TITLE:
Meteorological Anomalies Based on Ground-Based AMeDAS Data for the 1995 Kobe Earthquake: Critical Natural Time Analysis
AUTHORS:
Masashi Hayakawa, Stelios M. Potirakis, Shinji Hirooka, Yasuhide Hobara
KEYWORDS:
Earthquake (EQ) Precursors, AMeDAS Data, Meteorological Parameters, Temperature/Humidity, ACP (Atmospheric Chemical Potential), Statistical Analysis, Critical Analysis, Natural Time (NT) Analysis
JOURNAL NAME:
Open Journal of Earthquake Research,
Vol.14 No.2,
April
30,
2025
ABSTRACT: Two meteorological quantities of T/Hum (T: temperature and Hum: relative humidity) and ACP (atmospheric chemical potential) of water molecules based on the “ground-based” AMeDAS (automated meteorological data acquisition system) “open” data of Japan Meteorological Agency have been utilized to explore a possibility of short-term earthquake (EQ) prediction. The target EQ is the famous 1995 Kobe EQ with magnitude of 7.3 on 17 January, 1995. Midnight (LT = 01 h) data of temperature and humidity at a particular station of Kobe, close to the EQ epicenter, have been analyzed, and we have found that there exists only a single and conspicuous peak in both quantities of T/Hum and ACP on the same day of 10 January, 1995 during the short-term EQ prediction window of one month before and two weeks after an EQ. Fortunately, during this short-term EQ prediction period, the geomagnetic and solar activity was extremely quiet, and so we think that the anomaly on this particular day, just one week before the EQ, is very likely to be a precursor to the EQ. Then, in order to find any definite causality relationship of this meteorological anomaly to the EQ, we have performed the critical analysis for the same datasets. We have applied the natural time (NT) analysis method to the daily-valued quantities of ACP and detrended T/Hum, and the NT analysis results revealed criticality in both quantities ~3 weeks before the 1995 Kobe EQ. This implies that the meteorological anomalies as a proxy of the exhalation of radon and charged aerosols from the lithosphere into the atmosphere are at the critical stage ~3 weeks before the EQ and so an anomaly in two meteorological quantities appeared one week before the EQ as a definite precursor to the EQ as suggested by this criticality.