NHESS Natural Hazards and Earth System Sciences NHESS Nat. Hazards Earth Syst. Sci. 1684-9981 Copernicus Publications Göttingen, Germany 10.5194/nhess-3-249-2003 GPS detection of ionospheric perturbation before the 13 February 2001, El Salvador earthquake Plotkin V. V. 1 Institute of Geophysics, Koptyug Str. 3, 630090 Novosibirsk, Russia 31 08 2003 3 3/4 249 253 Copyright: © 2003 V. V. Plotkin 2003 This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 2.5 Generic License. To view a copy of this licence, visit https://creativecommons.org/licenses/by-nc-sa/2.5/ This article is available from https://nhess.copernicus.org/articles/3/249/2003/nhess-3-249-2003.html The full text article is available as a PDF file from https://nhess.copernicus.org/articles/3/249/2003/nhess-3-249-2003.pdf

A large earthquake of <i>M</i>6.6 occurred on 13 February 2001 at 14:22:05 UT in El Salvador. We detected ionospheric perturbation before this earthquake using GPS data received from CORS network. Systematic decreases of ionospheric total electron content during two days before the earthquake onset were observed at set of stations near the earthquake location and probably in region of about 1000 km from epicenter. This result is consistent with that of investigators, which studied these phenomena with several observational techniques. However it is possible, that such TEC changes are simultaneously accompanied by changes due to solar wind parameters and <i>K<sub>p</sub></i> -index.