Oceanography Commons^™

Determination Of Nutrient Levels And Proposed Predictive Models For Phosphate In The Lafayette River, Norfolk, Virginia, John R. Montgomery

OES Theses and Dissertations

The Lafayette River, an Urban, well-mixed estuarine embayment, was sampled from October, 1970 to January, 1972 for phosphate, nitrate, nitrite, oxygen, water temperature and salinity. The mean values found for these samples were: oxygen saturation from 69% to 106% nitrate from 0 to 4 microgram-atoms per liter, and salinity from 13 ‰ to 24 ‰. The mouth of the Elizabeth River to Hampton Roads as also sampled from May, 1971 to August, 1971. The Lafayette and Elizabeth Rivers were also sampled over a 24 hour period in the summer of 1971 and the Lafayette River again in the winter of …

Phytoplankton Distribution In Waters Off The Northeastern Coast Of The United States, Sharon H. Craft

Biological Sciences Theses & Dissertations

Abstract unavailable.

Surface Water Turbidity In The Entrance To Chesapeake Bay, Virginia, James R. Melchor

OES Theses and Dissertations

Seasonal and spatial variations in the surface water turbidity across the entrance to Chesapeake Bay, Virginia, have been monitored with an optical transmissometer for one year. The data indicate a suspended-sediment gradient across the entrance with higher turbidity on the south side. This condition suggests that the flooding and ebbing tidal currents are influenced by Coriolis force. Clearer ocean water is introduced into the bay on the north side; whereas highly turbid water from the major drainage systems exits on the south side. A salinity gradient with18 0/00 on the south side of the bay and approximately 32 0/00 on …

A Physical Hydrographic Study Of The Lafayette River, E. Glenn White

OES Theses and Dissertations

A basic investigation of the physical ~properties, temperature, density and current velocity, in the Lafayette River is presented. Graphs of the observations indicata a difference in salinity, density and current velocity- distributions after moderate to heavy rains from the graphs during a dry period. The changes in distribution indicate a change in the classification of the estuary from a type B/C, partially mixed estuary, to a type D, sectionally homogeneous estuary. The estuary is predominantly a well-mixed or sectionally homogeneous estuary.

Changes in salinity, temperature, density and current velocity over tidal cycles are discussed as well as tidal height data. …

The Influence Of The Summer Thermocline On Estuarine Classification In The Chesapeake Bay Entrance, William G. Weiss Jr.

OES Theses and Dissertations

The temperature, salinity, and sigma-t of 397 oceanographic stations taken in the entrance to Chesapeake Bay were plotted using a simple interpolation formula by the lBM 1130 computer. Each station was catalogued by position, tidal stage, season, and estuarine classification. Results indicated increased stratification during the ebb phase of all entrance stations regardless of season. Partially mixed conditions predominate. The influence of the summer thermocline on the stratification caused a slight increase in the summer stratification mean. However, statistical tests showed this summer increase to be insignificant at the 95% level. Detailed classification of tidal stage by estuarine type for …

A Graphic Analysis Of Current Velocity Salinity Density And Temperature During Periods Of Ebb And Flood In The Entrance To Thimble Shoals Channel, Stanley Hecker

OES Theses and Dissertations

A graphic analysis is presented of the observed patterns of longitudinal current velocity, salinity, density and temperature through a group of tidal cycles in Thimble Shoals Channel. Graphs of the properties indicate that this estuary passes through a sequence of estuarine types during a tidal cycle. In spite of this observation, the net non-tidal profiles of salinity are patterns of a partially mixed estuary.

The most noteworthy observation in this study was that longitudinal velocity was essentially constant throughout the water column at any increment of a tidal cycle as well as in the net non-tidal profile of the water …

Observations On The Hydraulic Regime Of The Ridge And Swale Topography Of The Inner Virginia Shelf, Barry W. Holliday

OES Theses and Dissertations

The Virginia inner shelf is dominated by southwest-trending sand ridges. Wavelengths are 2 to 4 km; amplitudes are up to 10 m; crests can be traced for up to 10 cm, Nearshore ridges trend southwest into the shore face and merge with it at depths as shoal as 5 m. The ridges have been examined by bathymetric mapping, grab sampling, coring, seismic profiling, SCUBA diving, and current monitoring. They are hemi-cylindrical sand bodies of recent age, resting on a pre-recent substrate. In troughs a thin, medium- to coarse-gained, pebbly lag veneers the substrate. Crests consist of a better sorted, medium- …

Analysis Of Littoral Transport By Wave Energy: Cape Henry, Virginia To The Virginia, North Carolina Border, Zvi Henry Weinman

OES Theses and Dissertations

An investigation of the rate of littoral transport by an analysis of wave energy for the area from Cape Henry, Virginia to the Virginia, North Carolina border is made. Wave refraction diagrams are done by digital computer. Total upcoast (northerly) transport is determined to be 2.05 x 10⁶ yds³/year. Total downcoast (southerly) transport is determined to be 1.07 x 10⁶ yds³/year. Net transport is determined to be 9.8 x 10⁵ yds³/year in an upcoast (northerly) direction. The values obtained are compared with those of similar areas. The general efficacy of the …

Nutrient-Density Relationships In The Western North Atlantic Between Cape Lookout And Bermuda, Unnsteinn Stefánsson, Larry P. Atkinson

CCPO Publications

A study of the nutrient-density relationships of Sargasso Sea water reveals a close correlation; Gulf Stream waters are anomalously higher and more variable in nutrients for a given density. Nutrient anomalies can be used in the same way as oxygen anomalies to map the distribution of Caribbean water in sections across the Gulf Stream. They show that contributions of Caribbean water to the Gulf Stream vary greatly from time to time. Oxidative ratios of ΔO : ΔN : ΔP = (−233) : 16.3 : 1.0 were derived from the correlation between oxygen anomalies and nutrients anomalies of Gulf Stream water …

An Evaluation Of An Electromagnetic Current Meter For Study Of Water Particle Motion, George Milton Hecker

OES Theses and Dissertations

A new sophisticated electromagnetic current meter was laboratory and field tested in a wide variety of applications, ranging from measurement of net bottom currents (primarily tidal origin) on the continental shelf, to horizontal and vertical components of wave induced orbital motion of waves with periods as small as one second.

These tests indicate that this instrument is capable of performing to at least the following specifications, subject to the comments which follow:

Speed range: Accuracy: Threshold: 0 to + 5 knots + 0.2 knots + 0.02 knots Response time: 0.25 sec. Direction: -+ 7 degrees Depth: '0 to 42 feet …

Erasure Of Sediment Surface Features By Mellita Quinquiesperforata (Leske), Walter Richard Boehmer

OES Theses and Dissertations

Erasure of sediment surface features by individuals of the species, Mellita guinguiesperforata, observed in this study suggests that all members of the sub-order, Scutellina, are able to erase sediment surface features. Sweep time, the time needed to erase the surface features of an area, depends on the population density, individual size, and speed of movement of the sand dollars. Assuming their pattern of movement as random, the following equation can be used to determine sand dollar sweep time,

T - 3.2 N^-0.76 (W / S) (A/ W² )^1.21

where T is sweep time, N is the …

Quaternary Sedimentation On The Inner Atlantic Shelf Between Cape Henry And Cape Hatteras: A Preliminary Report, Donald J. P. Swift, Gerald L. Shideler, Nicholas F. Avignone, Barry M. Holliday, Charles E. Dill Jr.

OES Faculty Publications

The coast of the Middle Atlantic Bight of North America's Atlantic shelf consists of a series of spit - barrier island systems attached on their northern ends to eroding headlands. It has been suggested that these barriers were generated as coastwise-prograding spits (Fisher, 1967) or alternatively as mainland beaches detached by the Holocene rise of sea level (Hoyt, 1967). The shore face before the barriers consists of fine, seaward-fining sand. Locally, it is corrugated by oblique-trending ridges with up to 8 metres of relief — see for instance CSGS Chart 1109. Beyond the shore face lies a vast submarine sand …

A Fluorescent Tracer Study At A Tidal Inlet (Rudee Inlet, Virginia), James W. Bunch

OES Theses and Dissertations

Patterns and approximate rates of littoral transport south of Rudee Inlet. Virginia were investigated with fluorescent tracers. Sand movement was traced under a variety of longshore current and wave conditions. Patterns of tracer dispersal reflected the importance of wave height, breaker angle, and longshore current velocity on modes of littoral transport. A direct relationship between angle of breaker incidence. generated longshore current. and direction of tracer sand movement was found. Onshore offshore paths were taken by tracer material during periods of weak longshore currents and small breaker angles while alongshore paths were followed by tracer material during strong longshore currents …

The Occurrence And Distribution Of Methane In The Marine Environment, Larry Philip Atkinson

OES Faculty Publications

The distribution of methane in several anoxic marine environments is described. Maximum concentrations observed were μ mole CH₄-C/liter. The distribution of methane seems to follow that of sulfide. The data indicate that methane is derived from organic compounds not containing nitrogen or phosphorus and that its formation is much slower than that of sulfide.

Diurnal Distribution Of Phytoplankton From A Single Station At The Mouth Of The James River, Harold G. Marshall

Biological Sciences Faculty Publications

Eight sets of water samples were taken to a depth of 36 ft. during a 24-hr. period. A homogeneity was found in the vertical distribution of the total phytoplankton in samples from 7 of the 8 hydro-casts. Skeletonema costatum and Asterionella japonica were the most numerous phytoplankters in every sample, with the majority of their counts each exceeding 500, 000 cells per liter.

Some Consequences Of The Decomposition Of Organic Matter In Lake Nitinat, An Anoxic Fjord, Francis A. Richards, Joel D. Cline, William W. Broenkow, Larry P. Atkinson

CCPO Publications

Observations in Lake Nitinat, an anoxic fjord on Vancouver Island, British Columbia, indicate that the large accumulations of ammonia, carbonates, phosphates, silicates, and sulfides in the deep water are the result of oxidative and fermentative decomposition of organic matter of planktonic origin, the reduction of sulfate ions, hydrolytic or other non-oxidative release (in the case of silicates), and the solution of carbonates (which also increases the alkalinity). Ammonia, sulfides, and silicates accumulate in the sulfide zone in direct proportion to each other, but some of the phosphate is probably released from the organic matter earlier than the other components, and …

The Distribution Of Phytoplankton Along A 140 Mile Transect In The Chesapeake Bay, Harold G. Marshall

Biological Sciences Faculty Publications

The composition of phytoplankton progressively changed in the surface samples taken between Norfolk, Virginia and Cambridge, Maryland. These was an inverse relationship between the numbers of phytoplankters and zooplankters in the transect samples. Vertical stratification of the plankton was studied at two 24-hr, stations at the Great Wicomlco and Patuxent Rivers. The vertical centers of zooplankton and phytoplankton populations fluctuated over the study period and evidence is given to support a grazing phenomenon. Large concentrations of nannoplankters were found in all the plankton samples taken and is attributed to the collection procedure using the Van Dorn sampler.