Search USGS⌕ Search

Geology topics

Research about South Carolina

Source-linked reports with geographic coverage including South Carolina.

At least 217 records · Page 12Linked to original sources
USGS2003

Simulation of Temperature, Nutrients, Biochemical Oxygen Demand, and Dissolved Oxygen in the Catawba River, South Carolina, 1996-97

Time-series plots of dissolved-oxygen concentrations were determined for various simulated hydrologic and point-source loading conditions along a free-flowing section of the Catawba River from Lake Wylie Dam to the headwaters of Fishing Creek Reservoir in South Carolina. The U.S. Geological Survey one-dimensional dynamic-flow model, BRANCH, was used to simulate hydrodynamic data for the Branched Lagrangian Transport Model. Waterquality data were used to calibrate the Branched Lagrangian Transport Model and included concentrations of nutrients, chlorophyll a, and biochemical oxygen demand in water samples collected during two synoptic sampling surveys at 10 sites along the main stem of the Catawba River and at 3 tributaries; and continuous water temperature and dissolved-oxygen concentrations measured at 5 locations along the main stem of the Catawba River. A sensitivity analysis of the simulated dissolved-oxygen concentrations to model coefficients and data inputs indicated that the simulated dissolved-oxygen concentrations were most sensitive to watertemperature boundary data due to the effect of temperature on reaction kinetics and the solubility of dissolved oxygen. Of the model coefficients, the simulated dissolved-oxygen concentration was most sensitive to the biological oxidation rate of nitrite to nitrate. To demonstrate the utility of the Branched Lagrangian Transport Model for the Catawba River, the model was used to simulate several water-quality scenarios to evaluate the effect on the 24-hour mean dissolved-oxygen concentrations at selected sites for August 24, 1996, as simulated during the model calibration period of August 23 27, 1996. The first scenario included three loading conditions of the major effluent discharges along the main stem of the Catawba River (1) current load (as sampled in August 1996); (2) no load (all point-source loads were removed from the main stem of the Catawba River; loads from the main tributaries were not removed); and (3) fully loaded (in accordance with South Carolina Department of Health and Environmental Control National Discharge Elimination System permits). Results indicate that the 24-hour mean and minimum dissolved-oxygen concentrations for August 24, 1996, changed from the no-load condition within a range of - 0.33 to 0.02 milligram per liter and - 0.48 to 0.00 milligram per liter, respectively. Fully permitted loading conditions changed the 24-hour mean and minimum dissolved-oxygen concentrations from - 0.88 to 0.04 milligram per liter and - 1.04 to 0.00 milligram per liter, respectively. A second scenario included the addition of a point-source discharge of 25 million gallons per day to the August 1996 calibration conditions. The discharge was added at S.C. Highway 5 or at a location near Culp Island (about 4 miles downstream from S.C. Highway 5) and had no significant effect on the daily mean and minimum dissolved-oxygen concentration. A third scenario evaluated the phosphorus loading into Fishing Creek Reservoir; four loading conditions of phosphorus into Catawba River were simulated. The four conditions included fully permitted and actual loading conditions, removal of all point sources from the Catawba River, and removal of all point and nonpoint sources from Sugar Creek. Removing the point-source inputs on the Catawba River and the point and nonpoint sources in Sugar Creek reduced the organic phosphorus and orthophosphate loadings to Fishing Creek Reservoir by 78 and 85 percent, respectively.

South Carolina↗
USGS2002

Structural and tectonic setting of the Charleston, South Carolina, region: Evidence from the Tertiary stratigraphic record

Eleven upper Eocene through Pliocene stratigraphic units occur in the subsurface of the region surrounding Charleston, South Carolina. These units contain a wealth of information concerning the long-term tectonic and structural setting of that area. These stratigraphic units have a mosaic pattern of distribution, rather than a simple layered pattern, because deposition, erosion, and tectonic warping have interacted in a complex manner through time. By generating separate structure-contour maps for the base of each stratigraphic unit, an estimate of the original basal surface of each unit can be reconstructed over wide areas. Changes in sea level over geologic time generate patterns of deposition and erosion that are geographically unique for the time of each transgression. Such patterns fail to persist when compared sequentially over time. In some areas, however, there has been persistent, repetitive net downward of upward movement over the past 34 m.y. These repetitive patterns of persistent motion are most readily attributable to tectonism. The spatial pattern of these high and low areas is complex, but it appears to correlate well with known tectonic features of the region. This correlation suggests that the tectonic setting of the Charleston region is controlled by scissors-like compression on a crustal block located between the north-trending Adams Run fault and the northwest-trending Charleston fault. Tectonism is localized in the Charleston region because it lies within a discrete hinge zone that accommodates structural movement between the Cape Fear arch and the Southeast Georgia embayment.

South Carolina↗
USGS2002

Effects of hatching time for larval ambystomatid salamanders

In aquatic communities, the phenology of breeding may influence species interactions. In the early-breeding marbled salamander, Ambystoma opacum , timing of pond filling may determine whether interactions among larvae are competitive or predatory. The objectives of our studies were to determine how time of egg hatching affected size, larval period, and survival to metamorphosis in A. opacum , and if early-hatching in A. opacum influenced the competitive and predator-prey relationships with smaller larvae of the mole salamander, Ambystoma talpoideum . Salamander larvae were reared from hatching through metamorphosis in large, outdoor enclosures located in a natural temporary pond in Aiken County, South Carolina, in two experiments. In study 1, we reared early- and late-hatching A. opacum larvae separately from hatching through metamorphosis. In study 2, we examined how early- versus late-hatching A. opacum affected a syntopic species, A. talpoideum . In general, early-hatching A. opacum were larger and older at metamorphosis, had greater survival, and left the pond earlier than late-hatching larvae. Ambystoma talpoideum reared in the presence of early-hatching A. opacum had lower survival than in controls, suggesting that A. opacum may predate upon A. talpoideum when they gain a growth advantage over later-hatching larvae. Our studies demonstrate that time of pond filling and phenology of breeding may influence population dynamics and alter the nature of relationships that develop among species.

South Carolina↗
USGS2002

Responses of coastal wetlands to rising sea level

Salt marsh ecosystems are maintained by the dominant macrophytes that regulate the elevation of their habitat within a narrow portion of the intertidal zone by accumulating organic matter and trapping inorganic sediment. The long-term stability of these ecosystems is explained by interactions among sea level, land elevation, primary production, and sediment accretion that regulate the elevation of the sediment surface toward an equilibrium with mean sea level. We show here in a salt marsh that this equilibrium is adjusted upward by increased production of the salt marsh macrophyte Spartina alterniflora and downward by an increasing rate of relative sea-level rise (RSLR). Adjustments in marsh surface elevation are slow in comparison to interannual anomalies and long-period cycles of sea level, and this lag in sediment elevation results in significant variation in annual primary productivity. We describe a theoretical model that predicts that the system will be stable against changes in relative mean sea level when surface elevation is greater than what is optimal for primary production. When surface elevation is less than optimal, the system will be unstable. The model predicts that there is an optimal rate of RSLR at which the equilibrium elevation and depth of tidal flooding will be optimal for plant growth. However, the optimal rate of RSLR also represents an upper limit because at higher rates of RSLR the plant community cannot sustain an elevation that is within its range of tolerance. For estuaries with high sediment loading, such as those on the southeast coast of the United States, the limiting rate of RSLR was predicted to be at most 1.2 cm/yr, which is 3.5 times greater than the current, long-term rate of RSLR.

South Carolina↗
USGS2002

Ground-water levels in the Floridan-Midville aquifer in the Breezy Hill area, Aiken and Edgefield counties, South Carolina, April 1999-November 2000

The Breezy Hill area in Aiken and Edgefield Counties of west-central South Carolina is a rapidly growing region in need of increasing amounts of ground water. From 1995 to 1998, the local water utility increased ground-water withdrawals in the Breezy Hill area from 1.4 to 2.1 million gallons per day to meet water-supply demands. As development continues, future demands for ground water will likely put stress on the surfaceand ground-water resources of the area. To address this issue, the U.S. Geological Survey, in cooperation with Aiken County, compiled and interpreted geologic and hydrologic data needed to map the ground-water system in the Breezy Hill study area. The Breezy Hill study area consists of four interfluvial areas comprising the regions between Horse and Little Horse Creeks, Little Horse and Hightower Creeks, Hightower Creek and Franklin Branch, and Franklin Branch and Mims Branch. Across the interfluvial areas, the average elevation of the water-level surface ranged from 200 to 480 feet above sea level, and the average saturated thickness of the Floridan-Midville aquifer ranged from less than 20 to 70 feet thick. A water-level contour map of the surface of the Floridan-Midville aquifer indicates that recharge to the aquifer occurs mainly within the interfluves. Recharge is derived principally from precipitation, although there is some potential for ground-water recharge from underlying crystalline rocks. Ground water discharges along the flanks of the interfluves into the bounding streams where the elevations of the ground water and streams coincide. From April 1999 to November 2000, calculated long-term normal precipitation totaled about 84.0 inches; however, actual recorded precipitation totaled 69.2 inches, representing about a 17.6 percent decrease in precipitation during this period. Published estimates of annual evapotranspiration range from 30 to 35 inches. A U.S. Geological Survey surface-water gaging station located near the center of the study area on Little Horse Creek monitors runoff from a drainage area of 26.6 square miles. Average annual flow for the station for water years 1990-2000 was 33.8 cubic feet per second. From April 1999 to November 2000, the monthly average flow was less than the average monthly flow for the longterm record, excluding December 1999 to March 2000 when no data were collected. Monthly average flow for Little Horse Creek exceeded the normal monthly flow during June and July 1999. Ground water in the Breezy Hill area is principally withdrawn from the unconfined Floridan- Midville aquifer. Ground-water withdrawals by the local water utility increased 37 percent from 1989 to 2000 (315.2 to 500 million gallons, respectively). From January 1999 to December 2000, the utility exceeded the long-term monthly average groundwater withdrawals for every month except September and December 2000. Calculated long-term monthly ground-water withdrawals by the utility for a 20-month period from April 1999 to November 2000 totaled 674 million gallons; however, actual ground-water withdrawals totaled 883 million gallons, which is 31 percent more than the long-term average ground-water withdrawals for the production wells. Published estimates of average annual ground-water recharge rates for the study area range from 13 to 15 inches per year. A base-flow recession analysis of streamflow data for Little Horse Creek provided an estimated recharge rate of 14.9 inches per year for the drainage area. Using an estimated average porosity ranging from 30 to 35 percent observed in sand-aquifer cores, the average annual recharge of 13 to 15 inches would cause a 3.6- to 4.1-foot water-level change to the saturated thickness of the aquifer, if applied instantaneously. The water-level declines observed in wells from April 1999 to November 2000 approximated an average decline of 4 feet. From November 1999 to November 2000, ground-water levels in six wells near utility pumping centers declined 2 to 5 feet. Long-term waterlevel declines of 10.27 and 11.50 feet were measured in two wells between May 1992 and April 2000, respectively.

South Carolina↗
USGS2002

Techniques for estimating the magnitude and frequency of floods in rural basins of South Carolina, 1999

Data from 167 streamflow-gaging stations in or near South Carolina with 10 or more years of record through September 30, 1999, were used to develop two methods for estimating the magnitude and frequency of floods in South Carolina for rural ungaged basins that are not significantly affected by regulation. Floodfrequency estimates for 54 gaged sites in South Carolina were computed by fitting the water-year peak flows for each site to a log-Pearson Type III distribution. As part of the computation of flood-frequency estimates for gaged sites, new values for generalized skew coefficients were developed. Flood-frequency analyses also were made for gaging stations that drain basins from more than one physiographic province. The U.S. Geological Survey, in cooperation with the South Carolina Department of Transportation, updated these data from previous flood-frequency reports to aid officials who are active in floodplain management as well as those who design bridges, culverts, and levees, or other structures near streams where flooding is likely to occur. Regional regression analysis, using generalized least squares regression, was used to develop a set of predictive equations that can be used to estimate the 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year recurrence- interval flows for rural ungaged basins in the Blue Ridge, Piedmont, upper Coastal Plain, and lower Coastal Plain physiographic provinces of South Carolina. The predictive equations are all functions of drainage area. Average errors of prediction for these regression equations ranged from -16 to 19 percent for the 2-year recurrence-interval flow in the upper Coastal Plain to -34 to 52 percent for the 500-year recurrenceinterval flow in the lower Coastal Plain. A region-of-influence method also was developed that interactively estimates recurrence- interval flows for rural ungaged basins in the Blue Ridge of South Carolina. The region-of-influence method uses regression techniques to develop a unique relation between flow and basin characteristics for an individual watershed. This, then, can be used to estimate flows at ungaged sites. Because the computations required for this method are somewhat complex, a computer application was developed that performs the computations and compares the predictive errors for this method. The computer application includes the option of using the region-of-influence method, or the generalized least squares regression equations from this report to compute estimated flows and errors of prediction specific to each ungaged site. From a comparison of predictive errors using the region-of-influence method with those computed using the regional regression method, the region-of-influence method performed systematically better only in the Blue Ridge and is, therefore, not recommended for use in the other physiographic provinces. Peak-flow data for the South Carolina stations used in the regionalization study are provided in appendix A, which contains gaging station information, log- Pearson Type III statistics, information on stage-flow relations, and water-year peak stages and flows. For informational purposes, water-year peak-flow data for stations on regulated streams in South Carolina also are provided in appendix D. Other information pertaining to the regulated streams is provided in the text of the report.

South Carolina↗
USGS2002

Magnitude and extent of arsenic and thallium concentrations in ground water and sediments at the Charleston Naval Complex, North Charleston, South Carolina, 1994-99

Water-quality samples were collected quarterly during 1994-99 from 604 wells screened in the surficial aquifer system beneath the Charleston Naval Complex, North Charleston, South Carolina. Arsenic and thallium were selected for analysis because concentrations of these metals in some wells consistently exceeded the established (2001) drinking water maximum contaminant levels of 10 and 2 micrograms per liter, respectively. The analysis was conducted to determine the magnitude and spatial distribution of arsenic and thallium in ground water at the Charleston Naval Complex and to quantify arsenic and thallium concentrations in a dated sediment core from Shipyard Creek marsh near the southern boundary of the Naval Complex. The surficial aquifer system beneath the Charleston Naval Complex consists of an unconfined upper surficial aquifer and a confined lower surficial aquifer. Hydraulic connection between the two aquifers is limited or nonexistent throughout the system at the Naval Complex. The Charleston Naval Complex is divided into nine operational units designated as zones A through I. Arsenic and thallium concentration data were compiled and interpreted for the two surficial aquifers within each zone. Mean arsenic (n=603) and thallium (n=604) concentrations were calculated for water samples from each well screened in the upper and lower surficial aquifers. In the upper surficial aquifer, mean arsenic concentrations ranged from 0.9 to 339 micrograms per liter and exceeded 10 micrograms per liter in 29 percent of the wells. In the lower surficial aquifer, mean arsenic concentrations ranged from 1.0 to 97.4 micrograms per liter and exceeded 10 micrograms per liter in 23 percent of the wells. The greatest number of water samples with mean arsenic concentrations exceeding 10 micrograms per liter were collected from wells in the upper surficial aquifer at zone E in the northwestern part of the study area. Well clusters, defined as three or more wells in a solid-waste management unit or area of concern, where the mean arsenic concentration exceeded 10 micrograms per liter, were identified in association with 12 sites in the upper surficial aquifer-solid-waste management unit 039 (a drum-storage area) in zone A; solid-waste management units 044 (coal-storage area) and 047 (burning dump) in zone C; solid-waste management unit 065 (lead-storage area) and area of concern 556 (dry docks 3 and 4) in zone E; areas of concern 609 (building 1346 gas station) and 613 (locomotive shop) in zone F; solid-waste management units 006 (public works storage yard) and 008 (oil sludge pit), and area of concern 709 (fuel-delivery system wells 12, 13, and 14) in zone G; and solid-waste management units 009 (closed landfill) and 196 (south landfill) in zone H. One well cluster was identified in the lower surficial aquifer in association with solidwaste management unit 009 (closed landfill) in zone H. Mean thallium concentrations in water from all wells ranged from less than 1.6 to 32.6 micrograms per liter in water samples from the upper surficial aquifer, and from less than 1.6 to 67.7 micrograms per liter in water samples from the lower surficial aquifer. Mean thallium concentrations equal to or greater than 10 micrograms per liter were present in water samples from 21 of 604 wells (3.5 percent). Of the 21 wells, 14 wells were located at solid-waste management unit 009 (closed landfill) in zone H near Shipyard Creek, 8 wells in the upper aquifer, and 6 wells in the lower aquifer. One well cluster where thallium exceeded 10 micrograms per liter was identified in association with solid-waste management unit 009 (closed landfill) in the upper surficial aquifer. Mean arsenic and thallium concentrations in water were calculated for all wells screened in one aquifer and located in a single zone, and are referred to as zone mean concentration in this report. Zone mean arsenic concentrations in all nine zones ranged from 3.2 to 18 micrograms per liter in water samples from the upper surficial aquifer and from 2.7 to 22 micrograms per liter in water samples from the lower surficial aquifer. Zone mean thallium concentrations in all nine zones ranged from 3.2 to 13 micrograms per liter in water samples from the upper surficial aquifer and from 3.2 to 14 micrograms per liter in water samples from the lower surficial aquifer. Ground-water samples rarely had elevated (equal to or greater than 10 micrograms per liter) concentrations of both arsenic and thallium. Water samples had coincident elevated arsenic and thallium concentrations in 10 wells in zone H, 1 well in zone A, and 1 well in zone B. Sediment quality at Shipyard Creek marsh was investigated by collecting an 11.8-foot -long sediment core (SYC-1) adjacent to zone I. The mean arsenic concentration in sediment samples from SYC-1 (n= 160) was 3.05 milligrams per kilogram plus or minus 0.92. The mean arsenic concentration and standard deviation calculated for SYC-1 sediment samples fall within the standard error for the background mean arsenic concentration reported for South Carolina sediments (1.5 milligrams per kilogram plus or minus 2. 7). All but one sample (core depth =50 inches) was less than the threshold-effects level of 7.24 milligrams per kilogram. Acid extracts of the sediment samples were analyzed for thallium concentration, but none were detected. These data indicate no obvious change in arsenic or thallium concentrations with depth in the core.

South Carolina↗
USGS2001

Shallow ground-water quality in an agricultural area of the lower coastal plain of South Carolina, 1997

Ground-water-quality samples were collected from 30 shallow monitoring wells located in agricultural areas of the lower Coastal Plain of South Carolina during the summer of 1997 as part of the U.S. Geological Survey National Water-Quality Assessment Program in the Santee River Basin and Coastal Drainages study unit. The wells were completed in sand to clayey sand sediments of the surficial aquifer and sampled one time for selected field properties, and nutrient, major ion, and pesticide concentrations. This report contains the results of the sampling effort.

South Carolina↗
USGS2001

Water resources data, South Carolina, water year 2000

Water resources data for the 2000 water year for South Carolina consist of records of stage, discharge, and water quality of streams; stage and contents of lakes and reservoirs; and ground-water levels. This report contains discharge records for 120 gaging stations; stage-only records for 39 gaging stations; stage and contents for 15 lakes and reservoirs; water quality for 38 gaging stations; and water levels for 46 observation wells. Also included are data for 52 crest-stage partial-record stations and discharge measurements at 7 miscellaneous sites. Additional water data were collected at various sites, not part of the systematic data collection program, and are published as miscellaneous investigations of water quality. These data represent that part of the National Water Data System collected by the U.S. Geological Survey and cooperating State and Federal agencies in South Carolina.

South Carolina↗
USGS2001

Water resources data, South Carolina, water year 2001

Water resources data for the 2001 water year for South Carolina consist of records of stage, discharge, and water quality of streams; stage and contents of lakes and reservoirs; and ground-water levels. This report contains discharge records for 121 gaging stations; stage-only records for 44 gaging stations; stage and co ntents for 14 lakes and reservoirs; water quality for 47 gaging stations; and water levels for 43 observation wells. Als o included are data for 52 crest-stage partial-record stations and discharge measurements at 7 miscellaneous sites. Add itional water data were collected at various sites, not part of the systematic data collection program, and are publish ed as miscellaneous investigations of water quality. These data represent that part of the National Water Data System co llected by the U.S. Geological Survey and cooperating State and Federal agencies in South Carolina.

South Carolina↗
USGS2000

Breeding season demography and movements of Eastern Towhees at the Savannah River Site, South Carolina

The Eastern Towhee ( Pipilo erythrophthalmus ) has undergone population declines across much of its range, especially in New England. Despite being a widespread and, at one time, a common species, relatively little is known about its natural history, ecology, or demographics. We conducted baseline research on Eastern Towhees at the Savannah River Site, South Carolina, in 1995 and 1996 to estimate breeding season survival rates, nest success rates, breeding densities, and daily movements. We also were interested in whether towhees had differences in survival and movement rates between young and mature managed pine stands. We found that survival rates during the breeding season of radio-marked towhees did not vary by sex or stand type. Daily nest success rates were very low [0.629 ± 0.088 (SE)] as a result of high predation levels. Abundance estimates adjusted for sampling effort differed between years. In 1995, the abundance estimate was significantly lower in mature stands (7.1 ± 0.47) than in young stands (9.6 ± 0.60) while in 1996, there was no different between mature stands (26.2 ± 5.67) and young stands (16.5 ± 3.39). Average daily movements by radio-marked towhees did not vary by sex or stand type. Movements among adjacent stands were common, and sometimes great distances.

South Carolina↗
USGS2000

Assessment of sedimentation in Crowders Creek, York County, South Carolina, 1999-2000

Sedimentation in Crowders Creek cove in Lake Wylie, located in York County, South Carolina, has restricted boat navigation and made a boat ramp unusable. To provide baseline information, the U.S. Geological Survey, in cooperation with the York County Council, collected bathymetric and bed-sediment data in the cove, and streamflow and suspended-sediment data in a free-flowing reach of Crowders Creek. Bathymetric data from a survey of the cove made in November 1999 were compared with bathymetric data derived from a 1973 U.S. Geological Survey topographic map. It was determined that at water-surface elevation of 568 feet, the volume of the cove available for water storage had decreased 90 percent, from 1.3 million cubic yards in 1973 to 135,000 cubic yards in 1999. Continuous water-level and streamflow data were collected at a U.S. Geological Survey stream-gaging station on Crowders Creek near Clover, South Carolina, for the period October 1, 1999, to April 30, 2000. Suspended-sediment concentration data were collected at four sites on February 14, 2000. The maximum instantaneous streamflow recorded during this event was 864 cubic feet per second, and the largest suspended-sediment load was calculated to be 2,120 tons per day. Bed-sediment samples were collected at four locations in the study area: one in the lower reach of Crowders Creek and three in the cove. These samples were analyzed for a total of 44 trace elements, 29 organochlorine pesticides, degradation products and polychlorinated biphenyls, and for particle-size distribution. None of the trace element concentrations exceeded guidelines for the concentrations above which adverse effects on stream biota are expected to occur. Two of 29 organochlorine pesticides were detected.p,p'-DDT at 11 micrograms per kilogram was detected at one site, and p,p'-DDE at 3.2 micrograms per kilogram was detected at another site. Particle-size analyses at these four sampling sites indicated that at least 60 percent of the sediments are smaller than 0.063 millimeter, which indicates the sediment is composed mostly of silts and clays.

South Carolina↗