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Research about Chesapeake Bay

Source-linked reports with geographic coverage including Chesapeake Bay.

177 records · Page 10Linked to original sources
USGS1978

Marine diatom sequence in Miocene strata of the Chesapeake Bay region, Maryland

The Calvert and Choptank Formations exposed along the west shore of Chesapeake Bay in Maryland have been correlated with strata of early and middle Miocene age. The stratigraphic ranges of marine diatom marker species indicate a distinct diatom sequence in the deposits. A few diatoms that mark deep-sea Miocene deposits are found sparingly in these shallow neritic assemblages. Seven diatom zones based on well-recognized events in the diatom biostratigraphy are proposed for the mid-Atlantic region of the eastern United States. A suggested correlation of these zones is made with some of the deep-sea diatom zonations in the Atlantic and Pacific Ocean basins.

Maryland↗
USGS1978

Exceedance probability-depth relationships of floods for Maryland streams west of Chesapeake Bay

A procedure is outlined for estimating the depths of floods of specified exceedance probabilities for Maryland streams west of the Chesapeake Bay. Data required for use of the estimating procedure are the stream's location in one of three flood-depth regions and the drainage area. Regression equations developed for depth estimation of the 50-, 20-, 10-, 2-, and 1-percent floods have standard errors of estimate of 19 to 25 percent for Region I, 22 to 36 percent for Region II, and 19 to 24 percent for Region III.

Maryland↗
USGS1977

Heavy-mineral variability in bottom sediments of the lower Chesapeake Bay, Virginia

Heavy minerals in bottom-sediment samples of the lower Chesapeake Bay show distribution patterns and interrelationships that denote characteristic mineral suites associated with defined geographic provinces. The Baymouth province has a garnet-hornblende-pyroxene suite, which is largely attributed to the influx of littoral and shelf sediments; the Eastern Shore province has a similar suite, derived largely from coastal erosion of the Eastern Shore peninsula. The Northern and Combined River provinces have a zircon-tourmaline-staurolite assemblage, which reflects derivation from an Appalachian Piedmont-Atlantic Coastal Plain sourceland. The Western Shore province is associated with a zircon-epidote-staurolite assemblage, apparently derived jointly from tributary influx and coastal erosion of the western shore. Factor analysis identified two major factors that account for 63% of the total variation in the relative amounts of the seven most common heavy minerals. The dominant factor (44%) is based on a zircon-hornblende-staurolite-pyroxene relationship, which indicates that mineral stability, as influenced by sediment maturity, is a major contributing factor. The second factor (19%) based on a tourmaline-epidote-staurolite-garnet relationship indicates that provenance is another major cause of heavy-mineral variability within the lower bay.

Virginia↗
USGS1974

Measurement in a marine environment using low cost sensors of temperature and dissolved oxygen

Continuous records of physical parameters of the marine environment are difficult as well as expensive to obtain. This paper describes preliminary results of an investigative program with the purpose of developing low cost time integrating measurement and averaging devices for water temperature and dissolved oxygen. Measurements were made in an estuarine area of the Chesapeake Bay over two week periods. With chemical thermometers average water temperature for the two week period was found to be equal to average water temperature measured with thermocouples plus or minus 1.0 C. The slow diffusion of oxygen through the semipermiable sides of plastic bottles permitted the use of water filled bottles to obtain averaged oxygen measurements. Oxygen measurements for two week averaging times using 500 ml polyethylene bottles were found to vary from conventionally measured and averaged dissolved oxygen by about 1.8 mg/l.

Chesapeake Bay↗
USGS1974

Oxidation effect on the analysis of iron in the interstitial water of recent anoxic sediments

Recent studies on the changes in composition of interstitial water during its separation from sediments 1-3 prompted us to evaluate the effect of squeezing on the concentration of ferrous iron within the interstitial water. Sediment samples were taken in northern Chesapeake Bay (38°56′ N and 76°25′ W) with a Benthos gravity corer. Layers of sediment were immediately extruded from the plastic coring tube and loaded into nylon squeezer barrels. The interstitial water was squeezed from the sediment through a 0.22 μm Millipore filter by the pressure of nitrogen acting against a rubber diaphragm 4 . The water drained directly into a calibrated test tube containing a solution of o-phenanthroline, buffered at pH 3.6, and the iron content was determined colorimetrically 5 . © 1974 Nature Publishing Group.

Chesapeake Bay↗
USGS1974

The 1973 distribution and abundance of breeding ospreys in the Chesapeake Bay

An aerial survey in association with several intensive ground surveys yielded the first estimate of the size of the osprey ( Pandion haliaetus carolinensis ) nesting population in Chesapeake Bay. The 1973 population was estimated at 1,450 ± 30 pairs, of which 713 were on the western shore and 737 on the eastern shore. A small percentage of nonbreeders (possibly 2-5 percent) may be included in this estimate. Only 31.7 percent of the population was nesting in trees; the remaining birds utilized duck blinds (28.7 percent), channel markers (21.8 percent), and miscellaneous man-made structures (17.8 percent). The geographical distribution of nesting ospreys has quite likely changed during the last several decades as suitable artificial nesting sites have become more available. Furthermore, limited evidence suggests that birds nesting on the man-made sites were more successful than those nesting in trees. This study provides a basis for monitoring future changes in numbers and distribution.

Maryland, Virginia↗
USGS1973

Phosphate in interstitial waters of anoxic sediments: Oxidation effects during sampling procedure

Oxidation during sampling procedures significantly decreases the inorganic phosphate concentrations of interstitial water rich in iron (II). All sampling and analytical procedures must be carried out in an inert atmosphere. Orthophosphate in the interstitial water of Cheaspeake Bay sediments, in equilibrium with vivianite, is a potential nutrient source for the overlying water.

Chesapeake Bay↗
USGS1970

An outbreak of fowl cholera in waterfowl on the Chesapeake Bay

An outbreak of fowl cholera ( Pasteurella multocida infection) occurred in waterfowl wintering on the Chesapeake Bay during February to March 1970. Losses were primarily confined to sea ducks: oldsquaws ( Clangula hyemalis ), white-winged scoters ( Melanitta deglandi ), golden-eyes ( Bucephala clangula ), and buffleheads ( Bucephala albeola ).

Maryland↗
USGS1968

Monthly surface-water inflow to Chesapeake Bay

This report presents a convenient and rapid means of estimating, on either a monthly or a yearly basis, the inflow from surface streams to Chesapeake Bay. The method was developed as a working base for the release entitled "Estimated stream discharge entering Chesapeake Bay" prepared by the U. S. Geological Survey in cooperation with the States of Maryland, Pennsylvania, and Virginia. This release, issued monthly beginning December 1967, is directed to the various groups who have need for such data in their studies of the environment and resources of the Bay. A copy of that release is included as an appendix to this report. In addition to the methodology used in making estimates of inflow, the report presents considerable data on drainage basins and on streamflow patterns. The report thus serves as a reference for those receiving the monthly release on current conditions. No account is taken of ground-water inflow or of rainfall on and evaporation from the water surface of the Bay. The years referred to herein are calendar years unless water years are specified.

Maryland, Pennsylvania, Virginia↗
USGS1915

Erosion and sedimentation in Chesapeake Bay around the mouth of Choptank River

With the unfolding of geologic knowledge during the last century the processes of denudation, transportation of sediments, and sedimentation have become better understood, and to some extent their relative effects in bringing about the present configuration of the earth's surface have been determined. The nature of these processes has been studied in many parts of the globe, but owing to the large size of the units affected and the slowness of the processes there has been little opportunity to collect quantitative data. Indeed, the data available are very largely conjectural, their degree of accuracy being only that of good guessing. However, with the advent of accurate topographic and hydrographic surveys, the first steps toward actual measurements of some of the many interesting surficial changes that are in progress have been taken, and it only remains for time and additional observations to afford opportunities for comparison. Resurveys, particularly by the United States Coast and Geodetic Survey, of parts of the eastern coast of the United States at different intervals have shown in many places marked changes of both shore line and sea bottom, as on Cape Cod, on Nantucket Island, and in Delaware Bay. Comparisons of this kind have so far been incidental to work in engineering and coast surveying, so that there has been little opportunity for the selection of localities particularly adapted to studies of erosion and sedimentation.

Maryland↗