Spectral tracks in the ionosphere: Fast Fourier Transform analysis of seismo-ionospheric coupling through GPS Total Electron Content variations
Yazarlar (4)
Doç. Dr. Seçil KARATAY Kastamonu Üniversitesi, Türkiye
Arş. Gör. Ali ÇINAR Kastamonu Üniversitesi, Türkiye
Prof. Dr. Feza Arikan Hacettepe Üniversitesi, Türkiye
Prof. Dr. Orhan Arikan Bilkent Üniversitesi, Türkiye
Makale Türü Açık Erişim Özgün Makale (SSCI, AHCI, SCI, SCI-Exp dergilerinde yayınlanan tam makale)
Dergi Adı Tectonophysics (Q2)
Dergi ISSN 0040-1951 Dergi Bilgileri (2026)
Dergi Tarandığı Indeksler
Makale Dili İngilizce Basım Tarihi 05-2026
Kabul Tarihi Yayınlanma Tarihi 05-05-2026
Cilt / Sayı / Sayfa 933 / 1 / 231240–0 DOI 10.1016/j.tecto.2026.231240
Makale Linki https://linkinghub.elsevier.com/retrieve/pii/S0040195126001745
UAK Araştırma Alanları
Eğitim Bilimleri
Özet
This study investigates seismo-ionospheric coupling through spectral analysis of Total Electron Content (TEC) variations using a specialized Fast Fourier Transform algorithm (IONOLAB-FFT). We analyze TEC data from dense GNSS networks across thirteen significant earthquakes (Mw 5.6-9.0) in diverse tectonic settings, including nine world events and four in Türkiye. Our analysis reveals consistent spectral patterns preceding earthquakes, characterized by systematic shifts toward lower dominant frequencies, narrowing bandwidths, and increasing durations as seismic events approach. These patterns show strong magnitude dependence: major earthquakes (Mw≥ 8.0) exhibit dominant frequencies of 0.3–0.4 mHz with detectable ionospheric anomalies 4–5 days before the main shock, while moderate events (Mw 6.0–7.0) display higher frequencies (0.7–0.8 mHz) with precursors evident only 1–2 days prior. Pre-earthquake ionospheric signatures progressively transform from patterns resembling geomagnetically quiet conditions to those characteristic of disturbed periods, despite the absence of significant geomagnetic activity. Frequency-duration relationships demonstrate increasingly strong negative correlations as earthquakes approach, with spatial analysis showing clear epicentral focusing of anomalies. Secondary frequency peaks emerge 2–3 days before major events, potentially indicating different phases of the preparation process. The consistent patterns identified across diverse tectonic settings suggest that ionospheric precursors reflect fundamental physical processes related to pre-seismic strain accumulation. This research …
Anahtar Kelimeler
Fast Fourier Transform | GNSS monitoring | GPS-TEC | Ionospheric precursors | Seismo-ionospheric coupling