scholarly journals EQUILIBRIUM FLOW AREAS OF TIDAL INLETS ON SANDY COASTS

1966 ◽  
Vol 1 (10) ◽  
pp. 38 ◽  
Author(s):  
Morrough P. O'Brien

The flow area of inlets on sandy coasts is a unique function of the tidal prism when equilibrium has been achieved. The size of material, the presence or absence of jetties, and the magnitude of general littoral drift does not appear to affect this equilibrium flow area within the accuracy of the data available. In the summer of 1929, the writer made a reconnaissance of the beaches and harbors of the Pacific Coast of the United States for the predecessor organization of the U. S. Beach Erosion Board. In tiie years preceding this study, many tidal inlets on the Worth Pacific Coast had been improved for navigation by constructing jetties, and the progress of these inlets towards stabilization was being followed through frequent hydrographic surveys, which were available for study. The obvious fact that large inlets were found at large bays and small inlets at small bays suggested the possibility that there might be a unique relationship between entrance area and tidal prism.

2019 ◽  
Vol 1 (2) ◽  
Author(s):  
Jonathan Akin French

Sandy inlets are in a dynamic equilibrium between wave-driven littoral drift acting to close them, and tidal flows keeping them open. Their beds are in a continual state of suspension and deposition, so their bathymetry and even location are always in flux. Even so, a nearly linear relationship between an inlet’s cross-sectional flow area and the inshore tidal prism is maintained - except when major wind and/or runoff events act to close or widen an inlet. Inlet location can be stabilized by jetties, but dredging may still be necessary to maintain a navigable channel. Armoring with rock large enough to resist erosion can protect an inlet bed or river mouth from excessive storm flow erosion.  Armoring can also be used as a stratagem to close inlets.


2019 ◽  
Vol 1 (2) ◽  
Author(s):  
Jonathan Akin French

Sandy inlets are in a dynamic equilibrium between wave-driven littoral drift acting to close them, and tidal flows keeping them open. Their beds are in a continual state of suspension and deposition, so their bathymetry and even location are always in flux. Even so, a nearly linear relationship between an inlet’s cross-sectional flow area and the inshore tidal prism is maintained - except when major wind and/or runoff events act to close or widen an inlet. Inlet location can be stabilized by jetties, but dredging may still be necessary to maintain a navigable channel. Armoring with rock large enough to resist erosion can protect an inlet bed or river mouth from excessive storm flow erosion.  Armoring can also be used as a stratagem to close inlets.


2021 ◽  
Vol 33 (2) ◽  
pp. 382-411
Author(s):  
Chris Madsen

Henry Eccles, in classic studies on logistics, describes the dynamics of strategic procurement in the supply chain stretching from home countries to military theatres of operations. Naval authorities and industrialists concerned with Japanese aggression before and after Pearl Harbor looked towards developing shipbuilding capacity on North America’s Pacific Coast. The region turned into a volume producer of merchant vessels, warships and auxiliaries destined for service in the Pacific and Indian Oceans. Shipbuilding involved four broad categories of companies in the United States and Canada that enabled the tremendous production effort.


1990 ◽  
Vol 68 (12) ◽  
pp. 2539-2552 ◽  
Author(s):  
P. L. Wong ◽  
R. C. Anderson

Twelve species of shorebirds belonging to the families Charadriidae (N = 3) and Scolopacidae (N = 9) were infected with 11 species of Skrjabinoclava and there was little overlap of parasites between these two families of birds. Most Skrjabinoclava spp. are transmitted apparently in marine staging and (or) wintering areas of their hosts, as indicated by the presence of larval stages of six species. There was no evidence that transmission occurs on the breeding grounds in freshwater habitats. Skrjabinoclava tupacincai, found predominantly in sanderlings (Calidris alba (Pallas)), is transmitted on the Pacific (Washington, California, Chile) and Atlantic coasts (New Jersey) in winter and the Gulf of Mexico (Florida and Texas) in winter and spring. Skrjabinoclava myersi was found, with a single exception, only in sanderlings, and transmission is apparently restricted to coastal Washington and California in winter. Skrjabinoclava bakeri, found predominantly in western sandpipers (Calidris mauri Cabanis), is transmitted on the Pacific coast (California) and in the Gulf of Mexico in winter. Skrjabinoclava morrisoni and Skrjabinoclava pusillae were found mainly in semipalmated sandpipers (Calidrispusilla (L.)). Both parasites are transmitted in the Gulf of Mexico in spring, but S. morrisoni is also transmitted in the Bay of Fundy in fall. Skrjabinoclava inornatae, found mainly in willets (Catoptrophorus semipalmatus (Gmelin)), is transmitted in Louisiana, Texas, and Peru in winter. Skrjabinoclava kritscheri was found only in marbled godwits (Limosafedoa (L.)), and it is suggested that infected birds collected in southern Alberta in spring acquired their infections while wintering along the Pacific coast of the United States. Skrjabinoclava hartwichi, found in black turnstones (Arenaria melanocephala (Vigors)) wintering in California and ruddy turnstones (Arenaria interpres (L.)) wintering in Peru, is transmitted along the Pacific coast of North America. Skrjabinoclava semipalmatae was found in semipalmated plovers (Charadrius semipalmatus Bonaparte) wintering in California. Skrjabinoclava wilsoniae was found in Wilson's plover (Charadrius wilsonia Ord) wintering in Texas and in a black-bellied plover (Pluvialis squatarola (L.)) migrating through southern Alberta in spring. Skrjabinoclava bartlettae was found in black-bellied plovers collected in southern Alberta in spring and Louisiana in winter.


2018 ◽  
Vol 87 (1) ◽  
pp. 150-172
Author(s):  
Katherine G. Morrissey

The following was the author’s presidential address at the annual meeting of the Pacific Coast Branch, American Historical Association, in Northridge, California, on August 4, 2017. The twentieth-century visual history of the U.S.-Mexico borderlands, la frontera, offers a rich set of representations of the shared border environments. Photographs, distributed in the United States and in Mexico, allow us to trace emerging ideas about the border region and the politicized borderline. This essay explores two border visualization projects—one centered on the Mexican Revolution and the visual vocabulary of the Mexican nation and the other on the repeat photography of plant ecologists—that illustrate the simultaneous instability and power of borders.


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