Transcript Bayarsaikhan_ITW-2007 - Laboratory for Atmospheric Acoustics

Infrasound Technology Workshop Tokyo,
13-16 November 2007
Analysis of regional infrasound
signals at IMS infrasound array in
Mongolia
a RCAG/MAS P.O.B-152, Ulaanbaatar-51 Mongolia ([email protected])b CEA/DASE BP12, Bruyeres-le-Chatel, France ([email protected])
a RCAG/MAS P.O.B-152, Ulaanbaatar-51 Mongolia ([email protected])
b CEA/DASE BP12, Bruyeres-le-Chatel, France ([email protected])
ITW 2007 Tokyo, 13-16 November 2007
Content
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Description of mining explosions around I34MN
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Seismo-acoustic data analysis:
Erdenet Copper mining explosion
Baganuur Coal mining explosion
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Infrasound and seismic signal measurement
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Data processing and analysis
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Infrasound wave propagation characteristics
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Conclusion
ITW 2007 Tokyo, 13-16 November 2007
Explosion sites and recording stations
Erdenet
mining
Mining area
PS25
Ulaanbaatar
I34MN
Baganuur
mining
Mining area
Infrasound array
Mining
Seismic array
ITW 2007 Tokyo, 13-16 November 2007
Statistics analysis of quarry blast
Detected mining explosions between 2000 and 2005
Detected by seismic station
Detected by Infrasound station
260 Erdenet
343 Shivee
33 Shivee
70 Sharyn gol
114 Erdenet
1085 Baganuur
758 Sharyn gol
184 Boroo
Recorded at seismic PS25
stations and
analyzed by seismic data
50 Boroo
352 Baganuur
Recorded at infrasound I34MN
stations and analyzed by
PMCC automatic bulletin
ITW 2007 Tokyo, 13-16 November 2007
Detected infrasonic signals between 2000-2005
All detected infrasound signals as a function of time and
azimuth
(left histogram shows number of detected events)
Erdenet
copper mine
3070-3080
Baganuur coal
mine
930-940
ITW 2007 Tokyo, 13-16 November 2007
Characteristics of selected mining areas
In the Erdenet area, explosions occur once a week on each Friday
- Distance relative to the I34MN station ~ 216 km
- Scheduled explosions each week at 07-08 UTM
- Magnitude range – 2.0 – 2.5
The Baganuur mine makes series of explosions every week
- Distance relative to the I34MN station ~ 143 km
- Scheduled explosions every week at 02-12 UTM
- Magnitude range – 2.0 – 2.5
ITW 2007 Tokyo, 13-16 November 2007
Relocated events, an input for a new interpretation
Relocation results: explosions from the Baganuur and Erdenet mining
sites were reviewed and relocated by combination of seismic and
infrasound phase arrivals.
ITW 2007 Tokyo, 13-16 November 2007
Seismic and infrasound recordings from Erdenet copper mine
Seismo-acoustic ~11 min
Winter time (09 Jan 2004 07:09:33.77 )
ITW 2007 Tokyo, 13-16 November 2007
Seismo-acoustic ~11 min
Summer time (30 July 2004 05:47:31.27 )
ITW 2007 Tokyo, 13-16 November 2007
Examples of PMCC analysis
Infrasound recordings
I34MN: 216 km
Winter time
Duration: 32 sec
Nb of phase: 2
Summer time
Iw
Displays the distribution of detection
according in a Speed/Back Azimuths
radar plot (Erdenet)
Is
Iw
Detailed processing of data is done
manually using PMCC
results of Erdenet
ITW 2007 Tokyo, 13-16 November 2007
Seismic and infrasound recordings Baganuur coal mine
Seismo-acoustic ~8 min
The detected of winter time (13 Jan 2003 06:30:26.65)
ITW 2007 Tokyo, 13-16 November 2007
The detected of summer time (13 Jan 2003 06:30:26.65)
ITW 2007 Tokyo, 13-16 November 2007
Examples of PMCC analysis
Infrasound recordings
I34MN: 143 km
Summer time
Winter time
Duration: 30 sec
Nb of phase: 1
Iw
Displays the distribution of detection
according in a Speed/Back Azimuths
radar plot (Baganuur)
Iw
Detailed processing of data is done
manually using PMCC
results of Baganuur
ITW 2007 Tokyo, 13-16 November 2007
SEISMO-ACOUSTIC DATA ANALYSIS
Number of quarry blast used for analysis
Travel time distribution by distance, red
circles correspond to Baganuur and blue
circles are Erdenet
ITW 2007 Tokyo, 13-16 November 2007
Distribution travel time by azimuth
Graphics of travel times Vs azimuth
of Baganuur mining explosions
Graphics of travel times Vs azimuth
of Erdenet mining explosions
( Red circles are showing Summer time
Blue are winter time)
( Red circles are showing Summer time
Blue are winter time)
ITW 2007 Tokyo, 13-16 November 2007
Iw
Is
Is
Distribution of travel time by Julian
date, red circle are Baganuur
explosion and black circle are
Erdenet
Distribution of celerity by month,
green and blue dot are manual
measurement data of Baganuur and
Erdenet, pink and red squares are
mean of all data
We compared all manual measurements of infrasound data from Erdenet and
Baganuur mining sites by month and by travel time and date. The observed variation of
about 100 seconds is mainly due to seasonal dependence of atmospheric wind
characteristics.
ITW 2007 Tokyo, 13-16 November 2007
CONCLUSION
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Many seismic and infrasonic signals are observed daily. Nearly a
quarter of all seismic signals has associated infrasonic arrivals.
Most of them occur during local working hours. These observations
suggest that a great deal of the activity observed is man-made.
Many of the seismo-acoustic signals are located in the distance
range of 40 to 500 km from the IS34MN array. The efficiency of the
detection of these man-made seismo-acoustic events is largely
dependent on the regional infrasound propagation conditions
related to the sound velocity, the epicentral as well as the wind
force and direction.
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Additional work is needed in the interpretation and modeling of
seismic and infrasound signals.
THANK YOU
Conclusion
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The seasonal dependence of travel time is
mainly controlled by seasonal variations of
atmospheric wind force and direction. The
seasonal temperature variation has almost
no effect.
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Infrasound –ûí í¿¿äëèéí ñòàíöûã áîãèíî
õóãàöààãààð ñóóðèëëóóëààä sourceóóäûã òîäîðõîéëîõ áîëîìæûí òàëààð
(determine source of detection natural and
some noise
Question
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Continues work data analysis
Ýäãýýð ¿ð ä¿íãýýð….
2000-2005
2000-2001
2002-2003
2004-2005