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Sixteen years of bathymetry and waves at San Diego beaches.
Sustained, quantitative observations of nearshore waves and sand levels are essential for testing beach evolution models, but comprehensive datasets are relatively rare. We document beach profiles and concurrent waves monitored at three southern California beaches during 2001-2016. The beaches include offshore reefs, lagoon mouths, hard substrates, and cobble and sandy (medium-grained) sediments. The data span two energetic El Niño winters and four beach nourishments. Quarterly surveys of 165 total cross-shore transects (all sites) at 100 m alongshore spacing were made from the backbeach to 8 m depth. Monthly surveys of the subaerial beach were obtained at alongshore-oriented transects. The resulting dataset consists of (1) raw sand elevation data, (2) gridded elevations, (3) interpolated elevation maps with error estimates, (4) beach widths, subaerial and total sand volumes, (5) locations of hard substrate and beach nourishments, (6) water levels from a NOAA tide gauge (7) wave conditions from a buoy-driven regional wave model, and (8) time periods and reaches with alongshore uniform bathymetry, suitable for testing 1-dimensional beach profile change models
Resonances in an evolving hole in the swash zone
Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of American Society of Civil Engineers for personal use, not for redistribution. The definitive version was published in Journal of Waterway, Port, Coastal, and Ocean Engineering 138 (2012): 299–302, doi:10.1061/(ASCE)WW.1943-5460.0000136.Water oscillations observed in a 10-m diameter, 2-m deep hole excavated on the foreshore just above the low-tide line on an ocean beach are consistent with theory. When swashes first filled the initially circular hole on the rising tide, the dominant mode observed in the cross-shore velocity was consistent with a zero-order Bessel function solution (sloshing back and forth). As the tide rose and swash transported sediment, the hole diameter decreased, the water depth inside the hole remained approximately constant, and the frequency of the sloshing mode increased according to theory. About an hour after the swashes first reached the hole, it had evolved from a closed circle to a semi-circle, open to the ocean. When the hole was nearly semi-circular, the observed cross-shore velocity had two spectral peaks, one associated with the sloshing of a closed circle, the other associated with a quarter-wavelength mode in an open semi-circle, both consistent with theory. As the hole evolved further toward a fully semi-circular shape, the circular sloshing mode decreased, while the quarter-wavelength mode became dominant.The Office of Naval Research, a National Security Science and Engineering Faculty Fellowship, a National Science Foundation Career award, and a National Defense Science and Engineering Graduate Fellowship provided support
Assimilation—On (Not) Turning White: Memory and the Narration of the Postwar History of Japanese Canadians in Southern Alberta
This essay explores understandings of “race” – specifically, what it means to be Japanese – of nisei (“second generation”) individuals who acknowledge their near complete assimilation structurally and normatively into the Canadian mainstream. In historically-contextualized analyses of memory fragments from oral-history interviews conducted between 2011-2017, it focusses on voices and experiences of southern Alberta, an area whose significance to local, national, continental, and trans-Pacific histories of people of Japanese descent is belied by a lack of dedicated scholarly attention. In this light, this essay reveals how the fact of being Japanese in the latter half of the twentieth century was strategically central to nisei lives as individuals and in their communities. In imagining a racial hierarchy whose apex they knew they could never share with the hakujin (whites), the racial heritage they nevertheless inherited and would bequeath could be so potent as to reverse the direction of the colonial gaze with empowering effects in individual engagements then and as remembered now. We see how the narration and validation of one’s life is the navigation of wider historical contexts, the shaping of the post-colonial legacy of Imperial cultures, as Britain and Japan withdrew from their erstwhile colonial projects in Canada
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