Funding for this research was provided by:
Ministry of Education, Culture, Sports, Science and Technology (KAKENHI (A)(2) 10304033, New Earthquake Prediction Programm)
Text and Data Mining valid from 2019-09-27
Received: 10 March 2019
Accepted: 11 September 2019
First Online: 27 September 2019
: The authors declare that they have no competing interests.