Ionospheric total electron content anomaly possibly associated with the April 4, 2010 Mw7.2 Mexico earthquake

Abstract

Abstract. Identifying ionospheric disturbances potentially related to an earthquake is a challenging work. Based on the ionospheric total electron content (TEC) data from the madrigal database at the Haystack Observatory, Massachusetts Institute of Technology, a new decomposition and nonlinear fitting method has been developed and applied in this work to extract the TEC disturbances that are potentially related to the Mw7.2 Mexico earthquake occurred on April 4 2010. By analyzing the TEC data for a long period of time (72 days) before and after the earthquake, we found that a unique TEC depletion occurred in the region around the epicenter on March 25. No other significant ionospheric TEC anomalies were identified in the 72-day period around the earthquake, except some TEC disturbances that appeared to be related to the geomagnetic activity between April 1 and 6, 2010. We further analyzed the TEC data from other magnetically quiet days, and no TEC anomaly like that occurred on March 25 was detected. The TEC data calculated from a first principles model SD-WACCM-X were also analyzed using the same method as that for the observational data. No TEC anomaly was found on March 25 from the model outputs either. Thus the source of the TEC anomaly on March 25 is unlikely from the lower atmosphere waves. In this study, we show the occurrence of TEC anomaly on March 25, 10 days before the Mw7.2 Mexico earthquake and this TEC anomaly may not be explained by lower atmosphere or geomagnetic activity forcing.

Statistical precursors of a strong earthquake on April 6, 2009 on the Apennine Peninsula

“…The INSPIRE project studied the physical processes and their effects in the ionosphere, which can be identified as earthquake precursors, with a detailed description of the methodology for determining ionospheric preseismic anomalies (Pulinets et al, 2021). Subtle fluctuations in Earth's ionosphere, a region of charged particles high above the surface, preceded the Baja California earthquake (Liu et al, 2022).…”

Reply to Dr. Angelo De Santis

“…286N, 115.295W). It is also called M7.2 Baja California earthquake (Yao et al, 2012;Jie and Guangmeng, 2013;Ulukavak and Yalcinkaya, 2017). The earthquake occurred on the northwest-trending strike-slip fault, which is along the principal plate boundary between the North American and Pacific plates, with a movement rate of 4.6 mm per year (Ulukavak and Yalcinkaya, 2017).…”