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Research about Maryl

Source-linked reports with geographic coverage including Maryl.

At least 55 records · Page 3Linked to original sources
USGS1981

Sedimentary framework of the Potomac River estuary, Maryland

Analyses of seismic-reflection profiles, sediment cores, grab samples, and side-scan sonar records, along with previously collected borehole data, reveal the characteristics, distribution, and geologic history of the shallow strata beneath the Potomac River estuary. The lowermost strata are sediments of the Chesapeake Group (lower Miocene to lower Pleistocene) that crop out on land near the shore but are buried as much as 40 m below the floor of the estuary. The top of these sediments is an erosional unconformity that outlines the Wisconsinan valley of the Potomac River. This valley has a sinuous trend, a flat bottom, a relief of 15 to 34 m, and axial depths of 34 to 54 m below present sea level. During the Holocene transgression of sea level, the ancestral valley was filled with as much as 40 m of sandy and silty, fluvial-to-shallow estuarine sediments. The fill became the substrate for oyster bars in the upper reach and now forms most marginal slopes of the estuary. Since sea level approached its present position (2,000 to 3,000 yr ago), the main channel has become the locus of deposition for watery, gray to black clay or silty clay, and waves and currents have eroded the heterogeneous Quaternary sediments along the margins, leaving winnowed brown sand on shallow shoreline flats. Pb-210 analyses indicate that modern mud is accumulating at rates ranging from 0.16 to 1.80 cm/yr, being lowest near the mouth and increasing toward the head of the estuary. This trend reflects an increased accumulation of fine-grained fluvial sediments near the turbidity maximum, similar to that found in nearby Chesapeake Bay. The present annual accumulation of mud is about 1.54 million metric tons; the cumulative mass is 406 million metric tons.

Maryl↗
USGS1970

Temperature and water-quality conditions of the Patuxent River estuary, Maryland, January 1966 through December 1967

The effect of power plant cooling water in raising natural water temperatures at a location near the power plant on the Patuxent River estuary is clearly evident from thermograph records. Surface temperature at a station 333 m (1,000 ft) downstream from the discharge canal was raised an average of about 4 C, and at times by as much as 8 C. Temperature rises were greatest during the winter. Infrared imagery showed that elevated surface temperatures could be detected about 5.5 km (3 nautical miles) upstream at flood tide. Temperature profiles obtained from airborne radiation equipment revealed a complicated surface temperature pattern and also showed the effects of density differences and wind action on the steam-electric station (S.E.S.) effluent plume. Mean annual salinity for a 5-year period (1963–1967) was highest in 1966, about 12.3 ‰, and lowest in 1967, about 9.9‰. Dissolved oxygen values for 1966–1967 ranged from 3.2 to 15.6 mg/l, and saturation ranged from 55 to 152%. Turbidity levels were inversely related to salinity, with the highest annual, mean of 28 JCU (Jackson Candle Units) occurring in 1967, the lowest salinity year. The extreme tide range was 2.1 m (6.7 ft); mean water levels at the Patuxent Bridge were highest in summer and lowest in winter. Water stages are more affected by wind speed and direction than by flow in the river.

Maryl↗
USGS1967

Temperature and water-quality conditions for the period July 1963 to December 1965, Patuxent River Estuary, Maryland

Graphs and tables obtained from continuous records of surface-water temperature from five stations for the period july 1963 through December 1965 and of surface, salinity, dissolved oxygen, turbidity, tide-stage, wind data and bottom temperature from a single station are presented herein. Effects of powerplant cooling water on water temperature were obvious at a station near the plant's discharge point. Surface-water density at the Patuxent River Bridge varied from 1.0033 to 1.0127 with least change during the period May to September. Salinity ranged from 3 to 16.5 parts per thousand. Average salinity in the spring of 1965 was double that of spring 1964. Turbidity was high during the winter, and peak values were obtained during prolonged periods of high wind velocities. Dissolved oxygen values ranged from 386 to 15.0 parts per million, and percentage saturation of oxygen from 49 to 144 percent. The extreme tidal range was 5.7 feet; mean water levels were highest in summer and lowest in winter and spring.

Maryl↗