Development of the AMS method for unconsolidated sediments. Application to tsunami deposits

New sedimentary and geomorphic evidence of tsunami flooding related to an older events along the Tangier-Asilah coastal plain, Morocco

“…It has been demonstrated that the mean orientation of the grain's long axis (and thus the maximum tensor axis, Kmax), is parallel to low direction for moderate currents and settling from suspension. For stronger currents with dominant traction (bed load), the long axis of prolate particles (Kmax) tends to be orientated perpendicular to low direction (see review in Wassmer et al 2010;Wassmer and Gomez 2011;Kain et al 2014).…”

“…This plane reflects the characteristics (orientation and tilting) of the sediment fabric. Usually, solely the Kmax that parallels sand grains long axis is used to retrieve the sediment fabric and by then, the flow direction (Winkler et al 1997;Wassmer et al 2010;Wassmer and Gomez 2011).…”

Magnetic signature of the 22June 1932 tsunami deposits (Jalisco,MexicanPacific coast)

“…Sampling was performed in situ in the trench using standard acrylic cubes for magnetic property analyses. Cubes were inserted in the wall from the surface to the bottom of the trench sequentially with no intervals in between, to recover a complete section of the stratigraphic units ( Figure 1d) (for a detailed explanation of the technique see Wassmer and Gomez [2011], Ram ırez-Herrera et al [2012], and Cern y et al [2016]). The samples measured in this study are the same as those previously used for the AMS analysis by Ram ırez-Herrera et al [2014].…”

“…Since 2010, magnetic parameters such as magnetic susceptibility and anisotropy of magnetic susceptibility (AMS) have proved highly resolving in tsunami deposit research [ Font et al ., ; Wassmer et al ., ]. So far, several studies have applied these techniques in environments in which tsunami or paleotsunami deposits are present [ Ramírez‐Herrera et al ., ; Cuven et al ., ; Font et al ., ; Goguitchaichvili et al ., ; Schneider et al ., ; Černý et al ., ; Kain et al ., ; Wassmer and Gomez , ; Wassmer et al ., ].…”

“…Tsunami deposits are generated as a consequence of onshore inundation and backwash flow of large water bodies and exhibit many distinct characteristics, ranging from variations in the mineral composition and distribution to particle size range [Atwater and Moore, 1992;Dawson and Shi, 2000;Moore et al, 2006;Morton et al, 2007;Richmond et al, 2011;Ram ırez-Herrera et al, 2007, 2012Goto et al, 2015]. During the last decade, several multidisciplinary studies have been carried out to identify and characterize extreme inundation deposits [e.g., Kortekaas and Dawson, 2007;Ram ırez-Herrera et al, 2007, 2012Font et al, 2010Font et al, , 2013Engel and Br€ uckner, 2011;Wassmer and Gomez, 2011;Shanmugam, 2012;Cuven et al, 2013;Goto et al, 2014Goto et al, , 2015. Since 2010, magnetic parameters such as magnetic susceptibility and anisotropy of magnetic susceptibility (AMS) have proved highly resolving in tsunami deposit research [Font et al, 2010;Wassmer et al, 2010].…”