17:15 〜 19:15
[SSS13-P05] 震度頻度関係からの大地震発生頻度推定
キーワード：震度データ、頻度、前震・余震・群発の補正、統計解析
A disastrous earthquake struck the Noto Peninsula on January 1, 2024. However, the map created by the Headquarters for Earthquake Research Promotion (HERP) failed to emphasize the earthquake risks in that area. A governmental survey published in 2016 revealed that the ratio of people who believe they will experience severe natural hazards in the next 30 years is high on the Pacific Ocean side and low on the Japan Sea and East China Sea sides. Despite this, five out of eight JMA intensity 7 ground shakings have occurred on the Japan Sea and East China Sea sides. This discrepancy highlights a gap between public awareness of earthquake risks and the actual risks.
To address this gap, we constructed a model for estimating the rates of occurrences of Japan Meteorological Agency (JMA) intensity 6+ ground shakings based on the relationship between the rates of occurrences and intensities (RIRO). Our findings indicate that many sites on the Japan Sea and East China Sea sides have high rates of occurrences of JMA intensity 6+ ground shakings. Additionally, the slopes of the semilog RIRO differ among observation stations, meaning that areas with low rates of low-intensity shakings (e.g., intensity 3) do not necessarily have low rates of high-intensity shakings (e.g., intensity 6+).
We will present the contour maps of the estimated rates of occurrences of JMA seismic intensity 6+ or greater shakings, the contour maps of the slopes of semilog RIRO, and discuss the potential risks of strong ground shakings in various areas of our country. The software for calculating the RIRO and estimating the rates of occurrences is uploaded on GitHub and available to the public.
To address this gap, we constructed a model for estimating the rates of occurrences of Japan Meteorological Agency (JMA) intensity 6+ ground shakings based on the relationship between the rates of occurrences and intensities (RIRO). Our findings indicate that many sites on the Japan Sea and East China Sea sides have high rates of occurrences of JMA intensity 6+ ground shakings. Additionally, the slopes of the semilog RIRO differ among observation stations, meaning that areas with low rates of low-intensity shakings (e.g., intensity 3) do not necessarily have low rates of high-intensity shakings (e.g., intensity 6+).
We will present the contour maps of the estimated rates of occurrences of JMA seismic intensity 6+ or greater shakings, the contour maps of the slopes of semilog RIRO, and discuss the potential risks of strong ground shakings in various areas of our country. The software for calculating the RIRO and estimating the rates of occurrences is uploaded on GitHub and available to the public.