EMSEV-DEMETER JOINT WORKSHOP September 7-12, 2008 SINAIA, ROMANIA - - PowerPoint PPT Presentation

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EMSEV-DEMETER JOINT WORKSHOP September 7-12, 2008 SINAIA, ROMANIA - - PowerPoint PPT Presentation

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EMSEV-DEMETER JOINT WORKSHOP September 7-12, 2008 SINAIA, ROMANIA SHORT- -TERM EM PRECURSORY TERM EM PRECURSORY SHORT PARAMETERS RELATED TO THE PARAMETERS RELATED TO THE INTERMEDIATE DEPTH EARTHQUAKES INTERMEDIATE DEPTH EARTHQUAKES D.

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SLIDE 1

SHORT SHORT-

  • TERM EM PRECURSORY

TERM EM PRECURSORY PARAMETERS RELATED TO THE PARAMETERS RELATED TO THE INTERMEDIATE DEPTH EARTHQUAKES INTERMEDIATE DEPTH EARTHQUAKES

  • D. Stanica, D.A. Stanica, N. Vladimirescu, M.Popescu

EMSEV-DEMETER JOINT WORKSHOP

September 7-12, 2008 SINAIA, ROMANIA

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SLIDE 2

OUTLINE : OUTLINE : OUTLINE : OUTLINE :

♦ ♦ Seismic active Seismic active Vrancea zone Vrancea zone – – intermediate depth EQ; intermediate depth EQ; ♦ ♦ Ground Ground-

  • base monitoring technique used to emphasize

base monitoring technique used to emphasize the electromagnetic marks related to the intermediate the electromagnetic marks related to the intermediate depth earthquakes: depth earthquakes:

1.

  • 1. Electromagnetic (EM) phenomena/parameters related to earthquakes

Electromagnetic (EM) phenomena/parameters related to earthquakes 2. 2. EM studies for EM studies for pattern recognition pattern recognition in order to select the in order to select the optimum site

  • ptimum site
  • f observation;
  • f observation;
  • 3. Continuous monitoring to get the geomagnetic field;
  • 3. Continuous monitoring to get the geomagnetic field;
  • 4. Results :
  • 4. Results :
  • daily mean distribution of the Bzn parameter used as possible

daily mean distribution of the Bzn parameter used as possible precursory marks of the EQ precursory marks of the EQ

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SLIDE 3

Vrancea zone

OS OS

  • Surlari Obsevatory

selected site for continuous monitoring of the EM field

Vrancea zone Vrancea zone Vrancea zone Vrancea zone – – intermediate depth EQ intermediate depth EQ intermediate depth EQ intermediate depth EQ

EQ DEPTH > 50Km

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SLIDE 4

DEPTH [Km] L A T I T U D E L O N G i T U D E

Vrancea zone Vrancea zone Vrancea zone Vrancea zone

Intermediate depth EQ Intermediate depth EQ Intermediate depth EQ Intermediate depth EQ

Strong intermediate-depth rong intermediate-depth EQs (since 1600) since 1600)

  • No. Date (month/day/year) Magnitude

1 9/01/1637 6.6

  • 2. 9/09/1679 6.8

3. 8/18/1681 6.7 4. 6/12/1701 6.9

  • 5. 10/11/1711 6.7
  • 6. 6/11/1738 7.0
  • 7. 4/06/1790 6.9
  • 8. 10/26/1802 7.4
  • 9. 11/17/1821 6.7

10. 11/26/1829 6.9

  • 11. 1/23/1838 6.9
  • 12. 10/06/1908 6.8
  • 13. 11/01/1929 6.6
  • 14. 3/29/1934 6.9
  • 15. 11/10/1940 7.4

16. 3/04/1977 7.5

  • 17. 8/30/1986 7.2

18. 5/30/1990 6.9

  • 19. 10/27/2004 6.0

BUCHAREST – March 04, 1977 (about 1500 people died)

Low resistivity Low resistivity

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SLIDE 5

Electromagnetic (EM) phenomena/parameters Electromagnetic (EM) phenomena/parameters Electromagnetic (EM) phenomena/parameters Electromagnetic (EM) phenomena/parameters related to earthquakes related to earthquakes related to earthquakes related to earthquakes

  • Signals

possibly emitted from earthquakes sources:

  • geomagnetic/ geoelectric changes in ULF –

ELF – VLF – LF – HF bands;

  • Anomalous

transmission

  • f

electromagnetic waves due possibly to disturbed ionosphere:

  • transmission anomaly of man-made waves

(VLF) and scattering of MF radio waves (VHF);

  • Anomalous behaviour of the EM parameters:
  • the electric conductivity changes in seismic

active zones and their neighborhood.

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SLIDE 6

Theoretical information regarding the Theoretical information regarding the Theoretical information regarding the Theoretical information regarding the normalized function Bzn normalized function Bzn normalized function Bzn normalized function Bzn

Surface vertical magnetic component (Bz) is an entirely secondary field and its existence is an immediate indicator of the lateral inhomogeneity. For 2D structure the Bz is produced essentially by B┴ and consequently: Bzn(f) = Bz(f) / B┴ (f) , (1) should be time invariant for a given 2D structure in non seismic conditions. We may compute: ρz (f)=0.2/f .│E║ (f)/Bz (f)│2, (2) where f is frequency (Hz) and E║ is electric field parallel to the strike Also: ρ║ (f) = 0,2/f .│E║ (f)/B┴ (f)│2 , (3) thus, in terms of resistivity: │Bzn (f) │= [ρ║ (f)/ ρz (f)]1/2 ρn =ρ║ (f)/ ρz (f) (4) (Bzn could be linked to variation of the electric conductivity at the different depth levels into the Earth)

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SLIDE 7

2D modeling by using the finite element code 2D modeling by using the finite element code

Approximate field solutions were computed for two simple 2D geometries: 1. The sloping interface solution was obtained by summing all plane waves propagation at real angle, ignoring effects of apex ;

  • 2. The vertical contact

solution was computed for two resistivities.

The similarity in the properties of Bzn for the both models is

  • f

interest in our study

.

1 2 3 4

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SLIDE 8

EM studies for EM studies for pattern recognition pattern recognition in order to select the in order to select the optimum site

  • ptimum site
  • f observation
  • f observation
  • Type of the geoelectrical

structure (skew) ;

  • Strike orientation

in order to determine B┴ ;

  • Distribution of the Bzn

parameter in non seismic conditions.

  • Vrancea zone

OS OS

  • Surlari Observatory

selected for continuous monitoring

Intermediate depth EQ

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SLIDE 9

Geophysical equipment used for establishing the Geophysical equipment used for establishing the g geoelectric pattern of the measuring point eoelectric pattern of the measuring points s

  • ADU 06 with 5 channels, 24 bits
  • Electromagnetic

system GMS-06 used for discrete measurements (ADU 06 with 5 channels, 24 bits; EFP-06 are E-field sensors; Hx, Hy, Hz are induction coil magnetometers; laptop-for real time MT data estimation).

Electric sensor Magnetic sensor (induction coil) 2 frequency ranges:

  • HF = 0.5kHz -

24 kHz;

  • LF = 10-4 Hz - 1kHz

Hx Hz Hy

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SLIDE 10

EM monitoring and pattern recognition EM monitoring and pattern recognition

“ “MAPROS MAPROS” ” – – PACKAGES PROGRAM PACKAGES PROGRAM

Real time Real time EM EM series and series and MT MT parameters parameters

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SLIDE 11

“ “MAPROS MAPROS MAPROS MAPROS” ”

  • PACKAGES PROGRAM

PACKAGES PROGRAM PACKAGES PROGRAM PACKAGES PROGRAM

Resistivity and phase Resistivity and phase

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SLIDE 12

“ “MAPROS MAPROS MAPROS MAPROS” ”

  • PACKAGES PROGRAM

PACKAGES PROGRAM PACKAGES PROGRAM PACKAGES PROGRAM

Real time display of Real time display of the resistivity ( the resistivity ( Real time display of Real time display of the resistivity ( the resistivity (ρ ρ║

║

, , ρ ρ┴

┴

) ) and phase ( and phase ( and phase ( and phase (n n║

║

, , , , n n

┴ ┴)

)

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SLIDE 13

“ “MAPROS MAPROS MAPROS MAPROS” ”

  • PACKAGES PROGRAM

PACKAGES PROGRAM PACKAGES PROGRAM PACKAGES PROGRAM

SKEW SKEW

Skew should be < 0.3 for 2D structure

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SLIDE 14

“ “MAPROS MAPROS MAPROS MAPROS” ”

  • PACKAGES PROGRAM

PACKAGES PROGRAM PACKAGES PROGRAM PACKAGES PROGRAM

STRIKE STRIKE

STRIKE STRIKE

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SLIDE 15

Data acquisition module for continuous Data acquisition module for continuous Data acquisition module for continuous Data acquisition module for continuous monitoring of monitoring of the Geomagnetic f the Geomagnetic field ield monitoring of monitoring of the Geomagnetic f the Geomagnetic field ield

MAG-03DAM MAG-03DAM acquisition module acquisition module 6 channel, 24 bit resolution, sampling rate programmable, internal and external battery of 12 V , data storage on laptop HD; Geomagnetic System Configuration

3 axes magnetic sensor

Frequency range: 3kH-DC

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SLIDE 16

Provita Provita de de Sus Sus

  • Geodynamic Observatory

Geodynamic Observatory

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SLIDE 17

Time variation of the Time variation of the geomagnetic geomagnetic components components B B⊥

⊥

, B , BII

II and

and Bz Bz

BZ BII B┴

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SLIDE 18

Bzn disturbances linked Bzn disturbances linked to to the seismic the seismic events events

Bzn = Bz/Bperp.(November 2002)

1,87 1,872 1,874 1,876 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

Days Bzn

4.3 3.6 3.0

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SLIDE 19

Bzn disturbances linked Bzn disturbances linked to to the seismic events the seismic events

1,87 1,871 1,872 1,873 1,874 1,875 1,876

1.2.03 2.2.03 3.2.03 4.2.03 5.2.03 6.2.03 7.2.03 8.2.03 9.2.03 10.2.03 11.2.03 12.2.03 13.2.03 14.2.03 15.2.03 16.2.03 17.2.03 18.2.03 19.2.03 20.2.03 21.2.03 22.2.03 23.2.03 24.2.03 25.2.03 26.2.03 27.2.03 28.2.03 1.3.03 2.3.03 3.3.03 4.3.03 5.3.03 6.3.03 7.3.03 8.3.03 9.3.03 10.3.03 11.3.03 12.3.03 13.3.03 14.3.03 15.3.03 16.3.03 17.3.03 18.3.03 19.3.03 20.3.03 21.3.03 22.3.03 23.3.03 24.3.03 25.3.03 26.3.03 27.3.03 28.3.03 29.3.03 30.3.03 31.3.03 1.4.03 2.4.03 3.4.03 4.4.03 5.4.03 6.4.03 7.4.03 8.4.03 9.4.03 10.4.03 11.4.03 12.4.03 13.4.03 14.4.03 15.4.03 16.4.03 17.4.03 18.4.03 19.4.03 20.4.03 21.4.03 22.4.03 23.4.03 24.4.03 25.4.03 26.4.03 27.4.03 28.4.03 29.4.03 30.4.03

Timp (zile) Bzn

3.2 3,.5 2.8 3.1 2.8 3.1 3.0 3.2 2.9 3.1 3.0 3.1 4.1 3.3 2.8 3.7 4.3 4.3 4.3/MN 3.1 2.8 3.2

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SLIDE 20

Mean daily values of Mean daily values of

normalized normalized resistivity resistivity ( (ρ

ρn

n)

) reprezented simultaneously with seismic events. reprezented simultaneously with seismic events.

3,509 3,51 3,511 3,512 3,513 3,514 3,515 3,516 3,517 01.06.2004 02.06.2004 03.06.2004 04.06.2004 05.06.2004 06.06.2004 07.06.2004 08.06.2004 09.06.2004 10.06.2004 11.06.2004 12.06.2004 13.06.2004 14.06.2004 15.06.2004 16.06.2004 17.06.2004 18.06.2004 19.06.2004 20.06.2004 21.06.2004 22.06.2004 23.06.2004 24.06.2004 25.06.2004 26.06.2004 27.06.2004 28.06.2004 29.06.2004 30.06.2004 Time [days] ROn=ROpar/Roz 3.4/140km 4.2/33km 4.6/33km 3.6/132km 3.4/13km 3.7/8km

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SLIDE 21

Bzn disturbances linked Bzn disturbances linked to to the seismic events the seismic events

1,874 1,875 1,876 1,877 1,878 1,879 1,880 01.09.2004 02.09.2004 03.09.2004 04.09.2004 05.09.2004 06.09.2004 07.09.2004 08.09.2004 09.09.2004 10.09.2004 11.09.2004 12.09.2004 13.09.2004 14.09.2004 15.09.2004 16.09.2004 17.09.2004 18.09.2004 19.09.2004 20.09.2004 21.09.2004 22.09.2004 23.09.2004 25.09.2004 26.09.2004 27.09.2004 28.09.2004 29.09.2004 30.09.2004 01.10.2004 02.10.2004 03.10.2004 04.10.2004 05.10.2004 06.10.2004 07.10.2004 08.10.2004 09.10.2004 10.10.2004 11.10.2004 12.10.2004 13.10.2004 14.10.2004 15.10.2004 16.10.2004 17.10.2004 18.10.2004 19.10.2004 20.10.2004 21.10.2004 22.10.2004 23.10.2004 24.10.2004 25.10.2004 26.10.2004 27.10.2004 28.20.2004 29.10.2004 30.10.2004 31.10.2004 TIME [days] Bzn=Bz/Bperp.

3.2 3.2 3.3 3.3 3.1 3.0 4.6 3.2 3.1 3.2 3.4 3.1 3.5 4.4 3.2 6.0 124km 147 116km 164 142 145 166 148 crustal 149 140 123 148 171 100km

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SLIDE 22

Bzn disturbances linked Bzn disturbances linked to to the seismic events the seismic events

Bzn (27 December- 13 February 2006)

3.3(122.04) 4.3(144.86) 3.1(134.43) 2.7(118.6) 3.7(15.9) 3.2(133.63) 2.3(27.67) 2.9(111.92) 3.1(89.57) 2.5(58.42) 3.2(125.07) 2.1(32.55) 2.7(136.32) 4.1(22.49) 3.6(131.49) 2.8(89.31) 2.8(76.71) 2,032 2,034 2,036 2,038 2,04 2,042 2,044

27.12.2005 28.12.2005 29.12.2005 30.12.2005 31.12.2005 01.01.2006 02.01.2006 03.01.2006 04.01.2006 05.01.2006 06.01.2006 07.01.2006 08.01.2006 09.01.2006 10.01.2006 11.01.2006 12.01.2006 13.01.2006 14.01.2006 15.01.2006 16.01.2006 17.01.2006 18.01.2006 19.01.2006 20.01.2006 21.01.2006 22.01.2006 23.01.2006 24.01.2006 25.01.2006 26.01.2006 27.01.2006 28.01.2006 29.01.2006 30.01.2006 31.01.2006 01.02.2006 02.02.2006 03.02.2006 04.02.2006 05.02.2006 06.02.2006 07.02.2006 08.02.2006 09.02.2006 10.02.2006 11.02.2006 12.02.2006 13.02.2006

Days Bzn 1 1,5 2 2,5 3 3,5 4 4,5 magnitude

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SLIDE 23

Bzn distribution and standard deviation Bzn distribution and standard deviation

Bzn and Standard dev. (27 December 2005 - 13 February 2006)

2.032 2.034 2.036 2.038 2.04 2.042 2.044 2.046 12/27/2005 12/28/2005 12/29/2005 12/30/2005 12/31/2005 1/1/2006 1/2/2006 1/3/2006 1/4/2006 1/5/2006 1/6/2006 1/7/2006 1/8/2006 1/9/2006 1/10/2006 1/11/2006 1/12/2006 1/13/2006 1/14/2006 1/15/2006 1/16/2006 1/17/2006 1/18/2006 1/19/2006 1/20/2006 1/21/2006 1/22/2006 1/23/2006 1/24/2006 1/25/2006 1/26/2006 1/27/2006 1/28/2006 1/29/2006 1/30/2006 1/31/2006 2/1/2006 2/2/2006 2/3/2006 2/4/2006 2/5/2006 2/6/2006 2/7/2006 2/8/2006 2/9/2006 2/10/2006 2/11/2006 2/12/2006 2/13/2006 DAYS Bzn 0.00049 0.00249 0.00449 0.00649 0.00849 0.01049 0.01249 Standard deviation

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SLIDE 24

M8 ALGORITHM PREDICTION M8 ALGORITHM PREDICTION

(INTERMEDIATE (INTERMEDIATE-

  • TERM MIDDLE RANGE)

TERM MIDDLE RANGE)

(KOSSOBOKOV ET AL, 2007) (KOSSOBOKOV ET AL, 2007)

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SLIDE 25

M8 ALGORITHM PREDICTION M8 ALGORITHM PREDICTION

(KOSSOBOKOV ET AL, 2007) (KOSSOBOKOV ET AL, 2007)

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SLIDE 26

Bzn disturbances linked Bzn disturbances linked to to the seismic events the seismic events

Bzn and EQ. magnitude (01.01- 28.08.2006)

3.1 2.7 3.2 2.9 2.5 2.1 2.7 3.6 3.8 3.3 3.5 2.9 3.2 4.2 3.1 3 2.4 3 3.4 3.2 3.7 3.2 3.7 3.4 3.2 2.7 2.3 2.3 3.3 3.3 3.3 2.5 2.5 2.8 2.8 3.1 3.2 2.8 2.8 2.8 3.7 2.3 4.1 2.6 3.2 3.2 2.8 2.8 3.2 3 3.2 3 2.9 3 3.1 3.1 3.2 3.3 3.5 3.7 3.7 2.9 4.8 4.8 2.03 2.04 2.05 2.06 2.07 2.08

1/1/2006 1/2/2006 1/4/2006 1/9/2006 1/12/2006 1/15/2006 1/16/2006 1/19/2006 1/23/2006 1/27/2006 2/3/2006 2/4/2006 2/6/2006 2/8/2006 2/10/2006 2/18/2006 3/2/2006 3/5/2006 3/6/2006 3/12/2006 3/16/2006 3/17/2006 3/19/2006 3/22/2006 3/23/2006 3/25/2006 3/27/2006 4/5/2006 4/6/2006 4/8/2006 4/9/2006 4/10/2006 4/23/2006 4/30/2006 5/11/2006 5/12/2006 5/14/2006 5/15/2006 5/17/2006 5/21/2006 5/23/2006 5/26/2006 5/27/2006 5/30/2006 6/7/2006 6/8/2006 6/12/2006 6/16/2006 6/19/2006 6/25/2006 6/28/2006 6/30/2006 7/1/2006 7/4/2006 7/7/2006 7/8/2006 7/14/2006 7/25/2006 7/26/2006 8/1/2006 8/3/2006 8/12/2006 8/18/2006 8/27/2006

Days (EQ. mag. with depth < 50 km; EQ. mag. with depth >50 km) Bzn 1 2 3 4 5 6 EQ.magnitude

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SLIDE 27

Bzn disturbances linked Bzn disturbances linked to to the seismic the seismic events events

Bzn Distribution and EQ Magnitude (01.09.2006 - 26.01.2007) 2.05 2.052 2.054 2.056 2.058 2.06 2.062 2.064 2.066 2.068 2.07 2.072 2.074 2.076 2.078 9/1/2006 9/4/2006 9/7/2006 9/10/2006 9/13/2006 9/16/2006 9/19/2006 9/22/2006 9/25/2006 9/28/2006 10/1/2006 10/4/2006 10/7/2006 10/10/2006 10/13/2006 10/16/2006 10/19/2006 10/22/2006 10/25/2006 10/28/2006 10/31/2006 11/3/2006 11/6/2006 11/9/2006 11/12/2006 11/15/2006 11/18/2006 11/21/2006 11/24/2006 11/27/2006 11/30/2006 12/3/2006 12/6/2006 12/9/2006 12/12/2006 12/15/2006 12/18/2006 12/21/2006 12/24/2006 12/27/2006 12/30/2006 1/2/2007 1/5/2007 1/8/2007 1/11/2007 1/14/2007 1/17/2007 1/20/2007 1/23/2007 1/26/2007 Zile Bzn 3.5/139 3.1/81 4.3/126 3.0/73 3.7/100 3.4/104 3.6/150 3.8/148 3.0/6 3.0/130 3.2/130 3.0/20 3.2/10 4.2/120 3.0/115

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SLIDE 28

Bzn disturbances linked Bzn disturbances linked to to the seismic the seismic events events

2.048 2.049 2.05 2.051 2.052 2.053 2.054 2.055 2.056 2/1/2007 2/2/2007 2/3/2007 2/4/2007 2/5/2007 2/6/2007 2/7/2007 2/8/2007 2/9/2007 2/10/2007 2/11/2007 2/12/2007 2/13/2007 2/14/2007 2/15/2007 2/16/2007 2/17/2007 2/18/2007 2/19/2007 2/20/2007 2/21/2007 2/22/2007 2/23/2007 2/24/2007 2/25/2007 2/26/2007 2/27/2007 2/28/2007 Days Bzn 0.001 0.002 0.003 0.004 0.005 0.006 0.007 STdev STDEV Bzn

4.3/ 159km 4.0/ 107km

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SLIDE 29

Bzn disturbances linked Bzn disturbances linked to to the seismic the seismic events events

2.05 2.051 2.052 2.053 2.054 2.055 2.056 2.057 2.058 2.059 3 / 1 / 2 7 3 / 2 / 2 7 3 / 3 / 2 7 3 / 4 / 2 7 3 / 5 / 2 7 3 / 6 / 2 7 3 / 7 / 2 7 3 / 8 / 2 7 3 / 9 / 2 7 3 / 1 / 2 7 3 / 1 1 / 2 7 3 / 1 2 / 2 7 3 / 1 3 / 2 7 3 / 1 4 / 2 7 3 / 1 5 / 2 7 3 / 1 6 / 2 7 3 / 1 7 / 2 7 3 / 1 8 / 2 7 3 / 1 9 / 2 7 3 / 2 / 2 7 3 / 2 1 / 2 7 3 / 2 2 / 2 7 3 / 2 3 / 2 7 3 / 2 4 / 2 7 3 / 2 5 / 2 7 3 / 2 6 / 2 7 3 / 2 7 / 2 7 3 / 2 8 / 2 7 3 / 2 9 / 2 7 3 / 3 / 2 7 3 / 3 1 / 2 7 Days Bzn 0.0003 0.0013 0.0023 0.0033 0.0043 0.0053 0.0063 STdev STDEV Bzn

4.0/140 3.7/130

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SLIDE 30

Bzn disturbances linked Bzn disturbances linked to to the seismic the seismic events events

BZn

1.818 1.819 1.82 1.821 1.822 1.823 1.824 1.825 12/2/2007 12/3/2007 12/4/2007 12/5/2007 12/9/2007 12/10/2007 12/11/2007 12/12/2007 12/13/2007 12/14/2007 12/15/2007 12/16/2007 12/17/2007 12/18/2007 12/19/2007 12/20/2007 12/21/2007 12/22/2007 12/23/2007 12/24/2007 12/25/2007 12/26/2007 12/27/2007 12/28/2007 12/29/2007 12/30/2007 12/31/2007 Days Bzn 0.001 0.002 0.003 0.004 0.005 0.006 0.007 STDEV STDEV Bzn

3.0/112 3.2/117 3.1/131 3.2/102 3.0/124

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SLIDE 31

CONCLUSIONS: CONCLUSIONS: CONCLUSIONS: CONCLUSIONS:

  • Some days before an EQ occurred, the daily mean variation of the

normalized function Bzn has an anomalous behaviour marked by significant increase versus its normal distribution identified in non seismic conditions, as a result

  • f

the lithospheric conductivity changes produced by the dehydration of the rocks, associated with rupturing processes and fluid migration through faulting systems developed inside the Vrancea seismogenic volume and its surrounding areas;

  • Even if at present it is not possible yet to make any predictable

correlation between the magnitude of seismic event and the amplitude/shape of the Bzn parameter, for lack of sufficient data concerning seismic events (M>4), there is a chance to make a step forward on this way;

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SLIDE 32

Acknowledgments: Acknowledgments:

This study is supported by the Ministry of Education and Research, National Program “PN2”, Contract No.31-018/2007-2010

THANK YOU !