AUTHOR=Donciu Codrin , Serea Elena , Temneanu Marinel Costel TITLE=Frequency domain estimation method of the characteristic period of the P wave of earthquakes JOURNAL=Frontiers in Physics VOLUME=13 YEAR=2025 URL=https://www.frontiersin.org/journals/physics/articles/10.3389/fphy.2025.1496451 DOI=10.3389/fphy.2025.1496451 ISSN=2296-424X