Patterns of beach erosion and accretion due to jetty construction
are examined for the coast of Oregon. All jetty systems are
included with the exception of those on the Columbia River, making a
total of nine systems.
All evidence indicates that these areas of the Oregon coast are
experiencing a...
Siletz Bay is a drowned river valley filled with Holocene alluvial
and estuarine sediments and is separated from the ocean by a sand
spit 3.8 km in length. Since the area was settled by white man in the
1890's, the bay has apparently experienced rapid siltation, due to
increased farming...
Theoretical breaking criteria for progressive surface gravity
waves are examined, and laboratory and field experiments concerned
with breaking waves are reviewed with respect to the testing of these
breaking criteria. The measurements of Komar and Simmons are
presented here for the first time. Only three theoretical breaking
criteria have been...
Two beaches with significant differences in grain size and thus in beach profile morphology and response to wave conditions were studied on the Oregon coast. Gleneden Beach, just south of Siletz Spit and Lincoln City, has a median grain size of 0.36 mm (medium sand) and a steep beach face...
Field observations are made of the formation of backwash ripples
on the beachface, formed by undular hydraulic jumps generated by backwash
down the beach face colliding with wave bores. Measured ripple
wavelengths range from set averages of 48 to 70 cm. Within a particular
set of ripples there is a...
Heavy mineral compositions of sands from Oregon beaches,
rivers and sea cliffs have been determined in order to examine the
causes of marked along-coast variations in the beach-sand
mineralogy. The study area extends southward from the Columbia
River to the Coquille River in southern Oregon. The heavy-mineral
compositions were determined...
During the period 1970-76, Siletz Spit on the mid-Oregon coast
has suffered foredune erosion. This erosion is associated with high
wave conditions along the coast, produced by intense storms in the
North Pacific.
During the winter of 1972-73 and during January through March
1976 the erosion was particularly severe. The...