A sea-level database for the Pacific coast of central North America. (1st April 2015)

• Record Type: Journal Article
• Authors: Engelhart, Simon E.; Vacchi, Matteo; Horton, Benjamin P.; Nelson, Alan R.; Kopp, Robert E.
• Is Part Of: Quaternary science reviews. Volume 113(2015)
• Page Start: 78
• Page End: 92
• Publication Date: 2015-04-01
• Subjects: Sea-level database -- Cascadia subduction zone -- Pacific North America -- Glacial isostatic adjustment -- Holocene; Geology, Stratigraphic -- Quaternary -- Periodicals; Stratigraphie -- Quaternaire -- Périodiques; 551.79
• DOI: 10.1016/j.quascirev.2014.12.001
• Languages: English
• ISSNs: 0277-3791

Abstract

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 ± 0.8 mm a −1 in southern British Columbia to rising at 1.5 ± 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. Highlights: A database of (un)published sea-level data for the Pacific coast of North America. 600 sea-level index points and 241 sea-level limiting points for the past 16 ka. Formerly glaciated sites show highstands of relative sea level. Sites beyond glaciated region demonstrate a continuous rise in relative sea level. Isostatic response to deglaciation continues in the late Holocene.