Estimation of Depth and Charge Weight for a Shallow Underwater Explosion Using cut off Frequencies and Ray-Trace Modeling
Science Research
Volume 1, Issue 6, December 2013, Pages: 75-78
Received: Nov. 20, 2013; Published: Dec. 20, 2013
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So Gu Kim, Korea Seismological Institute, Goyang, 410-734, Republic of Korea
Yefim Gitterman, Geophysical Institute of Israel, P.O. BOX, 182, Lod, 71100, Israel
Orlando Camargo Rodriguez, University of Algarve, LARSyS, Campus de Gambelas, Faro, 8005-139, Portugal
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In this paper we utilized an additional forward model to estimate the detonation depth using normal modes (cutoff frequencies) to estimate the detonation depth and net explosive weight. With detonation depth the net explosive weight for a shallow underwater explosion could also be determined. The hydroacoustic wave propagation in shallow channel was confirmed via ray-tracing method. We found cutoff frequencies of the reflection off the ocean bottom to be 8.5 Hz, 25 Hz, and 43 Hz while the cutoff frequency of the reflection off the free surface to be 45 Hz including 1.01 Hz for the bubble pulse, and also found the cutoff frequency of surface reflection to well fit the ray-trace modeling. Our findings led us to the net explosive weight of the ROKS Cheonan to be approximately 136 kg TNT at a depth of about 8 m within an ocean depth of around 44 m.
Cutoff Frequency, Total Reflection, Ray-Trace Modeling, Cycle Distance, Bubble Pulse, Net Explosive Weight
To cite this article
So Gu Kim, Yefim Gitterman, Orlando Camargo Rodriguez, Estimation of Depth and Charge Weight for a Shallow Underwater Explosion Using cut off Frequencies and Ray-Trace Modeling, Science Research. Vol. 1, No. 6, 2013, pp. 75-78. doi: 10.11648/
S. G. Kim, and Y. Gitterman, "Underwater explosion (UWE) analysis of the ROKS Cheonan Incident," Pure and Applied Geophysics, vol. 170, pp. 547-560, 2013. DOI:10.1007/ s00024-012-0554-9.
S. G. Kim, "Forensic seismology and boundary element method application vis-à-vis the ROKS Cheonan underwater explosion," Journal of Marine Science and Application, vol. 12, pp. 422-433, 2013. DOI: 10.1007/ s11804-013-1213-y.
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