Ionospheric perturbations in possible association with the 2010 Haiti earthquake, as based on medium-distance subionospheric VLF propagation data
- 1The University of Electro-Communications (UEC), Advanced Wireless Communications Research Center, 1-5-1 Chofugaoka, Chofu Tokyo 182-8585, Japan
- 2UEC, Research Station on Seismo Electromagnetics, Chofu Tokyo, Japan
- 3Centro de Radio Astronomia e Astrofisica, Universidade Presbiteriana Mackenzie, Escola de Engenharia, São Paulo, Brazil
- 4UEC, Graduate School of Informatics and Electronic Engineering, Chofu Tokyo, Japan
- 5Comisión Nacional de Investigación y Desarrollo Aeroespacial (CONIDA), Lima, Peru
- 6Information Systems Inc., Earthquake Analysis Laboratory, 4-8-15-405 Minami-Aoyama, Minato-ku, Tokyo 107-0062, Japan
Abstract. Ionospheric perturbations in possible association with the 2010 Haiti earthquake occurred on 12 January 2010 (with a magnitude of 7.0 and depth of 10 km) are investigated on the basis of subionospheric propagation data from the NAA transmitter on the east coast of the USA to a VLF receiving station in Peru. The local nighttime VLF amplitude data are extensively investigated during the period from the beginning of October 2009 to the end of March 2010, in which the trend (nighttime average amplitude), dispersion and nighttime fluctuation are analysed. It is found that a clear precursory ionosphere perturbation is detected just around New Years day of 2010, about 12 days before the main shock, which is characterised by the simultaneous decrease in the trend and the increases in dispersion and nighttime fluctuation. An additional finding might be the presence of the effect of the Earth's tide one and two months before the main shock, which can only be seen for a huge EQ.