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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. Today ’ s talk. What is “ Seismo-Electromagnetics ” - PowerPoint PPT PresentationTRANSCRIPT
We are here!
Tokyo
Nagoya
Earthquake Prediction Research Center, Tokai University
Toshiyasu NAGAO
Combined approach using the electromagnetic precursory phenomena and critical phenomena for a
short-term earthquake prediction
Today’s talk What is “Seismo-Electromagnetics”
some examples (California and Japan) Greek VAN method Introduction of Natural Time analysis Introduction of LAI (Lithosphere-Atmosp
here and Ionosphere) coupling
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 !
M7.1 Loma Prieta (California) EQ in 1989
Seismo-Electromagnetics in Japan
100M
10M
1M
100k
10k
1k
100
10
1
0.1
DC
(Hz)
ULF
VHF
HF
MF
LF
VLF
ELF
telluric current
3-comp. magnetic
Narrow band 3-comp. magnetic2-comp. magnetic for direction findingEM pulse measurements in a boreholeAnomalous transmission of radio waves
Natural noise observation
Blue letters Ionosphere/troposphere anomaly (radio wave transmission anomaly)
Brown letters Signals emitted from the lithosphere
Micro wave observation
Vertical E-field measurements in a borehole
FM broadcast wave anomalous transmission
Nagao et al., 2002(J. Geodynamics)
Seismo-Electromagnetic studies in Japan
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.)
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)
Signals emitted from the lithosphere
Ionosphere/troposphere anomaly
Izu 2000 events (volcanic eruption and intense seismic activity)
3-comp. magnetometer array
Izu 1998-2000
1998 1999 2000
E-field Niijima (0.01Hz)
Eigenvalue (λ3, 0.1Hz)Izu Pen.3-comp. Mag array.
Activity started
Telluric current record
Collapsed station at Kozu Island
July 2002
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. Th
e 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).
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 orie
nted (difficult to understand)
On going forecast!
http://arxiv.org/abs/0904.2465
Cornell University website http://arxiv.org/abs/0904.2465
The same holds for a non-dichotomous signals on March 28, 2009 at Keratea station locatedclose to Athens (Fig. 8)To approach the occurrence time of the impendingevent, the procedure developed in Ref 32 has beenemployed for the seismicity within are N37.7-38.8, E22.6-24.1.
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)
Natural Time
(Varotsos, Is time continuous ?, submitted to Phys. Rev. Lett., 2008)
k : k th event
N : total number of events
Self-organized Criticality
(Sand pile model)
Bak et al., Phys. Rev. Lett. (1987)Bak & Tang J. Geophys. Res. (1989)
Is EQ SOC phenomenon ?
Plate motion
EQs Critical phenomena -> SOC oSOC -> Critical phenomena X
Critical point
Critical point(Long range correlation)
Triggering ?
Large EQ
One Case (Conventional Time)
En
erg
y
Fight
Extramarital affair
Divorce
First FightSecond affair
Fight
Critical Point
Conventional Time
Another Case (Conventional Time)
Conventional Time
En
erg
y
Fight
First Fight
Fight
Critical Point
Extramarital affair
Second affair
Divorce
Similar ShapeEn
erg
y
Natural Time0 1
Power spectrum
: Natural frequency
: Seismic Moment
Power spectrum at Critical Point ?
Qxk
ω
Candidate of Critical Point
Coincidence
Time series of
Coincidence Coincidence
True Coincidence
Scale invariance(Magnitude and Area)
Coincidence
True Coincidence
2000 Izu Swarm EQs(Uyeda, Kamogawa & Tanaka, JGR, 2009)
Time-series of power spectrum
Time series of k1
Candidate ofTrue Coincidence
Tentative conclusion EM phenomena may reflect critical state of the crust (a
t 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)
Future Plans Proceed RTL algorism research with Prof. Huang (Pe
king University) Proceed Natural Time analysis Proceed cooperation with Keilis-Borok group To solve fundamental problem of EM phenomena rel
ated to EQs EM signal generation and transmission To proceed LAI (lithosphere-Atmosphere and Ionosp
here) coupling study
-> to merge mechanical process and EM phenomena
Both Seismic activity and Ionosphere are really near earth surface matter !
Preseismic LAI coupling
Kamogawa (2006)
References Fraser-Smith et al., Low-frequency magnetic field measurements near the epic
enter 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 Elec
tric 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, E
OS, Vol. 87, Num. 40, 417, 424, 2006.