13:45 〜 14:00
[MIS04-06] Regional patterns in the re-occurrence of pre-earthquake signals in the atmosphere.
Case study for Noto M7.6 of Jan 1, 2024, and 6.8 M Niigata Chuetsu-Oki of Jul 16, 2007
キーワード： Noto earthquake, pre- earthquake, OLR, ACP, GPS/TEC, LAIC
We present a multi-parameter study of transient phenomena observed in the Earth's atmosphere-ionosphere environment plausibly associated with the latest earthquake in Japan- M7.6 Noto of Jan 1, 2024, compared with the M6.8 Niigata Chuetsu-Oki of Jul 16, 2007. Both earthquakes occurred in a close area along the coast of the Sea of Japan.
We collected Outgoing long-wavelength radiation (OLR) obtained from NPOESS. Atmospheric chemical potential (ACP) was obtained from NASA assimilation models and Electron density variations in the ionosphere via GPS Total Electron Content (GPS/TEC).
We applied OLR analysis for both earthquakes for 2004–2024, revealing an anomalous pattern with a ±2 sigma confidence level co-located with the epicenter. The first indication of the formation of a transient atmospheric anomaly in July was detected on Jul 8 (7 days) and for Boto on Dec 15 (16 days) before the mainshocks. We detect a similar rapid enhancement of radiation for both events, which could be explained by an anomalous flux of latent heat over the area of increasing tectonic activity. We study the ACP variations (every 3 h) using data from the GEOS assimilation model. The daily variation of ACP for Niigata Chuetsu-Oki shows the ACP absolute maximum on Jul 8 at 0600 LT, and for the Noto earthquake is Dec 27, 12:00 LT. The persistence of OLR and ACP anomalies on Jul 8, 2007 (for Niigata Chuetsu-Oki) and on Dec 27, 2024 (for Noto), indicate processes of a rapid build-up in the thermal field on the ground, and this coincides with other atmospheric changes—atmospheric temperature and humidity. Both earthquakes caused trouble in the maintenance of the world’s largest nuclear plant at Kashiwazaki-Kariwa without major reported incidents.
Our integrating data search reveals abnormal patterns inside the Dobrovolsky-Bowman estimating earthquake preparation zone. We observed a synergetic abnormal response of satellite OLR data, ACP, and GPS/TEC starting two to three weeks before the Noto M7.6 and the 6.8 M Niigata Chuetsu-Oki earthquakes. We show that by combining the near-space and ground data according to the physical concept of the Lithosphere-Atmosphere-Ionosphere Coupling (LAIC), we could identify, on a regional basis, the re-occurrence patterns of pre-earthquake signals in the atmosphere-ionosphere environment associated with the major seismicity (M6+).
We collected Outgoing long-wavelength radiation (OLR) obtained from NPOESS. Atmospheric chemical potential (ACP) was obtained from NASA assimilation models and Electron density variations in the ionosphere via GPS Total Electron Content (GPS/TEC).
We applied OLR analysis for both earthquakes for 2004–2024, revealing an anomalous pattern with a ±2 sigma confidence level co-located with the epicenter. The first indication of the formation of a transient atmospheric anomaly in July was detected on Jul 8 (7 days) and for Boto on Dec 15 (16 days) before the mainshocks. We detect a similar rapid enhancement of radiation for both events, which could be explained by an anomalous flux of latent heat over the area of increasing tectonic activity. We study the ACP variations (every 3 h) using data from the GEOS assimilation model. The daily variation of ACP for Niigata Chuetsu-Oki shows the ACP absolute maximum on Jul 8 at 0600 LT, and for the Noto earthquake is Dec 27, 12:00 LT. The persistence of OLR and ACP anomalies on Jul 8, 2007 (for Niigata Chuetsu-Oki) and on Dec 27, 2024 (for Noto), indicate processes of a rapid build-up in the thermal field on the ground, and this coincides with other atmospheric changes—atmospheric temperature and humidity. Both earthquakes caused trouble in the maintenance of the world’s largest nuclear plant at Kashiwazaki-Kariwa without major reported incidents.
Our integrating data search reveals abnormal patterns inside the Dobrovolsky-Bowman estimating earthquake preparation zone. We observed a synergetic abnormal response of satellite OLR data, ACP, and GPS/TEC starting two to three weeks before the Noto M7.6 and the 6.8 M Niigata Chuetsu-Oki earthquakes. We show that by combining the near-space and ground data according to the physical concept of the Lithosphere-Atmosphere-Ionosphere Coupling (LAIC), we could identify, on a regional basis, the re-occurrence patterns of pre-earthquake signals in the atmosphere-ionosphere environment associated with the major seismicity (M6+).