SeismoAcoustic data analysis at I34MN Mongolia Songino

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Seismo-Acoustic data analysis at I34MNMongolia
- Songino
RESEARCH CENTRE OF ASTRONOMY AND GEOPHYSICS OF
MONGOLIAN ACADEMY OF SCIENCES
Ch. Bayarsaikhan, M. Ulziibat, A. Le Pichon, A.
Schlupp
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TOPICS

• DESCRIPTION OF MINE EXPLOSIONS AROUND I34MN
• SEISMO-ACOUSTIC DATA ANALYSIS
• STATISTICS AND VARIABILITY OF THE PROPAGATION
  PARAMETERS OF MINE EXPLOSIONS
• EVALUATION OF THE CELERITY
• SEASONAL VARIATION OF INFRASONIC DETECTION
• CONCLUSION

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I34MN INFRASOUND STATION IN SONGINO
Four infrasound sensors arranged as a triangular
array of 3 km aperture.
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WIND-NOISE REDUCING SYSTEM
6-15 dB _at_ 1-5 Hz
Wind noise
Signals
Gravel filters for wind noise reducing
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SEISMIC NETWORK
Seismic stations are equipped with 9
vertical component short-period seismometers and
one tree component short and long period seismic
sensors. The 10 seismic stations which form
double circled array with radius 1-3 km.
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Several large mines in the region routinely
generate explosions that are detected seismically
and with infrasound sensors. Mines are located
40-500 km from the seismic and infrasound array.
Baganuur coal mine, 180 km east of the array,
regularly produces 5-10 seismic detections per
week. Erdenet copper mine, which located 300 km
north-west produces several explosions every
week between 06-07 UTM time. Shariin gol Mine
181.1 km north-east. Borundur 302.2 km
south-east. Bagahangai 97.8 km east-south.
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IDENTIFYING AND LOCALIZATION OF QUARRY BLAST
USING SEISMIC DATA

• Real time processing and interpretation of
  seismic data from 15 seismic stations
• For identifying quarry blast we use waveforms,
  first motion, magnitude ratio of Ms and Ml.
• JADE and ONYX software are used for determining
  location and origin time of quarry blast.
• Results are stored in Oracle database.

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JADE
I arrivals
10 min
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ONYX
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SEISMIC LOCATIONS
Quarries identification
Baganuur
Erdenet
Others
Shariingol
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INFRASONIC DATA PROCESSING
JADE
WinPmcc
12 min

I arrivals

• Infra and seismic continuous real time data
  observation in JADE
• Automatic processing of Infrasonic data done by
  PMCC (0.02-4 Hz)
• Detailed processing of data is done manually
  using WinPmcc

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WinPmcc analysis different arrivals generated by
one explosion
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VARIABILITY OF THE PROPAGATION PARAMETERSERDENET
MINE
Average number of detection on 2000-2001 from
April to September no detection
Average azimuth on 2000-2001
Average trace velocity on 2000-2001
Azimuth 309-314
Celerity 0.30 0.34 km/s
Trace velocity 0.35 km/s
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VARIABILITY OF THE PROPAGATION PARAMETERSBAGANUUR
MINE
Average number of detection on 2000-2001 from
March to July no detection
Average azimuth on 2000-2001
Average trace velocity on 2000-2001
Azimuth 89-92
Celerity 0.25-0.30 km/s
Trace velocity 0.32-0.36 km/s
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CELERITY ESTIMATION
Celerity calculated using all explosion data C
0.25-0.30 km/s
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PHASE IDENTIFICATION
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SEASONAL VARIATION OF INFRASONIC DETECTION

• Seasonal variation of the detections are
  observed.
• Baganuur mine explosions are made not on fixed
  time
• in July and August we got 4 detections.
• Blue is detections of Infrasound
• Red is seismic detections

• For the Erdenet copper mine explosions, we have
  clear
• seasonal variation.
• Erdenet mine is making every week one series of
• explosions.

From November to February, 50 of the
explosions generate also infrasonic arrivals.
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STATISTICS ON ALL DETECTIONS AUTOMATICALLY
DETECTED BY PMCC
Azimuth distribution of infrasonic detection on
2000-2001
I
II
III
V
VI
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Statistics on the number of detections from the
automatic bulletin 0.1-4 Hz 2000-2001
VII
VIII
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The source of detection is mainly from mine
explosions, military activity, city noises and
also some time from large teleseismic events
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X
XII
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CONCLUSION

• Because of surrounding mines, explosions
  are detected by both
• Infrasound and Seismic stations. The
  seismo-acoustic synergy enables
• a fine analysis of the source.
• The detections of Infrasound station
  clearly depend on the
• season propagation effects and wind-noise
  variability.
• Future work automatic association of I and
  S arrivals for quarries location.