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1. 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. ＤＣ 0.1 1 10 100 1ｋ 10ｋ 100ｋ 1Ｍ 10Ｍ 100Ｍ （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) 2000 1998 1999

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! http://arxiv.org/abs/0904.2465

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, E22.6-24.1.

17. (New Scientist) 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

18. k : k th event N : total number of events Natural Time (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. Triggering ? Large EQ Critical point Critical point (Long range correlation)

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

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

23. Similar Shape Energy 0 Natural Time 1

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

25. Candidate of Critical Point

26. Coincidence

27. Coincidence Coincidence Time series of

28. True Coincidence Coincidence Scale invariance (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. Tentativeconclusion • 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, 1465-1468, 1990. • Nagao et al., Electromagnetic anomalies associated with 1995 KOBE earthquake, J. Geodynamics, 33, 401-411, 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, 331-343, 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:10.1029/2007JB005332, 2009. For LAI coupling • Kamogawa, M., Preseismic Lithosphere-Atmosphere-Ionosphere Coupling, EOS, Vol. 87, Num. 40, 417, 424, 2006.