Micromorphological analysis of coastal sediments from Willapa Bay, Washington, USA: A technique for analysing inferred tsunami deposits

TY - JOUR

T1 - Micromorphological analysis of coastal sediments from Willapa Bay, Washington, USA

T2 - A technique for analysing inferred tsunami deposits

AU - Kilfeather, Aoibheann A.

AU - Blackford, Jeffrey J.

AU - van der Meer, Jaap J.M.

N1 - © Birkhauser Verlag, Basel, 2007

PY - 2007/3

Y1 - 2007/3

N2 - Tsunami deposits are provisionally distinguished in the field on the basis of anomalous sand horizons, fining-up and fining-landward, coupled with organic-rich, fragmented 'backwash' sediments. In this paper, micromorphological features of a sediment sequence previously interpreted as being of tsunami origin are described. These characteristics are shown to be consistent with the macro-scale features used elsewhere, but show additional details not seen in standard stratigraphies, including possible evidence for individual waves, possibly wave-magnitude progression, organic fragment alignment and intraclast microstructures. Although replication and more complete studies are needed, this analysis confirms the identification of a tsunami in Willapa Bay in ca.1700 AD, while demonstrating a widely applicable technique for confirming or refuting possible tsunami deposits.

AB - Tsunami deposits are provisionally distinguished in the field on the basis of anomalous sand horizons, fining-up and fining-landward, coupled with organic-rich, fragmented 'backwash' sediments. In this paper, micromorphological features of a sediment sequence previously interpreted as being of tsunami origin are described. These characteristics are shown to be consistent with the macro-scale features used elsewhere, but show additional details not seen in standard stratigraphies, including possible evidence for individual waves, possibly wave-magnitude progression, organic fragment alignment and intraclast microstructures. Although replication and more complete studies are needed, this analysis confirms the identification of a tsunami in Willapa Bay in ca.1700 AD, while demonstrating a widely applicable technique for confirming or refuting possible tsunami deposits.

KW - Cascadia subduction zone

KW - Micromorphology

KW - Thin sections

KW - Tsunami

KW - Washington

KW - Willapa Bay

UR - https://www.scopus.com/pages/publications/34147191680

U2 - 10.1007/s00024-006-0173-4

DO - 10.1007/s00024-006-0173-4

M3 - Article

AN - SCOPUS:34147191680

SN - 0033-4553

VL - 164

SP - 509

EP - 525

JO - Pure and Applied Geophysics

JF - Pure and Applied Geophysics

ER -