Identifying tsunami deposits in the absence of sand

Simple item page
dc.contributor.authorChagué-Goff, Cen_AU
dc.contributor.authorJudd, Ken_AU
dc.contributor.authorGoff, JRen_AU
dc.contributor.authorGadd, PSen_AU
dc.contributor.authorFierro, Den_AU
dc.contributor.authorZawadzki, Aen_AU
dc.date.accessioned2016-04-20T00:17:17Zen_AU
dc.date.available2016-04-20T00:17:17Zen_AU
dc.date.issued2015-12-16en_AU
dc.date.statistics2016-03-20en_AU
dc.description.abstractTsunamis originating in South America are known to have affected Lyttelton Harbour, New Zealand, in the recent past. However, while there was clear evidence of inundation, in particular in 1960 and 2010, there was no report of any sand left behind. Our study aimed to search for evidence of these small historical tsunamis, in the absence of any visible sand layer. Shallow trenches revealed discontinuous layers of small grey mud clasts at various depths across the study area, most likely transported from the nearby harbour. The origin of these mud clast layers was investigated using sedimentological, geochemical and diatom analyses complemented by dating from 137Cs activity profiles and historical data. Subtle variations consistent with inclusions of marine mud such as a decrease in organic content and magnetic susceptibility and increases in geochemical markers (e.g. Ca, K, K/Rb, Si/Rb and Sr/Rb) were found in the sediment profile. Variations in diatom assemblages suggesting a marine influence were also recorded at similar depths, aligning with layers of mud clasts. Based on 137Cs activity profiles and historical data, these deposits were attributed to the 1960 Chile and 1964 Alaska tsunamis, and we also found evidence for an older deposit, possibly associated with the 1868 Arica tsunami. Sedimentary evidence for the 2010 Chile tsunami was not found at the study site, but our study revealed spatial variations in Ca, Cl and Sr concentrations that were inversely related to Ti concentrations. This was used to identify the landward extent of inundation by the 2010 event. We show that a broad multi-proxy analysis can distinguish even the subtle signatures of an inconspicuous deposit laid down by a small tsunami. © 2014 American Geophysical Union.en_AU
dc.identifier.citationChagué-Goff, C, Judd, K., Goff J. R., P., Gadd, P., Fierro, D., & Zawadzki, A. (2015). Identifying tsunami deposits in the absence of sand. Paper presented at the AGU Fall Meeting San Francisco, 14-18 December 2015.en_AU
dc.identifier.conferenceenddate18 December 2015en_AU
dc.identifier.conferencenameAGU Fall Meetingen_AU
dc.identifier.conferenceplaceSan Francisco, Californiaen_AU
dc.identifier.conferencestartdate14 December 2015en_AU
dc.identifier.govdoc6408en_AU
dc.identifier.otherNH33A-1893en_AU
dc.identifier.urihttps://agu.confex.com/agu/fm15/webprogram/Paper59828.htmlen_AU
dc.identifier.urihttp://apo.ansto.gov.au/dspace/handle/10238/6777en_AU
dc.language.isoenen_AU
dc.publisherAmerican Geophysical Unionen_AU
dc.subjectTsunamisen_AU
dc.subjectDepositsen_AU
dc.subjectNew Zealanden_AU
dc.subjectSedimentsen_AU
dc.subjectAquatic ecosystemsen_AU
dc.subjectGeochemical surveysen_AU
dc.titleIdentifying tsunami deposits in the absence of sanden_AU
dc.typeConference Presentationen_AU
Files
License bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Conference Publications