@article {2776,
	title = {Identifying the Greatest Earthquakes of the Past 2000 Years at the Nehalem River Estuary, Northern Oregon Coast, USA},
	journal = {Open Quaternary},
	volume = {6},
	year = {2020},
	month = {Feb-01-2021},
	abstract = {We infer a history of three great megathrust earthquakes during the past 2000 years at the Nehalem River estuary based on the lateral extent of sharp (<=3 mm) peat-mud stratigraphic contacts in cores and outcrops, coseismic subsidence as interpreted from fossil diatom assemblages and reconstructed with foraminiferal assemblages using a Bayesian transfer function, and regional correlation of 14C-modeled ages for the times of subsidence. A subsidence contact from 1700 CE (contact A), sometimes overlain by tsunami-deposited sand, can be traced over distances of 7 km. Contacts B and D, which record subsidence during two earlier megathrust earthquakes, are much less extensive but are traced across a 700-m by 270-m tidal marsh. Although some other Cascadia studies report evidence for an earthquake between contacts B and D, our lack of extensive evidence for such an earthquake may result from the complexities of preserving identifiable evidence of it in the rapidly shifting shoreline environments of the lower river and bay. Ages (95\% intervals) and subsidence for contacts are: A, 1700 CE (1.1 {\textpm} 0.5 m); B, 942{\textendash}764 cal a BP (0.7 {\textpm} 0.4 m and 1.0 m {\textpm} 0.4 m); and D, 1568{\textendash}1361 cal a BP (1.0 m {\textpm} 0.4 m). Comparisons of contact subsidence and the degree of overlap of their modeled ages with ages for other Cascadia sites are consistent with megathrust ruptures many hundreds of kilometers long. But these data cannot conclusively distinguish among different types or lengths of ruptures recorded by the three great earthquake contacts at the Nehalem River estuary.},
	keywords = {Bayesian transfer function, Cascadia subduction zone, Coseismic subsidence, earthquake hazards, Paleoseismology, salt-marsh stratigraphy, Sea-level changes, tidal foraminifera and diatoms},
	doi = {10.5334/oq.70},
	url = {http://www.openquaternary.com/articles/10.5334/oq.70/},
	author = {Nelson, Alan R. and Hawkes, Andrea D. and Sawai, Yuki and Engelhart, Simon E. and Witter, Rob and Grant-Walter, Wendy C. and Bradley, Lee-Ann and Dura, Tina and Cahill, Niamh and Horton, Ben}
}
@article {2597,
	title = {Differences in coastal subsidence in southern Oregon (USA) during at least six prehistoric megathrust earthquakes},
	journal = {Quaternary Science Reviews},
	volume = {142},
	year = {2016},
	month = {Jan-06-2016},
	pages = {143 - 163},
	abstract = {Stratigraphic, sedimentologic (including CT 3D X-ray tomography scans), foraminiferal, and radiocarbon analyses show that at least six of seven abrupt peat-to-mud contacts in cores from a tidal marsh at Talbot Creek (South Slough, Coos Bay), record sudden subsidence (relative sea-level rise) during great megathrust earthquakes at the Cascadia subduction zone. Data for one contact are insufficient to infer whether or not it records a great earthquake{\textemdash}it may also have formed through local, non-seismic, hydrographic processes. To estimate the amount of subsidence marked by each contact, we expanded a previous regional modern foraminiferal dataset to 174 samples from six Oregon estuaries. Using a transfer function derived from the new dataset, estimates of coseismic subsidence across the six earthquake contacts vary from 0.31 m to 0.75 m. Comparison of subsidence estimates for three contacts in adjacent cores shows within-site differences of <=0.10 m, about half the {\textpm}0.22 m error, although some estimates may be minimums due to uncertain ecological preferences for Balticammina pseudomacrescens in brackish environments and almost monospecific assemblages of Miliammina fusca on tidal flats. We also account for the influence of taphonomic processes, such as infiltration of mud with mixed foraminiferal assemblages into peat, on subsidence estimates. Comparisons of our subsidence estimates with values for correlative contacts at other Oregon sites suggest that some of our estimates are minimums and that Cascadia{\textquoteright}s megathrust earthquake ruptures have been heterogeneous over the past 3500 years.},
	keywords = {Cascadia subduction zone, Coseismic subsidence, Megathrust earthquakes, Paleoseismology, Salt-marsh foraminifera, Sea-level change, Transfer functions},
	issn = {02773791},
	doi = {10.1016/j.quascirev.2016.04.017},
	url = {https://doi.org/10.1016/j.quascirev.2016.04.017},
	author = {Milker, Yvonne and Nelson, Alan R. and Horton, Benjamin P. and Engelhart, Simon E. and Bradley, Lee-Ann and Witter, Robert C.}
}
@article {2596,
	title = {A sea-level database for the Pacific coast of central North America},
	journal = {Quaternary Science Reviews},
	volume = {113},
	year = {2015},
	month = {Jan-04-2015},
	pages = {78 - 92},
	abstract = {A database of published and new relative sea-level (RSL) data for the past 16 ka constrains the sea-level histories of the Pacific coast of central North America (southern British Columbia to central California). Our reevaluation of the stratigraphic context and radiocarbon age of sea-level indicators from geological and archaeological investigations yields 600 sea-level index points and 241 sea-level limiting points. We subdivided the database into 12 regions based on the availability of data, tectonic setting, and distance from the former Cordilleran ice sheet. Most index (95\%) and limiting points (54\%) are <7 ka; older data come mainly from British Columbia and San Francisco Bay. The stratigraphic position of points was used as a first-order assessment of compaction. Formerly glaciated areas show variable RSL change; where data are present, highstands of RSL occur immediately post-deglaciation and in the mid to late Holocene. Sites at the periphery and distant to formerly glaciated areas demonstrate a continuous rise in RSL with a decreasing rate through time due to the collapse of the peripheral forebulge and the reduction in meltwater input during deglaciation. Late Holocene RSL change varies spatially from falling at 0.7 {\textpm} 0.8 mm a-1 in southern British Columbia to rising at 1.5 {\textpm} 0.3 mm a-1 in California. The different sea-level histories are an ongoing isostatic response to deglaciation of the Cordilleran and Laurentide Ice Sheets.},
	keywords = {Cascadia subduction zone, Glacial isostatic adjustment, Holocene, Pacific North America, Sea-level database},
	issn = {02773791},
	doi = {10.1016/j.quascirev.2014.12.001},
	url = {https://doi.org/10.1016/j.quascirev.2014.12.001},
	author = {Engelhart, Simon E. and Vacchi, Matteo and Horton, Benjamin P. and Nelson, Alan R. and Kopp, Robert E.}
}
