open access

https://hdl.handle.net/2115/58810

Preseismic TEC Changes for Tohoku-Oki Earthquake : Comparisons Between Simulations and Observations

英語

Tohoku-Oki earthquake

2015-02

CHINESE Geoscience Union

Terrestrial atmospheric and oceanic sciences

26(1)

63-72

Heki (2011) reported that the Japanese Global Positioning System (GPS) dense network detected a precursory positive total electron content anomaly (TEC), with Delta TEC similar ~3 TECU, similar ~40 minutes before the Tohoku-Oki earthquake (Mw 9.0). Similar preseismic TEC anomalies were also observed in the 2010 Chile earthquake (Mw 8.8), 2004 Sumatra-Andaman (Mw 9.2) and the 1994 Hokkaido-Toho-Oki (Mw 8.3). In this paper we apply our improved lithosphere-atmosphere-ionosphere (LAI) coupling model to compute the TEC variations and compare the simulation results with the reported TEC observations. For the Tohoku-Oki earthquake simulations we assumed that the stressed associated current started similar ~40 minutes before the earthquake, linearly increased and reached its maximum magnitude at the time of the earthquake main shock. It is suggested that a dynamo current density of similar ~25 nA m(-2) is required to produce the observed Delta TEC similar ~3 TECU.

学術雑誌論文

Version of Record

1017-0839

2311-7680