to investigate the relationship between
earthquakes and Rn emissions from the ground. We have installed sensors for atmospheric electric field, atmospheric ion
concentration, atmospheric Rn concentration, soil radon Rn concentration (SRC), and weather elements, Since theatmospheric electricity parameters are very much influenced by weather factors, it is necessary to remove these effects asmuch as possible. In this aim, we apply the MSSA (Multi-channel Singular Spectral Analysis) to remove these influencesfrom the variation of SRC and estimate the soil Rn flux (SRF). We investigated the correlations (1) between SRF andprecipitation and (2) between SRF and the local seismic activity around Asahi station. The preliminary results show that
SRF was significantly increased by heavy precipitations of 20 mm or more in total for 2 hours. We proposed two typesof models, a rainwater load model and a rainwater infiltration model, and it is appropriate for both models to work and(2) between SRF and local seismicity within an epicenter distance of 50 km from the station.

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IWEP7A development of signal discrimination method using Multi-channel Singular Spectrum
Analysis (MSSA) for ULF band electromagnetic data, in Boso, Japan
Shu Kaneko1, Toru Mogi2, Chie Yoshino2, Katsumi Hattori2,3,4
1. Graduate school of Science and Engineering, Chiba University, Japan
2. Graduate school of Science Chiba University, Japan
3. Center for Environmental Remote Sensing, Chiba University, Japan
4. Disaster Medicine Research Institute, Chiba University, JapanAn electromagnetic phenomenon associated with crustal activity in the ULF band (f < 10 Hz) is expected
as a method that can detect the signal directly from the intra-crust or plate boundary. However, the observed
signal includes not only the earthquake-related signal but also the solar-origin signal and artificial noise,such as the leak current from the DC-driven train. Detection of the signal is difficult because the amplitudeof the earthquake-related signal is tiny compared with the other noises, and the waveform of the signal issimilar to the artificial noise. Recent analyses were performed in a noiseless environment, such as the region
far from the city area, and at night-time to escape this problem. However, by this scheme, we miss detecting
the signal that occurs in the daytime. The new signal discrimination method is essential to increase thechance of detecting the signal in the daytime.
We are developing a new signal discrimination method based on Multi-channel Singular Spectrum
Analysis (MSSA) to overcome this problem. MSSA is the extension of Singular Spectrum Analysis (SSA),
resulting in MSSA can decompose multiple time series to several principal components (PCs). Then, choosing
and summing arbitrary PCs with some threshold, such as correlation and contribution ratio of the PCs, thetime series can be discriminated into the signal and noise parts.
In the MSSA-based signal discrimination method developed in this study, remove solar-origin signals from
7ch data (target site 5 components (horizontal magnetic field 2ch (Hx and Hy), vertical magnetic field 1ch(Hz), and horizontal electric field 2ch (Ex and Ey)) and reference site 2ch (magnetic field 2ch (Rx and Ry))),then, obtain a local signal. After applying this method to actual data acquired on the Boso Peninsula forsignals with a period of less than 400 s, the solar-origin signal was removed, and a local signal of about 1 nT
for the magnetic field and about 2 mV/km for the electric field was detected. This presentation will focus on
the performance and effectiveness of the method.

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A Study of the ULF seismo-magnetic phenomena in Kakioka, Japan,
during 2015-2020*Wenchao Li1, Shu Kaneko1, Chie Yoshino2, Katsumi Hattori2，3，4

1. Graduate School of Science and Engineering, Chiba University, Japan
2. Graduate School of Science, Chiba University, Japan
3. Center for Environmental Remote Sensing, Chiba University, Japan
4. Research Institute of Disaster Medicine, Chiba University, Japan

Abstract:
To mitigate earthquake disasters, the establishment of the short-term earthquake forecast technique isimportant. To achieve this, the ultra-low frequency (ULF) geomagnetic field changes has been studied andstatistical significance in correlation and precursor characteristics in ROC analysis have been presented, Itmeans that the ULF geomagnetic measurement has a potential parameter for the short-term earthquake
forecast. In previous studies, the data observed Kakioka station during 2001-2010 operated by JMA has beenutilized. In order to clarify ULF seismo-magnetic phenomena, we have studied the geomagnetic data observedat the Kakioka (KAK) station, Kanto, Japan, during 2015-2020. The magnetic data and earthquake catalogs
obtained from Japan Meteorological Agency. The same approach with the previous studies have been
performed, To select earthquakes, we use the Es parameter which considers the magnitude and distance of anearthquake simultaneously to select statistical samples. As the frequency of original geomagnetic data is 1Hz,the method of wavelet transform was implemented, and extract the signals at the frequency around 0.01Hz.
Ground-based ULF geomagnetic data are a superposition of several signals: global magnetic perturbations,artificial noises, and magnetic signals possibly due to underground activities. To minimize artificial noises, weselected the midnight time data (JST 1:30-3:30). And to reduce the influence of global magnetic perturbations,the station Kanoya (KNY) was chosen as reference station. Then the statistical method of superposed epoch
analysis (SEA) was adopted to highlight the weak but significant signal from noisy data. Finally, to verify theusefulness of the prediction model compared with random prediction. We evaluated the precursory
information of ULF geomagnetic signals for local sizable earthquakes using statistical method receiver
operating characteristic (ROC) curve. In ROC curve, the closer to the upper left corner, the better performing
for this prediction model.
Keywords: ULF electromagnetic phenomena, Superposed Epoch Analysis(SEA), Molchan's Error Diagram

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IWEP7Development of an LF-band broadband interferometer to identify LF-band signals
related to earthquakes
Yuichiro Ota1, Kenshin Miura2, Chie Yoshino 3, Katsumi Hattori 3,4,5, Noriyuki Imazumi6
1. Graduate School of Science and Engineering, Chiba University, Japan
2. Faculty of Science, Chiba University, Japan
3. Graduate School of Science, Chiba University, Japan
4. Center for Environmental Remote Sensing, Chiba University, Japan
5. Research Institute of Disaster Medicine, Chiba University, Japan
6. The Institution of Professional Engineers, Chiba Branch, Japan

Recently, there have been reports of earthquake precursor phenomena related to the LF band. To develop an LF-band
broadband interferometer capable of spatio-temporal estimation of LF-band electromagnetic wave sources, we started
LF-band electromagnetic wave observations using interferometer elements on the rooftop of Chiba University. First, we
conducted a waveform and pulse count survey using one interferometer element and detected an increased number ofpulses before the earthquake which is unlikely to be caused by cloud to ground discharge and typical waveforms during
the time. We also evaluated the performance of three interferometer elements as an interferometer system and found thatthe synchronization system needs to be improved.

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Study on Volcanic Activity of Mt. Shinmoedake in 2018 Using Himawari AHI Data
Akitsugu Kitade1, Shu Kaneko1, Chie Yoshino2, and Katumi Hattori2,3,4
1. Graduate School of Science and Engineering, Chiba University, Japan
2. Graduate School of Science, Chiba University, Japan

3. Center for Environmental Remote Sensing, Chiba University, Japan
4. Research Institute of Disaster Medicine, Chiba University, Japan

Ground-based volcano monitoring is not possible for all active volcanoes due to topographical restrictions
and cost. On the other hand, volcanic activities that cause lava eruptions or eruptions that cause significant
human and economic damage are usually accompanied by an increase in surface temperature, making satellite
remote sensing effective for temperature monitoring. Therefore, we have been developing algorithms todetect temperature anomalies associated with volcanic activities (especially for monitoring lava activities thatcause serious damage to human lives and predicting pyroclastic flows) by spatiotemporal analysis of groundsurface temperature around volcanoes using thermal infrared nighttime data on board artificial satellites. As aresult, Noguchi et al. (2004) demonstrated the effectiveness of monitoring volcanic activity in the tropics1
using nighttime infrared data from the MODIS sensor onboard the Aqua/Terra satellites, and Tsutsumi et al.
(2020) showed that the appearance of a lava dome on the 2011 eruption of Mt.shinmoe In a similar analysis
to Tsutsumi et al. (2020) for the eruptive activity of Mt. Shinmoe in 2018, an anomalous rise in surface
temperature associated with the appearance of a lava dome was detected, but the anomalous rise in surface
temperature was not detected visually or by SAR data. The reason for this may be that the summit area wascovered by clouds at the time of the satellite observations, which prevented observation of the ground surface.
There are two possible means of measuring surface temperatures in consideration of cloud effects: using
satellite-observed microwave data and increasing the frequency of observations at target locations using
geostationary meteorological data to increase the number of cloud-free observations. The former is promising,
but requires a large footprint, since microwaves can penetrate clouds. The latter is promising, but the footprint
becomes large. The latter is affected by clouds, but the observation frequency is every 10 minutes (2.5 minutes
near Japan) (in the case of Himawari No. 8-9).
Therefore, by using thermal infrared data from the Himawari-8 satellite, which has a higher temporal
resolution, we conducted a research study to contribute to the detection of surface temperature anomalies
associated with magma eruptions and the appearance of lava domes, and to their detection as early as possible.
As a result, we were able to confirm the temperature anomaly several hours before the eruption occurred.

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Characteristics of Spatio-Temporal variation of b-values
with statistical assessment and GNSS-based strain :Application to the 2016 Kumamoto and the 2011 Tohoku earthquake
Katsumi Hattori1,2,3, Zhong Yi4, and Chie Yoshino1
1. Graduate School of Science, Chiba University, Japan
2. Center for Environmental Remote Sensing, Chiba University, Japan
3. Research Institute of Disaster Medicine, Chiba University, Japan
4. Graduate School of Science and Engineering, Chiba University, JapanThe frequency-magnitude distribution of earthquakes is expressed by the Gutenberg-Richter Law, in which a criticalparameter is the b-value. The results of previous studies show that the b-value portrays not only the quantitation
relationship between different earthquakes but also its magnitude negatively correlates with the regional stress level. In
particular, the b-values show apparent precursor anomalies before some large earthquakes. But objectively judging theirrelevance to earthquakes is difficult. In order overcome this, we are developing evaluation methods that introduced the
Akaike information criterion (AIC) and GNSS-based strain. Regarding the former, AIC, we investigate the differencedAIC between AIC over reference period and that of studied period. For the latter, GNSS-based strain, the correlation
between monitoring strain anomalies and major local earthquakes has been verified in recent years.
Therefore, this paper analyzes the characteristics of the b-value and GNSS-based strain network related to the 2016
Kumamoto and the 2011 Tohoku earthquakes to examine whether there are any anomalies in the occurrence of large
earthquakes. The results will be shown in the presentation.

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