TY - JOUR
T1 - GT0 Explosion Sources for IMS Infrasound Calibration
T2 - Charge Design and Yield Estimation from Near-source Observations
AU - Gitterman, Y.
AU - Hofstetter, R.
N1 - Funding Information:
Many organizations and persons participated in the preparation of Sayarim calibration explosions, measurements and data processing. High-quality explosives in convenient packages were supplied by IMI Ltd. (I. Veksler) for the 2009 experiment, and by EMI Ltd. (Dr. D. Hershkovich) for the 2011 experiment. Elita Security Ltd. (S. Kobi) assembled the 2009 IMI charge with maximal concentration of explosives. The IDF Experiment Division (E. Stem-pler, Y. Hamshidyan) provided appropriate territory, logistics and near-source measurements, and assembled the 2011 ANFO charges with the optimal initiation/detonation scheme. The IDF Engineer Corps (Z. Savir) contributed to preparation of infrastructure for close-in measurements, and conducted crater parameters measuring and processing. GII personnel helped in logistics procedures, preparation and deployment of numerous near-source local observation systems, and in data processing and graphic presentation of air-blast data (U. Peled, N. Perelman). Thanks to our collaborators Dr. J. Bonner, Weston Geophysical Corporation, Dr. R. Waxler, the University of Mississippi and Dr. E. Marchetti, the University of Firenze, for supplementing data of close seismo-acoustic observations in 2011 experiment. Thanks to V. Pergament of Magnitogorsk State Technical University for assisting in the analysis of the pressure-distance relationship, to Dr. L. Evers, the Royal Netherlands Meteorological Institute (KNMI), for supplementing stratospheric winds modeling. Sayarim experiments were supported by the US Army SMDC in 2009 (M. Pickens), and PTS CTBTO in 2011 (Dr. L. Zerbo and Dr. J. Given). Research work of one of the authors (Y.G.) was supported by the Israel Ministry of Immigrant Absorption. We are thankful to anonymous reviewers for valuable comments, especially relating to additional aspects of the air-blast secondary shock delay application, and the analysis of seismic magnitudes.
PY - 2014/1/1
Y1 - 2014/1/1
N2 - Three large-scale on-surface explosions were conducted by the Geophysical Institute of Israel (GII) at the Sayarim Military Range, Negev desert, Israel: about 82 tons of strong high explosives in August 2009, and two explosions of about 10 and 100 tons of ANFO explosives in January 2011. It was a collaborative effort between Israel, CTBTO, USA and several European countries, with the main goal to provide fully controlled ground truth (GT0) infrasound sources, monitored by extensive observations, for calibration of International Monitoring System (IMS) infrasound stations in Europe, Middle East and Asia. In all shots, the explosives were assembled like a pyramid/hemisphere on dry desert alluvium, with a complicated explosion design, different from the ideal homogenous hemisphere used in similar experiments in the past. Strong boosters and an upward charge detonation scheme were applied to provide more energy radiated to the atmosphere. Under these conditions the evaluation of the actual explosion yield, an important source parameter, is crucial for the GT0 calibration experiment. Audio-visual, air-shock and acoustic records were utilized for interpretation of observed unique blast effects, and for determination of blast wave parameters suited for yield estimation and the associated relationships. High-pressure gauges were deployed at 100-600 m to record air-blast properties, evaluate the efficiency of the charge design and energy generation, and provide a reliable estimation of the charge yield. The yield estimators, based on empirical scaled relations for well-known basic air-blast parameters-the peak pressure, impulse and positive phase duration, as well as on the crater dimensions and seismic magnitudes, were analyzed. A novel empirical scaled relationship for the little-known secondary shock delay was developed, consistent for broad ranges of ANFO charges and distances, which facilitates using this stable and reliable air-blast parameter as a new potential yield estimator. The delay data of the 2009 shot with IMI explosives, characterized by much higher detonation velocity, are clearly separated from ANFO data, thus indicating a dependence on explosive type. This unique dual Sayarim explosion experiment (August 2009/January 2011), with the strongest GT0 sources since the establishment of the IMS network, clearly demonstrated the most favorable westward/eastward infrasound propagation up to 3,400/6,250 km according to appropriate summer/winter weather pattern and stratospheric wind directions, respectively, and thus verified empirically common models of infrasound propagation in the atmosphere.
AB - Three large-scale on-surface explosions were conducted by the Geophysical Institute of Israel (GII) at the Sayarim Military Range, Negev desert, Israel: about 82 tons of strong high explosives in August 2009, and two explosions of about 10 and 100 tons of ANFO explosives in January 2011. It was a collaborative effort between Israel, CTBTO, USA and several European countries, with the main goal to provide fully controlled ground truth (GT0) infrasound sources, monitored by extensive observations, for calibration of International Monitoring System (IMS) infrasound stations in Europe, Middle East and Asia. In all shots, the explosives were assembled like a pyramid/hemisphere on dry desert alluvium, with a complicated explosion design, different from the ideal homogenous hemisphere used in similar experiments in the past. Strong boosters and an upward charge detonation scheme were applied to provide more energy radiated to the atmosphere. Under these conditions the evaluation of the actual explosion yield, an important source parameter, is crucial for the GT0 calibration experiment. Audio-visual, air-shock and acoustic records were utilized for interpretation of observed unique blast effects, and for determination of blast wave parameters suited for yield estimation and the associated relationships. High-pressure gauges were deployed at 100-600 m to record air-blast properties, evaluate the efficiency of the charge design and energy generation, and provide a reliable estimation of the charge yield. The yield estimators, based on empirical scaled relations for well-known basic air-blast parameters-the peak pressure, impulse and positive phase duration, as well as on the crater dimensions and seismic magnitudes, were analyzed. A novel empirical scaled relationship for the little-known secondary shock delay was developed, consistent for broad ranges of ANFO charges and distances, which facilitates using this stable and reliable air-blast parameter as a new potential yield estimator. The delay data of the 2009 shot with IMI explosives, characterized by much higher detonation velocity, are clearly separated from ANFO data, thus indicating a dependence on explosive type. This unique dual Sayarim explosion experiment (August 2009/January 2011), with the strongest GT0 sources since the establishment of the IMS network, clearly demonstrated the most favorable westward/eastward infrasound propagation up to 3,400/6,250 km according to appropriate summer/winter weather pattern and stratospheric wind directions, respectively, and thus verified empirically common models of infrasound propagation in the atmosphere.
KW - Controlled surface chemical explosion
KW - IMS infrasound station calibration
KW - airblast secondary shock delay
KW - infrasound propagation
KW - yield estimation
UR - http://www.scopus.com/inward/record.url?scp=84895885713&partnerID=8YFLogxK
U2 - 10.1007/s00024-012-0575-4
DO - 10.1007/s00024-012-0575-4
M3 - Article
AN - SCOPUS:84895885713
SN - 0033-4553
VL - 171
SP - 599
EP - 619
JO - Pure and Applied Geophysics
JF - Pure and Applied Geophysics
IS - 3-5
ER -