Examination of seismo-ionospheric anomalies before earthquakes of M w ≥ 5.1 for the period 2008–2015 in Oaxaca, Mexico using GPS-TEC

Acta Geophysica

article

Melgarejo-Morales, Angela¹  Vazquez-Becerra, G. Esteban¹  Millan-Almaraz, J. R.²  Pérez-Enríquez, R.³  Martínez-Félix, Carlos A.¹  Gaxiola-Camacho, J. Ramon⁴ 

[1] Faculty of the Earth and Space Sciences, Autonomous University of Sinaloa;Faculty of Physical-Mathematical Sciences, Autonomous University of Sinaloa;Center of Geoscience, National Autonomous University of Mexico;Department of Civil Engineering, Autonomous University of Sinaloa

关键词: GPS-TEC;    Seismic precursors;    Mexico;    Geomagnetic index and solar conditions;   

DOI  :  10.1007/s11600-020-00470-9

学科分类：地球科学(综合)

来源: Polska Akademia Nauk * Instytut Geofizyki

【 摘 要 】

Earthquakes are a major danger in a constantly growing society due to their imminent impact and power of destruction. Therefore, the idea of successfully forecasting an earthquake continues to motivate the multidisciplinary study of phenomena proposed as possible earthquake precursors such as ionospheric anomalies. In that sense, total electron content (TEC) has demonstrated to be an efficient parameter for investigating the state of the ionosphere by making use of the Global Positioning System receivers. In the present study, raw vertical TEC data obtained from the standard RINEX files of the GPS constellation are used to examine the state of the ionosphere during the occurrence of light to moderate earthquakes in Mexico from years 2008 to 2015 with the aim of search for possible ionospheric anomalies related to seismic activity. In order to evaluate the impact at the geomagnetic and ionospheric environments, the Geomagnetic Equatorial Dst index, which is considered to have a great influence on TEC during geomagnetic storm period, and solar activity parameters, have been considered. The results indicated that 17 (74%) of the studied events presented not quiet geomagnetic conditions for the days before the earthquake. Thus, the changes in VTEC are most likely related to geomagnetic anomalies which rules out its possible seismic origin. Contrariwise, 3 (13%) of the events presented geomagnetic anomalies the days after the earthquake. For the remaining 3 (13%) events, these presented particular characteristics, such as: not quiet geomagnetic condition for the earthquake day, geomagnetic anomalies throughout the period and the opposite.

【 授权许可】

Unknown