Nat. Hazards Earth Syst. Sci., 21, 1785–1806, 2021 https://doi.org/10.5194/nhess-21-1785-2021 © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License. Long-term magnetic anomalies and their possible relationship to the latest greater Chilean earthquakes in the context of the seismo-electromagnetic theory Enrique Guillermo Cordaro1,2, Patricio Venegas-Aravena1,3,4, and David Laroze5 1Observatorios de Radiación Cósmica y Geomagnetismo, Departamento de Física, FCFM, Universidad de Chile, Casilla 487-3, Santiago, Chile 2Facultad de Ingeniería, Universidad Autónoma de Chile, Pedro de Valdivia 425, Santiago, Chile 3Department of Structural and Geotechnical Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Vicuña Mackenna 4860, Macul, Santiago, Chile 4Research Center for Integrated Disaster Risk Management (CIGIDEN), Santiago, Chile 5Instituto de Alta Investigación, Universidad de Tarapacá, Casilla 7D, Arica, Chile Correspondence: Patricio Venegas-Aravena (
[email protected]) Received: 24 October 2020 – Discussion started: 26 November 2020 Revised: 29 April 2021 – Accepted: 10 May 2021 – Published: 11 June 2021 Abstract. Several magnetic measurements and theoretical in order to filter space influence. The FFT method confirms developments from different research groups have shown the rise in the power spectral density in the millihertz range certain relationships with worldwide geological processes. 1 month before each earthquake, which decreases to lower Secular variation in geomagnetic cutoff rigidity, magnetic values some months after earthquake occurrence. The cumu- frequencies, or magnetic anomalies have been linked with lative anomaly method exhibited an increase prior to each spatial properties of active convergent tectonic margins or Chilean earthquake (50–90 d prior to earthquakes) similar to earthquake occurrences during recent years.