scholarly journals COASTAL WAVE MODELING FOR JETTY REHABILITATION AT COOS BAY, OREGON

Author(s):  
Lihwa Lin ◽  
Zeki Demirbilek

Coos Bay Inlet, located on the Pacific coast of southwestern Oregon, is protected by dual jetties constructed in 1928. Because the inlet is exposing to high energy environment, both north and south jetties have deteriorated since the initial construction. Aging, erosion of foundation, lack of effective maintenance, and channel dredging in the past have accelerated the jetty deterioration. To ensure navigation safety, the U.S. Army Corps of Engineers is presently investigating the rehabilitation and redesign of jetties. This paper is focused on numerical storm wave modeling of the existing jetties to provide input forcing information to physical model and redesign of jetties.

1976 ◽  
Vol 1 (15) ◽  
pp. 60
Author(s):  
A.W. Garcia ◽  
H.L. Butler

The U. S. Army Corps of Engineers has as an objective of its research and development program the determination of better harbor design criteria for tsunami protection. A previous report (Houston, et. al., 1975b) addressed the subject of tsunami vulnerability of the Pacific Coast of the continental United States to tsunamis originating in the Aleutian Trench. That report determined the variation in tsunami amplitude as a function of coastal distance due to a standard uplift source at different locations in the Aleutian Trench. The present report is a continuation of that study and addresses the subject of tsunami vulnerability along the same stretch of coast to tsunamis originating in the Peru-Chile Trench. In addition, modifications to the numerical code used in the previous report allowed the simulation of the Chile tsunami of May 22, 1960.


2017 ◽  
Vol 65 (1-1) ◽  
pp. 147
Author(s):  
Catalina Gómez-Espinosa ◽  
Blanca Estela Buitrón-Sánchez

Taphonomic processes in a Pennsylvanian regional encrinite (Atokano), Sonora, Mexico. Crinoids have an extensive fossil record and were a major component in Paleozoic marine communities; encrinites are common crinoid accumulations where specimens are totally disarticulated from the Ordovician to the Jurassic. In Sonora, Mexico, the crinoid skeleton was altered during diagenesis and replaced by silica. The corrasion was high; the incrustation low and there is evidence of dissolution and compaction. This is a sedimentological type accumulation in a high energy environment of allochthonous organism transported in a debris flow, deposited below the storm wave base in an outer ramp. Our results can be correlated with regional encrinites prevalent in the Pennsylvanian cyclothems of North America. Rev. Biol. Trop. 65(Suppl. 1): S147-S159. Epub 2017 November 01. 


Author(s):  
G. W. Jones

Federal jurisdiction over wetlands under the Clean Water Act (“CWA”) 1 has always been difficult to delineate. Wetlands, by definition can be difficult to classify as either water or land. The CWA attempts to regulate these areas; it prohibits discharge of material without a permit into “navigable waters,” which are in turn defined in section 1362(7) of the CWA as the “waters of the United States.” The Army Corps of Engineers 2 is charged with granting permits, and must make the determination of whether or not certain areas of wetlands fall within the jurisdiction of the CWA.3 The Corps has interpreted the phrase “navigable waters” very broadly to include waters “which are currently used, or were used in the past, or may be susceptible to use in interstate or foreign commerce.”4 The tributaries of any of these “waters” also fall within the Corps’ jurisdiction.5 Intrastate waters are covered if their “use, degradation or destruction . . . could affect interstate or foreign commerce.”6 Wetlands “adjacent” to waters, such as those described above, except waters that are themselves wetlands, also clearly fall within federal jurisdiction under the CWA.7 Jurisdictional problems arise however when there are bodies of water or wetlands close to but not directly connected to navigable waters. These areas may still have significant impact on the neighboring navigable waters if a developer fills them in, or an industrial site discharges pollutants into them. Thus the Corps of Engineers has sought to regulate some of these wetland areas, in order to hold true to the CWA’s overall goals “to restore and maintain the chemical, physical, and biological integrity of the Nation’s waters.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Luis I. Quiroz ◽  
Luis A. Buatois ◽  
Koji Seike ◽  
M. Gabriela Mángano ◽  
Carlos Jaramillo ◽  
...  

AbstractThe distribution of trace-making organisms in coastal settings is largely controlled by changes in physicochemical parameters, which in turn are a response to different climatic and oceanographic conditions. The trace fossil Macaronichnus and its modern producers are typical of high-energy, siliciclastic foreshore sands in intermediate- to high-latitude settings characterized by cold-water conditions. However, it has been found in Miocene Caribbean deposits of Venezuela, prompting the hypothesis that upwelling of cold, nutrient-rich waters rather than latitude was the main control of its distribution. To test this hypothesis that was solely based on the fossil record, several trenches and sediment peels were made in two high-energy sand beaches having different oceanographic conditions along the Pacific and Caribbean coasts of the Central American Isthmus. As predicted, the burrows were found only in the highly productive waters of the Pacific coast of Costa Rica in connection with upwelling, while they were absent from the warm, oligotrophic waters of the Caribbean coast of Panama. This finding demonstrates that sometimes the past may be a key to the present, providing one of the few documented examples of reverse uniformitarianism.


2012 ◽  
Vol 1 (33) ◽  
pp. 109 ◽  
Author(s):  
Timothy W Kana ◽  
Haiqing Liu Kaczkowski

A 3.5 million cubic meter beach nourishment project was completed along 16 kilometers of shoreline at Nags Head, North Carolina, 32 kilometers south of the US Army Corps of Engineers Field Research Facility at Duck. The project is the largest locally-funded nourishment accomplished to date in the United States. Three ocean-certified hopper dredges and one cutterhead suction dredge constructed the project between May and October 2011. This paper discusses the planning, design, and initial performance of the project. Nags Head is exposed to high waves from the northeast which generate net southerly transport over the long term. A key design issue for the project was the large gradient in erosion rates from north to south. Fill sections were varied accordingly based on documented volume erosion rates and model simulations for the area. Permitting involved over five years of environ¬mental reviews because of the need to work during fair-weather summer months in the relatively high-energy setting. The design also built on prior work in connection with a federal nourishment project scheduled for the area if and when funds become available. Two offshore areas strategically located close to south Nags Head were utilized for construction which proceeded efficiently under summer waves until late August when Hurricane Irene impacted the area. The hurricane and fall northeast storms produced rapid adjustment of the construction profile but no net loss of sand from the project area. Post-project surveys show initial profile equilibration was largely confined to the inshore zone inside the 3.7 meter (m) [−12 foot (ft) NAVD] contour. Depth of closure at decadal scales is estimated to be −7.3 m (−24 ft NAVD).


2011 ◽  
Vol 1 (32) ◽  
pp. 52
Author(s):  
Orville T. Magoon ◽  
Donald D. Treadwell ◽  
Paul S. Atwood

To create and maintain a navigable entrance for small craft between the Pacific Ocean and the natural lagoon now referred to as Bodega Harbor, the construction of two rubble-mound jetties and the associated dredging of interior channels were authorized by the United States Congress in the late 1930s. The jetties were built by the United States Army Corps of Engineers in the early 1940s. Elements of the planning, design, construction, monitoring, and maintenance of the jetties are discussed herein.


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