...Eileen Hemphill-Haley Abstract Fossil diatoms from four stratigraphic sections along the tidal Niawiakum River, southwestern Washington, provide an independent paleoecological test of a relative sea-level rise that has been attributed to subsidence during an inferred earthquake in the Cascadia...

... Ocean, Washington, USA. Red star marks the place where the photographs of panel b and c were shot; b , inner estuary: tidal flats of Niawiakum River (ebb tide); c , fresh core from tidal flats of Niawiakum River: interbedded light gray sandstone and dark gray organic-rich mud. The deposits were...

... to regions with higher long-term uplift rates and occur near late Pleistocene upper-plate structures such as the Coquille fault ( Kelsey et al., 1994 ). Tributary valleys of the lower Coquille River, formerly distal arms of a once broader estuary, preserve the longest record of buried marsh soils...

.... Open circles mark data sites. Figure 5. Buried soil from 1700, as exposed in cutbank section of Niawiakum River, Willapa Bay, Washington. Peat from 1700 is overlain by sandy layers interpreted to have been deposited by tsunami coincident with earthquake; sand is, in turn, overlain...

... site (MM) mentioned in text. Approximate southern limit of Juan de Fuca lobe of Cordilleran Ice Sheet was just south of Ozette Lake (OL) basin near present-day Quillayute River (QR) ( Heusser, 1973 ; Haugerud, 2021 ). Valley glaciers did not extend into the Ozette Lake watershed; limits shown...

...., 2013 ; Wang and Tréhu, 2016 ; Bilek and Lay, 2018 ), or a lack of preservation of coastal evidence for ruptures of a few hundred kilometers or less ( Nelson et al., 2006 ; Shennan et al., 2016 ; Hutchinson and Clague, 2017 ). Figure 2. Map of part of the lower Siuslaw River valley near...

... Leaders: Brian Atwater, U.S. Geological Survey at University of Washington; Corina Allen, Washington Geological Survey; Diego Melgar, University of Oregon Hardy participants will spend the day canoeing the Niawiakum River, viewing muddy signs of megathrust earthquakes. Low-tide exposures at Willapa Bay...