Analysis of regional infrasound signals at IMS infrasound array in
Mongolia
a RCAG/MAS P.O.B-152, Ulaanbaatar-51a RCAG/MAS P.O.B-152, Ulaanbaatar-51 Mongolia Mongolia (([email protected]@rcag.url.mn))b b CEA/DASE BP12, Bruyeres-le-Chatel, France CEA/DASE BP12, Bruyeres-le-Chatel, France (([email protected]@cea.fr))a RCAG/MAS P.O.B-152, Ulaanbaatar-51a RCAG/MAS P.O.B-152, Ulaanbaatar-51 MongoliaMongolia ([email protected]) b b CEA/DASE BP12, Bruyeres-le-Chatel, France CEA/DASE BP12, Bruyeres-le-Chatel, France (([email protected]@cea.fr))
Infrasound Technology Workshop Tokyo, 13-16 November 2007
Content
Description of mining explosions around I34MN
Seismo-acoustic data analysis:
Erdenet Copper mining explosionBaganuur Coal mining explosion
Infrasound and seismic signal measurement
Data processing and analysis
Infrasound wave propagation characteristics
Conclusion
ITW 2007 Tokyo, 13-16 November 2007
Infrasound array
Explosion sites and recording stations
Mining Seismic array
I34MN
Ulaanbaatar
Erdenetmining
Baganuurmining
Mining area
Mining area
PS25
ITW 2007 Tokyo, 13-16 November 2007
Detected by seismic station
1085 Baganuur
184 Boroo758 Sharyn gol
343 Shivee 260 Erdenet
Detected by Infrasound station
352 Baganuur 50 Boroo
70 Sharyn gol33 Shivee
114 Erdenet
Recorded at seismic PS25 stations and
analyzed by seismic data
Statistics analysis of quarry blast
Detected mining explosions between 2000 and 2005
Recorded at infrasound I34MN stations and analyzed by PMCC automatic bulletin
ITW 2007 Tokyo, 13-16 November 2007
All detected infrasound signals as a function of time and azimuth
(left histogram shows number of detected events)
Detected infrasonic signals between 2000-2005
Erdenet copper mine
3070-3080
Baganuur coal mine
930-940
ITW 2007 Tokyo, 13-16 November 2007
In the Erdenet area, explosions occur once a week on each In the Erdenet area, explosions occur once a week on each FridayFriday - Distance relative to the I34MN station ~- Distance relative to the I34MN station ~ 216 km 216 km - Scheduled explosions each week at 07-08 UTM - Scheduled explosions each week at 07-08 UTM
- Magnitude range – 2.0 – 2.5- Magnitude range – 2.0 – 2.5
The Baganuur mine makes series of explosions The Baganuur mine makes series of explosions every weekevery week- - Distance relative to the I34MN station ~Distance relative to the I34MN station ~ 143 km 143 km
- Scheduled explosions every week at 02-12 UTM - Scheduled explosions every week at 02-12 UTM - Magnitude range – 2.0 – 2.5- Magnitude range – 2.0 – 2.5
Characteristics of selected mining areas
ITW 2007 Tokyo, 13-16 November 2007
Relocation results: explosions from the Baganuur and Erdenet mining sites were reviewed and relocated by combination of seismic and infrasound phase arrivals.
Relocated events, an input for a new interpretation
ITW 2007 Tokyo, 13-16 November 2007
Winter time (09 Jan 2004 07:09:33.77 )
Seismic and infrasound recordings from Erdenet copper mine
Seismo-acoustic ~11 min
ITW 2007 Tokyo, 13-16 November 2007
Summer time (30 July 2004 05:47:31.27 )
Seismo-acoustic ~11 min
ITW 2007 Tokyo, 13-16 November 2007
Iw
Iw
Sum
mer
tim
e
Detailed processing of data is done manually using PMCC
results of Erdenet
Displays the distribution of detection according in a Speed/Back Azimuths
radar plot (Erdenet)
Duration: 32 secNb of phase: 2
Examples of PMCC analysis Infrasound recordings
I34MN: 216 km
Win
ter
time
ITW 2007 Tokyo, 13-16 November 2007
Is
The detected of winter time (13 Jan 2003 06:30:26.65)
Seismic and infrasound recordings Baganuur coal mine
Seismo-acoustic ~8 min
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
Win
ter
time
Sum
mer
tim
e
Displays the distribution of detection according in a Speed/Back Azimuths
radar plot (Baganuur)
Detailed processing of data is done manually using PMCC
results of Baganuur
Duration: 30 secNb of phase: 1
Examples of PMCC analysis Infrasound recordings
I34MN: 143 km
Iw
Iw
ITW 2007 Tokyo, 13-16 November 2007
Number of quarry blast used for analysis Travel time distribution by distance, red circles correspond to Baganuur and blue
circles are Erdenet
SEISMO-ACOUSTIC DATA ANALYSIS
ITW 2007 Tokyo, 13-16 November 2007
Graphics of travel times Vs azimuthof Erdenet mining explosions
( Red circles are showing - Summer time
Blue are winter time)
Distribution travel time by azimuth
Graphics of travel times Vs azimuthof Baganuur mining explosions
( Red circles are showing - Summer time
Blue are winter time)
ITW 2007 Tokyo, 13-16 November 2007
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
Iw
Is
Is
CONCLUSIONCONCLUSION
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.
Additional work is needed in the interpretation and modeling of seismic and infrasound signals.
ITW 2007 Tokyo, 13-16 November 2007
THANK YOU
Conclusion
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.
Infrasound –ûí í¿¿äëèéí ñòàíöûã áîãèíî õóãàöààãààð ñóóðèëëóóëààä source-óóäûã òîäîðõîéëîõ áîëîìæûí òàëààð (determine source of detection natural and some noise
Question
Continues work data analysis Ýäãýýð ¿ð ä¿íãýýð….
2000-2005
2000-2001
2002-2003
2004-2005