南海トラフの浅部スロー地震は日向灘、室戸岬沖、紀伊半島南東沖の3つの限られた地域でスポット的に発生します。しかし、南海トラフの浅部プレート境界に沿って沈み込む堆積物の（a–b）の値は、深さ10 km以浅においておおよその場合で正の値を示します。これは、プレート境界浅部において自発的に地震のようなすべり現象を起こすことが難しいことを意味します。浅部スロー地震発生には、図のようにプレート境界周辺に不均質に分布した間隙流体とその移動現象が重要です。それらの地域で、周期的な間隙流体の移動が発生することで… もっと読む
Following the 1923 Kanto earthquake in Japan, Japanese researchers noticed strong effects of surface geology (ESG) on seismic motion and began to quantify the site amplification factors (SAFs) associated with soft surface sediments. Kawase et al. (20… もっと読む
Takamatsu et al. (2023) reprocesses the daily station coordinates of Japan's GNSS observation network "GEONET" since 1996 based on the newly developed analysis strategy "F5". Processing under the global baseline network, they achieve millimeter level… もっと読む
The Planetary Material Sample Curation Facility3 of JAXA is responsible for initial description of valuable returned samples, publication of catalog data2, sample storage, and sample distribution to researchers worldwide. As part of curatorial works,… もっと読む
Equatorial spread F (ESF) occurs globally at low magnetic latitudes in the Earth’s nighttime ionosphere. ESF is well-known for its adverse effect on the propagation of radio waves affecting navigation, telecommunication, and scientific satellite syst… もっと読む
When we gaze out on the distant universe, we see billions of galaxies and we also see hundreds of billions of stars in our own galaxy, the Milky Way. Whether we observe in the narrow wavelength band accessible to our human eyes, or we expand our visi… もっと読む
Fournier et al. (2021) report on physics-based secular variation forecasts for the international geomagnetic reference field (IGRF). Analysis of satellite data from 2000 onwards reveals that IGRF forecasts are worse at times of fast geomagnetic chang… もっと読む
