1. Earthquake Prediction Research Center, Tokai University
Combined approach using the electromagnetic precursory phenomena and critical phenomena for a short-term earthquake prediction
Tokyo
We are
here!
Nagoya
Earthquake Prediction Research Center, Tokai University
Toshiyasu NAGAO

2. Today’s talk What is “Seismo-Electromagnetics”
some examples (California and Japan)
Greek VAN method
Introduction of Natural Time analysis
Introduction of LAI (Lithosphere-Atmosphere and Ionosphere) coupling

3. What is “Seismo-Electromagnetics”
Research for electromagnetic phenomena possibly associated with (impending) earthquakes.
It has a long history, however the existence of the phenomena themselves still have a lot of arguments.
Best-known example is the case of the M7.1 Loma Prieta (California) EQ in 1989 (Fraser-Smith et al., 1990)
However………
　We know that
　　－＞　EM phenomena preceded by EQs are so small !

4. M7.1 Loma Prieta (California) EQ in 1989

5. Seismo-Electromagnetics in Japan
100Ｍ
10Ｍ 1Ｍ
100ｋ
10ｋ 1ｋ
100 10 1
0.1 ＤＣ
（Ｈｚ）
Method and Frequency range
Seismo-Electromagnetics
in Japan
telluric current
3-comp. magnetic
ＵＬＦ
Brown letters
Signals emitted from the lithosphere
Narrow band 3-comp. magnetic
ＥＬＦ
Blue letters　
Ionosphere/troposphere
anomaly
　(radio wave transmission
anomaly)
2-comp. magnetic for direction
finding
EM pulse measurements in a
borehole
ＶＬＦ
Anomalous transmission of radio
waves ＬＦ
ULF to VHF
Vertical E-field
measurements in a borehole ＭＦ ＨＦ
FM broadcast wave anomalous
transmission
ＶＨＦ
Natural noise observation
Micro wave observation

6. Nagao et al., 2002
(J. Geodynamics)

7. Seismo-Electromagnetic studies in Japan
Signals emitted from the lithosphere
DC telluric current (Tokai, Hokkaido, Tokyo, Chiba Univs.)
ULF 3-comp. magnetic (Tokai, Chiba, ECU, Hokkaido, Chubu Univs.)
ELF narrow band 3-comp. magnetic (Chubu, Naoya Tech. Univs.)
VLF on-land magnetic direction finding (Tokai Univ.)
VLF borehole electromagnetic pulses (Kyoto Sangyo Univ.)
Broad band (VLF-VHF) electromagnetic field (Osaka Univ.)
Micro wave (JAXA, Chiba Univ.)
Ionosphere/troposphere anomaly
VLF-LF radio wave anomalous transmission (ECU, Chubu Univ.)
GPS-TEC anomaly (Chiba, Tokyo Gakugei, ECU Univs.)
VHF FM radio wave anomalous transmission (Hokkaido, Tokyo Gakugei, Tokai
Chiba Univs., ECU, Okayama Univ. of Science)
Atmospheric electric field (Tokyo Gakugei, Waseda Univs.)
Underground Electric field (Akita Pref. Univ.)
Lab. experiments
Tokyo, Tokyo Metropolitan, Osaka, Tokai Univs. JAXA)

8. Izu 2000 events (volcanic eruption and intense seismic activity)
3-comp. magnetometer array

9. Izu 1998-2000 Activity started Eigenvalue (λ3, 0.1Hz)
Izu Pen.3-comp. Mag array.
E-field Niijima (0.01Hz)
1998
1999
2000

10. Telluric current record

11. Collapsed station
at Kozu Island
July 2002

13. VAN method
Greek scientists, Varotsos, Alexopoulos, and Nomikos initiated in 1980’s.
Based on multi-dipole DC-electric field observation
Anomaly (SES) appears before the impending sizable earthquake (EQ).
They claimed that they predicted M≥5 Greek EQs. The criteria for successful prediction are: < a few weeks in time, <0.7 units in magnitude (M, hereafter), and <100 km in epicentral distance. The length of time window depends on the type of signals (a few days to months).

14. Recognition of the VAN method
Generally, not well recognized among the seismological community
A lot of debates/counterarguments
Recent EOS articles
Geophys. Res. Lett. 23 (debates of VAN)
VAN group’s way of writing is not reader oriented (difficult to understand)

15. On going forecast!

16. Cornell University website http://arxiv.org/abs/0904.2465
The same holds for a non-dichotomous signals
on March 28, 2009 at Keratea station located
close to Athens (Fig. 8)
To approach the occurrence time of the impending
event, the procedure developed in Ref 32 has been
employed for the seismicity within are N37.7-
38.8, E

17. Natural Time Analysis P. A. Varotsos and his group
Natural Time Analysis is effective to predict a critical point in the time-series of critical phenomena.
Large earthquakes
Varotsos et al., Phys. Rev. E, 2002, 2003, 2006, 2007
Phase transition on 2D Ising spin systems
Varotsos et al., Phys. Rev. E, 2003
Heart attack
Varotsos et al., Phys. Rev. E, 2004, 2005
(New Scientist)

18. (Varotsos, Is time continuous ?, submitted to Phys. Rev. Lett., 2008)
Natural Time
k : k th event
N : total number of events
(Varotsos, Is time continuous ?, submitted to Phys. Rev. Lett., 2008)

19. Self-organized Criticality
Plate motion
Is EQ SOC phenomenon ?
Critical phenomena -> SOC o
SOC -> Critical phenomena X
EQs
(Sand pile model)
Bak et al., Phys. Rev. Lett. (1987)
Bak & Tang J. Geophys. Res. (1989)

20. (Long range correlation)
Critical point
Critical point
(Long range correlation)
Triggering ?
Large EQ
実際の時系列データを用いて説明。また、GMTによる地震活動図も入れる（地震が起きた順番も入れた方が良い）。
臨界点と臨界状態を区別して説明。

21. One Case (Conventional Time)
Divorce
Critical Point
Extramarital affair
Energy
Second affair
First Fight
Fight
Fight
Conventional Time

22. Another Case (Conventional Time)
Divorce
Critical Point
Extramarital affair
Energy
Second affair
First Fight
Fight
Fight
Conventional Time

23. Similar Shape
Energy
Natural Time 1

24. Power spectrum at Critical Point ?
Qxk
: Seismic Moment
: Natural frequency ω
Power spectrum at Critical Point ?

25. Candidate of Critical Point

26. Coincidence

27. Time series of
経験則の話。
Coincidence
Coincidence

28. Coincidence Scale invariance True Coincidence True Coincidence
(Magnitude and Area)
True Coincidence

29. 2000 Izu Swarm EQs (Uyeda, Kamogawa & Tanaka, JGR, 2009)

30. Time-series of power spectrum

31. Time series of k1
Candidate of
True Coincidence

32. Tentative conclusion
EM phenomena may reflect critical state of the crust (at least Greek group claims that SES is a critical phenomenon)
EM phenomena are not statistical but deterministic ones
Combination of multi-parameter monitoring is essentially important
If EQs are critical phenomena, Natural Time analysis may connect seismicity and SES activity (EM phenomena)

33. Future Plans
Proceed RTL algorism research with Prof. Huang (Peking University)
Proceed Natural Time analysis
Proceed cooperation with Keilis-Borok group
To solve fundamental problem of EM phenomena related to EQs
EM signal generation and transmission
To proceed LAI (lithosphere-Atmosphere and Ionosphere) coupling study
-> to merge mechanical process and EM phenomena

34. Both Seismic activity and Ionosphere are
really near earth surface matter !

35. Preseismic LAI coupling
Kamogawa (2006)

36. References
Fraser-Smith et al., Low-frequency magnetic field measurements near the epicenter of the Ms 7.1 Loma Prieta earthquake, Geophys. Res. Lett., 17, , 1990.
Nagao et al., Electromagnetic anomalies associated with 1995 KOBE earthquake, J. Geodynamics, 33, , 2002.
For Natural Time
SARLIS et al., Investigation of seismicity after the initiation of a Seismic Electric Signal activity until the main shock, Proceedings of the Japan Academy, Series B,  Vol. 84 , No. 8, , 2008.
Varotsos, The Physics of Seismic Electric Signals, TerraPub, Tokyo, Japan, 338 pp., 2005.
Uyeda et al., Analysis of electrical activity and seismicity in the natural time domain for the volcanic-seismic swarm activity in 2000 in the Izu Island region, Japan, JGR, 114, B02310, doi: /2007JB005332, 2009.
For LAI coupling
Kamogawa, M., Preseismic Lithosphere-Atmosphere-Ionosphere Coupling, EOS, Vol. 87, Num. 40, 417, 424, 2006.