Magnetic record of extreme marine inundation events at Las Salinas site, Jalisco, Mexican Pacific coast

0458587 - GLÚ 2017 RIV US eng J - Článek v odborném periodiku
Černý, Jan - Ramírez-Herrera, M.-T. - Bógalo, M.-F. - Goguitchaichvili, A. - Castillo-Aja, R. - Morales, J. - Sanchez-Cabeza, J. A. - Ruiz-Fernandez, A. C.
Magnetic record of extreme marine inundation events at Las Salinas site, Jalisco, Mexican Pacific coast.
International Geology Review. Roč. 58, č. 3 (2016), s. 342-357. ISSN 0020-6814. E-ISSN 1938-2839
Institucionální podpora: RVO:67985831
Klíčová slova: anisotropy of magnetic susceptibility (AMS) * rock magnetic properties * tsunami * thermomagnetic curves * Mexican Pacific coast * variability
Kód oboru RIV: DE - Zemský magnetismus, geodézie, geografie
Impakt faktor: 2.262, rok: 2016

Extreme marine inundation events (i.e. severe storms and tsunamis) denote a major hazard to coastal communities around the globe. In order to assess this hazard, long-term (beyond the instrumental and historic records) information on the magnitude and frequency of these events is critical. The coastal sedimentary record, together with other proxies, is now being tested to distinguish and reconstruct evidence of ancient inundation events. Recent studies commonly use anisotropy of magnetic susceptibility (AMS) parameters without statistical evaluation of the lateral variability of sedimentary layers. Here, we provide results from tested sedimentary layers. Moreover, we discuss the most recent strategies to identify deposits produced by major inundation events using the full battery of rock magnetic properties of sediments in Careyes Bay on the Jalisco coast, Eastern Pacific, a tectonically active coast subject to hurricanes. Oriented samples of lagoonal sediments were taken from a dug pit at Las Salinas site. The sampled stratigraphic sequence was basically composed of an upper sand and lower clay units. The upper part of the Las Salinas profile shows a drop in magnetic susceptibility by 50%. Two distinct magnetic fabrics are clearly identified. Fabric from the upper part of the profile most probably reflects a sedimentary structure which was originated in a more dynamic environment than the magnetic fabric recognized in the lower part of the profile. Hysteresis parameters also show variation in behaviour between the upper and lower parts of the profile. We propose here that the origin of the upper sand unit at the study site is most probably related to an extreme marine inundation event.
Trvalý link: http://hdl.handle.net/11104/0258840