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Title: Ground-based%20Electromagnetic%20Observations%20For%20Monitoring%20Volcanoes%20and%20Earthquakes%20%20IGY%20


1
Ground-based Electromagnetic Observations For
Monitoring Volcanoes and Earthquakes IGY eGY
16-19 September 2007 (Suzdal, Russia)
From visual observations to International
Virtual ElectroMagnetic Laboratory IVEML
  • Coordination Jacques Zlotnicki, CNRS, France
  • Email jacques.zlotnicki_at_opgc.univ-bpclermont.fr
  • A. Gvishiani, R.P. Singh, J.L. Le Mouël,
  • M.Rodkin, G. Vargemezis, Sh. Bogoutdinov, S.
    Agayan, Senthilkumar, Li Feng

2
Human, financial, and economical costs of
volcanic eruptions
  • The eruption of Nevado del Ruiz (Colombia) Nov.
    13, 1985
  • ¾ of Amero city disappeared
  • 23 000 deaths 5 000 casualties,
  • Cost 7.7 billion dollars 20 of the PIB
  • The 2002 eruption of Etna
  • No casualty
  • Re-routage of air traffic, airport closed
  • Economical sector of tourism strongly affected
  • 800 M ( gt 1 M) (Bull. Soc. Volc. Eur., N6,
    2002)

3
Human, financial, and economical costs of
Earthquakes
  • Sumatra earthquake December 26, 2004
  • Magnitude 9.3
  • Tsunami hits Indonesia, East coast of Sri Lanka,
    South of India, and South of Thailand as well
  • Incredible number of killed persons 
  • More than 220 000
  • ONU support (February 2005)
  • 7 000 M

Tsunami hits in Thailand
4
NATURAL HAZARDS MITIGATION
  • Natural (and artificial) catastrophes may induce
    huge human, economical, and environmental costs
  • VE and EQ cannot be controlled but their impacts
    could be reduced if some strategies are achieved
  • Infrastructures have to be well built, and
    efficient Civil Protection maps should be
    designed,
  • Accurate scenarios of eruptive dynamisms and
    faults rupture should be available,
  • Development of researches likely to better
    understand the genesis of EQ and VE, and to
    forecast them
  • Methodologies, technical improvement of sensors,
    real time monitoring and processing ...
  • Seismology, Deformation, stress field, Fluids,
    Geochemistry, abnormal behaviors
  • and Electromagnetism

5
EVOLUTION OF EM STUDIES
  • Understanding EM phenomena in the 1950s
  • Manual Observations 1940-1960
  • Analog records 1960-1980
  • Digital investigations 1985
  • Real time data recording and new investigations
    1985-1995
  • Development of detailed data processing,
    multi-parametric analyses 1995
  • Integration of combined geophysical methods,
    intern. cooperations 2000
  • Development of real time monitoring based on
    ground-based and satellite observations 2004
  • The electronic era Development of expert systems
    through international cooperation

6
MULTI PARAMETRIC EM OBSERVATIONS ON VOLCANOES
Low dense networks - Low data sampling ? Poor
description
7
UPHEAVAL BROUGHT BY PC COMPUTERS
  • 1990 PC computers are used!
  • 1992 Automatic data transfers from remote
    observatories to researches centers are performed
    (modem), and simple data processing are routinely
    done every day.
  • The number of sensors increases
  • on the field

Up to 6 telemeter stations are set in the field
8
SP CHANGES PRECEDING THE 1998 ERUPTIVE ACTIVITY
La Fournaise (ULF band)
days 57 and 72 (1998)
Zlotnicki et al., 2001
9
ELECTRIC OSCILLATIONS (2200-0400 LT)
March 1998 eruption
  • Periodic variations (T lt 180 s)
  • Such SP signals also appear 5 days before the
    eruption
  • There is no tilt variation of more than 1 mrad
  • The hypocenters are still at 2 km below the s.l.

10
Electric and tilt variations associated with the
upward magma migration
March 9, 1998
  • Up to 2000mV/km
  • Up to 800 µrad

Ground deformations From Staudacher
IUGG, 2003
11
(No Transcript)
12
TECHNICAL IMPROVEMENTS TO A BETTER SCIENTIFIC
EFFICIENCY 1994
  • The number of EM stations increases, and
    techniques are improved
  • PC computers are commonly used but their
    performances are still limited
  • EM studies are still focused on low frequency
    records (T1mn)
  • All the components of the EM field give valuable
    information but they are processed separately
  • Progress needs to
  • To combine all EM methods in order to get a
    better description of phenomena
  • Overcome the small critical mass of national
    teams, and therefore implement international
    cooperations (wider expertise)

13
JULY 8, 2000 MIYAKE-JIMA ERUPTION (Japan)
Cooperation France-Japan (PICS, MAE) after 1994
June 26, 2000 Seismicity appears
July 8 Eruption?caldera formation
Sasai et al., 2002 Zlotnicki et al., 2003
14
EM SIGNALS RELATED TO EARTHQUAKES
Modified from Hattori, IAGA-2005
15
KOBE EARTHQUAKE 1995 (Japan)
  • M 7.2 earthquake (5h45 on January 17, 1995)
  • No precursory micro seismicity
  • Post EQ studies have shown that some signals
    might have occurred before the EQ
  • Perturbations of radio signals (30-300 kHz) (Bari
    Univ.)
  • Anomalies in VLF transmissions (Chofu-Shi Univ.)
  • Changes in the water levels (Hiroshima Univ.)
  • 222Rn emission (Hiroshima Univ.)
  • Abnormal biological behaviors (Osaka Univ.)

16
SEISMO ELECTRIC EFFECTS M5.7 July 21, 1995 YONG
DENG EARTHQUAKE (China)
Observations A clear systematic decrease of the
frequency of the maximal electric energy was
observed during two months starting 1 month
before the EQ. (200 to about 1000 sec) Small
step like fluctuations were also
recorded Signals stop 2 weeks after the EQ
Zlotnicki et al., 2001
17
CNRS-CEA cooperation on Tianzhu fault
X-component
Y-component
geomagnetic
geoelectric
The anomaly of the frequency spectrum recorded at
SNH station before the Yongdeng Ms5.8 EQ of 1995,
24h2h periods Li Ning,Du Xue-bin et al.,2007.
The Imminent Electro-Magnetic Phenomena Related
to Earthquakes Recorded At the SNH Station (in
Chinese and in publication).
Tianzhuxi (1996) Ms5.4 Jingtai (2000) Ms5.9
Minle-Sheridan (2003) Ms6.1 (2 st.)
18
EARTHQUAKES GENERATION PHYSICAL PROCESSES
  • Rn emission and air ionization
  • Release of fluids and gas generating gravity
    waves
  • Thermal anomalies
  • Propagation of EM waves

19
THE ELECTRONIC REVOLUTION
  • 2000 The Internet revolution and the fantastic
    increase of PC capabilities
  • Strengthen communication, data exchanges,
    international scientific programs
  • Allow new deeper investigations and data
    processing (on-line)
  • Launch new researches in unknown domains (high
    frequency domain)
  • Allow to organize a powerful international man
    power interaction on common fields of interest
  • Systematic complex data processing
    (CNRS-Geophysical Centre, RAS)
  • Densification of multi-scale sensors (i.e.
    ground-based and satellite Demeter)
  • Integration of multi-techniques (EMseismicity,
    ground deformation, geochemistry ) giving rise
    to a more complete picture of the hazards
  • 2004-2007 New international researches on
    volcanoes and earthquakes leading to the
    development of expert systems.
  • The unrest of Taal volcano (Philippines)
  • The slow unrest of Hachijo-jima volcano (Japan)
  • Demeter mission devoted to Earthquakes and
    Volcanic Eruptions

20
DEMETER mission LPCE (Main P.I. M. Parrot)
Project The DEMETER satellite has been launched
on June 29, 2004 by a Dnepr rocket from
Baïkonour. The scientific objectives are related
to the study of ionospheric perturbations in
relation with the seismic and volcanic
activities. (from DC to 20 Khz)
293 earthquakes with M gt 5.5
500-800 Hz gt 4 kHz -
Parrot et al., 2006
21
EM PHENOMENA RELATED TO EQ AND VE
  • The ground-based EM stations follow several
    objectives
  • To seek and identify abnormal variations in the
    ULF, ELF, and VLF frequency domains likely to be
    generated by a tectonic activity,
  • To discriminate the origin of the signals
    (anthropogenic or tectonic origin ),
  • To evaluate the localisation of the source(s)
    and the propagation of signals,
  • To validate the observations made on board of
    Demeter satellite,
  • To understand the mechanisms generating EM
    signals and the Lithosphere-Atmosphere-Ionosphere
    (LAI) coupling

? Widening studies in the complete spectrum of
the EM field ? Development of data processing and
signal pattern recognition ? Integration of
multi-parametric techniques, associated with
other geophysical methods in a multi-scale
environment ? Dense EM networks are needed
  • Data processing cannot be done any more manually!
  • Pattern recognition and artificial intelligence
    methods have to be developed and processed
    on-line (Cooperation with Geophysical
    Centre-RAS)

22
SEISMIC HAZARDS IN CORINTH GULF (Greece) EM
NETWORK
http//www.ngdc.noaa.gov/seg/topo/globega2.shtml
  • DEMETER station is located in Trizonia Island
    (ULF, ELF, (VLF)),
  • Mag, Elec., sismo. 1 Hz
  • One ULF station is set at Psaromita cape
  • Mag., Elec., sismo. 1 Hz
  • A new station (CEFIPRA) is now operating on
    Aigion fault (ULF, ELF),
  • Mag, Elec., sismo. 1 Hz

Supports CNES (Demeter mission), CEFIPRA
(India), and bilateral exchanges (CNRS)
23
TRIZONIA STATION ULF, ELF, VLF
100 Hz, 6 channels (EQ, Ex, Ey, H, D, Z) gt 200
Mo/day Corinth 3 stations, 1 VLF ? 2 To to
process per year
24
NETWORK, DATA TRANSMISSION, DATABASE
Data acquisition
Trizonia
Cables setting
WiFi link
Database
Internet, server
25
CO-SEISMIC EVENTS AND SEISMIC GAP
  • EQ, even of low Ms (2.6) have generated CSES,
  • up to 3 mV/km (red triangles)
    Data set 250 EQ (distance lt 300 km)
  • CSES are mainly observed for EQ, even of small
    magnitude at a distance lt 100 km
  • CSES appear along the seismic gap
  • Weak signals seem to precede these small EQ Needs
    a detailed study

A seismic crisis started along the seismic gap on
November 2006
Relationship exists between the occurrence of
CSES and the existing seismic gap ?
26
FUZZY PATTERN SIGNAL RECOGNITION CNRS GC RAS
cooperation
Difference Recognition Algorithm for Signal
Fuzzy Logic Algorithm for Signal
Genuine anomaly
Potential anomaly
Raw time serie
Definition A positive function (rectification
function) ? is defined on consecutive fragments
of each time record. Examples.
Length of the fragment L(?k y)Syj1-yj, j
k-?/h ,.., k?/h, Energy, number of zero
crossing, etc.
DRAS. Calm and anomaly points are quite well
distinguished, but genuine anomalies are not
evident. DRAS is useful in searching big
anomalies. FLARS. High amplitude anomalies are
quite obvious and small anomalies are not so
evident on the background of noise. Useful to
search very small isolated anomalies.
27
APPLICATION OF DRAS ALGORITHM Corinth
First, seismic events are identified and electric
signals are looked for in a specific time window
Second, AI is extended to all data sets and data
collection of electric (magnetic) signals is built
28
A POTENTIAL HYPOTHESIS
CSES
time
T. of EQ
propagation
  • Increase of the stress field
  • Modification of rocks properties and the
    surroundings
  • Deformation, temporary re-opening of cracks
  • Increase of the permeability, fluids transfer
  • Increase of the electrical conductivity of the
    ground

station
Topographic surface
Corinth gulf
Water saturated medium
Fault trace
EQ
29
WORK IN PROGRESS
30
INTERNATIONAL VIRTUAL ELECTROMAGNETIC
LABORATORY A way to contribute to Hazards
mitigation
The idea is to use international expertise's on
common topics related to Natural Hazards (VE, EQ)
Geophysical Centre RAS (Moscow) Artificial
Intelligence
Indian Institute of Technology (Kanpur) GIS,
Satellite imageries
CNRS (Clermont-Fd) LPCE Data
processing-Networks EM field, satellite data
EQ Corinth (Greece) Tianzhu (China) VE
Taal (Philippines) Fournaise (France)
China Earthq. Adm. (Lanzhou) EM field,
resistivity
PHIVOLCS (Manila) Volcano monitoring
Aristotèles Lab. (Thessaloniki) Seismic data,
Field exp.
Earthq. Pred. Res. Centre (Tokai) ERI, Tokyo
Metro. City EM field, data processing
VE Hachijo-jima Merapi EQ Izu Peninsula
Romanian Acad. Sci. ? Vrancea zone
Volcanological Survey (Indonesia)
31
CONCLUDING REMARKS
  • Management of the Environment and Economy,
    necessity to include Natural Hazards (in
    particular VE, EQ) in the Information Societies,
    and finally to give real time information in an
    expert mode to Civil Authorities are key points
    for risk mitigation and potential emergency
    management. It is the duty of any country.
  • National educational and researches funds do not
    permit to initiate, evaluate, and launch many
    innovative monitoring methods.
  • National teams have not an adequate critical mass
    and expertise to complete all the tasks

But
  • EM methods can be efficient for monitoring VE and
    EQ, and become very powerful if they are
    integrated in multi-scale and multi-technical
    environments.
  • An outstanding expertise is available in the
    World in almost any field of Natural Hazards.
    Combining efforts on a same topic is a key issue
    for the future.
  • The electronic era can rub out the lack of
    communication. It contributes to build virtual
    laboratories able to solve complex problems.
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