1. Seismo-Acoustic data analysis at I34MN Mongolia - Songino Seismo-Acoustic data analysis at I34MN Mongolia - Songino RESEARCH CENTRE OF ASTRONOMY AND GEOPHYSICS OF MONGOLIAN ACADEMY OF SCIENCES Ch. Bayarsaikhan, M. Ulziibat, A. Le Pichon, A. Schlupp

2. 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

3. Four infrasound sensors arranged as a triangular array of 3 km aperture. I34MN INFRASOUND STATION IN SONGINO

4. Wind noise 6-15 dB @ 1-5 Hz Signals WIND-NOISE REDUCING SYSTEM Gravel filters for wind noise reducing

5. 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. SEISMIC NETWORK

6. 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. …

9. 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.

10. ~10 min I arrivals JADE

11. ONYX

12. Others Baganuur Shariingol Erdenet SEISMIC LOCATIONS Quarries identification

13. 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 ~12 min INFRASONIC DATA PROCESSING JADEWinPmcc + I arrivals

14. WinPmcc analysis: different arrivals generated by one explosion

15. V ARIABILITY OF THE PROPAGATION PARAMETERS ERDENET MINE Average number of detection on 2000-2001 from April to September no detection Average azimuth on 2000-2001Average trace velocity on 2000-2001 Azimuth: 309-314 °Celerity: 0.30 – 0.34 km/sTrace velocity: 0.35 km/s

16. V ARIABILITY OF THE PROPAGATION PARAMETERS BAGANUUR MINE Average number of detection on 2000-2001 from March to July no detection Average azimuth on 2000-2001Average trace velocity on 2000-2001 Azimuth: 89-92 °Celerity: 0.25-0.30 km/sTrace velocity: 0.32-0.36 km/s

17. CELERITY ESTIMATION The distance to Baganuur coal mine is 150 km and travel time of infrasonic wave is 500-600 sec The distance to Erdenet copper mine is 300 km and travel time of infrasonic wave is 650-750 sec The distance to Shariingol coal mine is 180 km and travel time of infrasonic wave is 550-600 sec The distances to other coal mines are in 300 km range and travel time of infrasonic wave is 800-900 sec Celerity calculated using all explosion data C = 0.25-0.30 km/s

18. PHASE IDENTIFICATION

19. SEASONAL VARIATION OF INFRASONIC DETECTION For the Erdenet copper mine explosions, we have clear seasonal variation. Erdenet mine is making every week one series of explosions. 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 From November to February, ~50% of the explosions generate also infrasonic arrivals.

20. STATISTICS ON ALL DETECTIONS AUTOMATICALLY DETECTED BY PMCC Azimuth distribution of infrasonic detection on 2000-2001 Statistics on the number of detections from the automatic bulletin 0.1-4 Hz 2000-2001 The source of detection is mainly from mine explosions, military activity, city noises and also some time from large teleseismic events IIIIII IV VVI VIIVIIIIX X XI XII

21. 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.