[Paper Review] Atmosphere-Ionosphere Response to the M9 Tohoku Earthquake Revealed by Joined Satellite and Ground Observations. Preliminary results

Dimitar Ouzounov, С. А. Пулинец+6 more|arXiv (Cornell University)|May 13, 2011

Earthquake Detection and Analysis23 references18 citations

TL;DR

This study investigates atmospheric and ionospheric anomalies preceding the M9 Tohoku earthquake using combined satellite and ground-based observations. It identifies significant increases in outgoing longwave radiation, GPS-derived TEC, and ionosonde foF2 values starting March 8, 2011, indicating a positive correlation between pre-seismic ionospheric and atmospheric disturbances and the impending earthquake.

ABSTRACT

The recent M9 Tohoku Japan earthquake of March 11, 2011 was the largest recorded earthquake ever to hit this nation. We retrospectively analyzed the temporal and spatial variations of four different physical parameters - outgoing long wave radiation (OLR), GPS/TEC, Low-Earth orbit tomography and critical frequency foF2. These changes characterize the state of the atmosphere and ionosphere several days before the onset of this earthquake. Our first results show that on March 8th a rapid increase of emitted infrared radiation was observed from the satellite data and an anomaly developed near the epicenter. The GPS/TEC data indicate an increase and variation in electron density reaching a maximum value on March 8. Starting on this day in the lower ionospheric there was also confirmed an abnormal TEC variation over the epicenter. From March 3-11 a large increase in electron concentration was recorded at all four Japanese ground based ionosondes, which return to normal after the main earthquake. We found a positive correlation between the atmospheric and ionospheric anomalies and the Tohoku earthquake. This study may lead to a better understanding of the response of the atmosphere /ionosphere to the Great Tohoku earthquake

Motivation & Objective

• To investigate potential pre-seismic atmospheric and ionospheric precursors to the M9 Tohoku earthquake using multi-instrument data.
• To determine if anomalies in OLR, TEC, and ionosonde parameters correlate with the impending earthquake.
• To assess the spatial and temporal evolution of ionospheric disturbances in the days leading up to the main shock.
• To evaluate the consistency of anomalies across different observational platforms (satellite and ground-based).
• To contribute to the development of ionospheric-based earthquake prediction methods using multi-source data fusion.

Proposed method

• Utilized satellite-based outgoing longwave radiation (OLR) data to detect thermal anomalies in the atmosphere prior to the earthquake.
• Analyzed global positioning system (GPS) total electron content (TEC) data to monitor ionospheric electron density variations.
• Applied low-Earth orbit (LEO) satellite tomography to reconstruct three-dimensional electron density structures in the ionosphere.
• Processed ground-based ionosonde data to monitor critical frequency (foF2) variations at four Japanese stations.
• Spatiotemporal correlation analysis was performed to link anomalies in OLR, TEC, and foF2 to the epicentral region.
• Preliminary results were validated against seismic event timing and location, focusing on the period March 3–11, 2011.

Experimental results

Research questions

• RQ1 Did atmospheric thermal anomalies (measured via OLR) occur prior to the M9 Tohoku earthquake?
• RQ2 Were there significant deviations in ionospheric TEC values in the days before the main shock?
• RQ3 Did ground-based ionosondes detect abnormal foF2 values near the epicenter before the earthquake?
• RQ4 Is there a consistent spatiotemporal correlation between atmospheric and ionospheric anomalies and the impending seismic event?
• RQ5 Can multi-instrument observations reveal a coherent pre-seismic ionospheric response to a major earthquake?

Key findings

• A rapid increase in outgoing longwave radiation (OLR) was observed via satellite data on March 8, 2011, near the Tohoku earthquake epicenter.
• GPS/TEC data revealed a significant increase in electron density, peaking on March 8, 2011, over the epicentral region.
• Ionosonde measurements from four Japanese stations showed a large increase in critical frequency (foF2) from March 3 to 11, 2011, returning to normal after the main shock.
• Abnormal TEC variations were confirmed in the lower ionosphere over the epicenter starting March 8, 2011.
• A positive correlation was found between the observed atmospheric and ionospheric anomalies and the occurrence of the M9 Tohoku earthquake.
• The combined satellite and ground observations revealed consistent pre-seismic disturbances across multiple physical parameters, suggesting a possible ionospheric response to the impending earthquake.