2024-03-28T21:12:28Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/838922022-11-17T02:08:08Zhdl_2115_20039hdl_2115_116Identification of the infrasound signals emitted by explosive eruption of Mt. Shinmoedake by three-dimensional ray tracingSaito, HiroakiYamamoto, TetsuoNakajima, KensukeKuramoto, KiyoshiYamamoto, Masa-yuki453Mt. Shinmoedake, a part of the Mt. Kirishima cluster of volcanoes in Kyushu, Japan, erupted on 10 March 2018. Our infrasound sensor network located at a distance of more than 200 km from the source detected signals emitted by an explosive eruption of Mt. Shinmoedake. The arrival time of the signals is divided into three time intervals. To reveal how the observed infrasound signals propagated from the source to the sensors, we carry out three-dimensional ray tracing on the basis of the Hamilton equations including the vertical profiles of the temperature and wind around the ray path. We present formulas for calculating travel time and distance of infrasound from a source to an observation site and its turning altitude in the atmosphere. We have identified four kinds of signals, namely, the waves propagated in the troposphere undergoing multiple refraction and those refracting from the stratosphere, the mesosphere, and the lower thermosphere. Brief discussion is devoted to some of the unidentified signals.Acoustical Society of AmericaJournal Articleapplication/pdfhttp://hdl.handle.net/2115/83892https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/83892/1/J.%20Acoust.%20Soc.%20Am.149-1_591-598.pdf0001-4966Journal of the acoustical society of America14915915982021-01enginfo:doi/10.1121/10.0003366This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in The Journal of the Acoustical Society of America 149, 591-598 (2021) and may be found at https://doi.org/10.1121/10.0003366.publisher