scholarly journals Field studies of earthquake-induced, liquefaction-flowage features in the Charleston, South Carolina, area; preliminary report

1984 ◽  
Author(s):  
G.S. Gohn ◽  
R.E. Weems ◽  
S.F. Obermeier ◽  
R.L. Gelinas
Keyword(s):  
South Carolina ◽  
Preliminary Report ◽  
Field Studies

Influence of Shading by Soybeans (Glycine max) on Weed Suppression

Weed Science ◽  
1981 ◽  
Vol 29 (5) ◽  
pp. 610-615 ◽  
Author(s):  
T. R. Murphy ◽  
B. J. Gossett
Keyword(s):  
South Carolina ◽  
Glycine Max ◽  
Weed Control ◽  
Field Studies ◽  
Weed Suppression ◽  
Planting Dates ◽  
Early Season ◽  
Soybean Yield ◽  
Annual Weeds

Field studies were conducted at Florence and Clemson, South Carolina to measure the influence of soybean [Glycine max(L.) Merr.] planting dates on the length of early-season weed control needed to prevent yield reductions, the rate of shade development, and suppression of annual weeds by soybeans. The rate of shade development was similar for both planting dates during the 9- to 11-week period after planting for Florence and Clemson, respectively. The period of weed-free maintenance required to prevent soybean yield reductions was not affected by planting dates. With cultivation between rows, early- and late-planted soybeans required 3 weeks of weed-free maintenance to achieve maximum yields. Lower weed weights resulted from late than early soybean plantings. At Clemson, 3 weeks of weed-free maintenance for early and late plantings reduced weed weights 97 and 91%, respectively. Weed weights at Florence were reduced 85% with 3 weeks of weed-free maintenance for the late plantings, whereas 5 weeks were required to reduce weed weights 88% for early plantings.

Addition of Nonionic Surfactant to Glyphosate Plus Chlorimuron

2004 ◽  
Vol 18 (3) ◽  
pp. 588-593 ◽  
Author(s):  
Jason K. Norsworthy ◽  
Timothy L. Grey
Keyword(s):  
South Carolina ◽  
Nonionic Surfactant ◽  
Weed Control ◽  
Field Studies ◽  
Early Season ◽  
Glyphosate Formulation

Field studies were conducted in South Carolina and Georgia to evaluate weed control and soybean tolerance and yield after nonionic surfactant addition to combinations of chlorimuron plus an adjuvant-containing glyphosate formulation. Treatments included glyphosate alone, at 420 or 840 g ae/ha, or in combination with 6 or 9 g ai/ha chlorimuron and all possible combinations with or without 0.25% (v/v) nonionic surfactant. Other treatments included a weed-free and nontreated check. Chlorimuron plus glyphosate improved entireleaf, smallflower, and tall morningglory control over glyphosate alone, but nonionic surfactant addition did not further improve the control of any species, except tall morningglory. Up to 31% early-season injury was observed with the three-way mixture. Soybean injury was greater, and yields were reduced in one of three trials when nonionic surfactant was added to chlorimuron plus glyphosate combinations. This research indicates that there would be no benefit from the nonionic surfactant addition to this adjuvant-containing glyphosate formulation when combined with chlorimuron.

Differential Control of Palmer Amaranth (Amaranthus palmeri) and Smooth Pigweed (Amaranthus hybridus) by Postemergence Herbicides in Soybean (Glycine max)

1999 ◽  
Vol 13 (1) ◽  
pp. 165-168 ◽  
Author(s):  
Billy J. Gossett ◽  
Joe E. Toler
Keyword(s):  
South Carolina ◽  
Soybean Seed ◽  
Field Studies ◽  
Palmer Amaranth ◽  
High Rate ◽  
Herbicide Treatments ◽  
Differential Control ◽  
Seed Yields ◽  
Postemergence Herbicides ◽  
Smooth Pigweed

Field studies were conducted in South Carolina to evaluate the herbicides acifluorfen, chlorimuron, and imazaquin for control of Palmer amaranth and smooth pigweed in soybean, when applied 3 wk after weed emergence. Palmer amaranth was more difficult to control than smooth pigweed. Compared to untreated controls, acifluorfen, chlorimuron, and imazaquin reduced Palmer amaranth and smooth pigweed biomass 78 and 96%, 80 and 98%, and 82 and 99% at 30 d after treatment (DAT), 60 DAT, and at soybean harvest, respectively. The high rate (140 g/ha) of imazaquin provided greater control of Palmer amaranth than other herbicide treatments at soybean harvest. Except for the 140 g/ha rate of imazaquin, inadequate control of Palmer amaranth resulted in lower soybean seed yields for all herbicide treatments than the weed-free control. However, all herbicides controlled smooth pigweed to provide soybean seed yields similar to the weed-free control.

scholarly journals Measurements of reactive trace gases and variable O<sub>3</sub> formation rates in some South Carolina biomass burning plumes

2013 ◽  
Vol 13 (3) ◽  
pp. 1141-1165 ◽  
Author(s):  
S. K. Akagi ◽  
R. J. Yokelson ◽  
I. R. Burling ◽  
S. Meinardi ◽  
I. Simpson ◽  
...  
Keyword(s):  
South Carolina ◽  
Biomass Burning ◽  
Stand Structure ◽  
Trace Gases ◽  
Field Studies ◽  
Emission Factors ◽  
Trace Gas ◽  
Methanol Production ◽  
Fire Emissions ◽  
Reactive Trace Gases

Abstract. In October–November 2011 we measured trace gas emission factors from seven prescribed fires in South Carolina (SC), US, using two Fourier transform infrared spectrometer (FTIR) systems and whole air sampling (WAS) into canisters followed by gas-chromatographic analysis. A total of 97 trace gas species were quantified from both airborne and ground-based sampling platforms, making this one of the most detailed field studies of fire emissions to date. The measurements include the first emission factors for a suite of monoterpenes produced by heating vegetative fuels during field fires. The first quantitative FTIR observations of limonene in smoke are reported along with an expanded suite of monoterpenes measured by WAS including α-pinene, β-pinene, limonene, camphene, 4-carene, and myrcene. The known chemistry of the monoterpenes and their measured abundance of 0.4–27.9% of non-methane organic compounds (NMOCs) and ~ 21% of organic aerosol (mass basis) suggests that they impacted secondary formation of ozone (O3), aerosols, and small organic trace gases such as methanol and formaldehyde in the sampled plumes in the first few hours after emission. The variability in the initial terpene emissions in the SC fire plumes was high and, in general, the speciation of the initially emitted gas-phase NMOCs was 13–195% different from that observed in a similar study in nominally similar pine forests in North Carolina ~ 20 months earlier. It is likely that differences in stand structure and environmental conditions contributed to the high variability observed within and between these studies. Similar factors may explain much of the variability in initial emissions in the literature. The ΔHCN/ΔCO emission ratio, however, was found to be fairly consistent with previous airborne fire measurements in other coniferous-dominated ecosystems, with the mean for these studies being 0.90 ± 0.06%, further confirming the value of HCN as a biomass burning tracer. The SC results also support an earlier finding that C3-C4 alkynes may be of use as biomass burning indicators on the time-scale of hours to a day. It was possible to measure the downwind chemical evolution of the plume on four of the fires and significant O3 formation (ΔO3/ΔCO from 10–90%) occurred in all of these plumes within two hours. The slowest O3 production was observed on a cloudy day with low co-emission of NOx. The fastest O3 production was observed on a sunny day when the downwind plume almost certainly incorporated significant additional NOx by passing over the Columbia, SC metropolitan area. Due to rapid plume dilution, it was only possible to acquire high-quality downwind data for two other trace gas species (formaldehyde and methanol) during two of the fires. In all four of these cases, significant increases in formaldehyde and methanol were observed in <2 h. This is likely the first direct observation of post-emission methanol production in biomass burning plumes. Post-emission production of methanol does not always happen in young biomass burning plumes, and its occurrence in this study could have involved terpene precursors to a significant extent.

scholarly journals Measurements of reactive trace gases and variable O<sub>3</sub> formation rates in some South Carolina biomass burning plumes

2012 ◽  
Vol 12 (9) ◽  
pp. 25255-25328 ◽  
Author(s):  
S. K. Akagi ◽  
R. J. Yokelson ◽  
I. R. Burling ◽  
S. Meinardi ◽  
I. Simpson ◽  
...  
Keyword(s):  
South Carolina ◽  
Biomass Burning ◽  
Stand Structure ◽  
Trace Gases ◽  
Field Studies ◽  
Emission Factors ◽  
Trace Gas ◽  
Methanol Production ◽  
Fire Emissions ◽  
Reactive Trace Gases

Abstract. In October–November 2011 we measured trace gas emission factors from seven prescribed fires in South Carolina (SC), US, using two Fourier transform infrared spectrometer (FTIR) systems and whole air sampling (WAS) into canisters followed by gas-chromatographic analysis. A total of 97 trace gas species were quantified from both airborne and ground-based sampling platforms, making this one of the most detailed field studies of fire emissions to date. The measurements include the first emission factors for a suite of monoterpenes produced by heating vegetative fuels during field fires. The first quantitative FTIR observations of limonene in smoke are reported along with an expanded suite of monoterpenes measured by WAS including α-pinene, β-pinene, limonene, camphene, 4-carene, and myrcene. The known chemistry of the monoterpenes and their measured abundance of 0.4–27.9% of non-methane organic compounds (NMOCs) and ~21% of organic aerosol (mass basis) suggests that they impacted secondary formation of ozone (O3), aerosols, and small organic trace gases such as methanol and formaldehyde in the sampled plumes in first few hours after emission. The variability in the initial terpene emissions in the SC fire plumes was high and, in general, the speciation of the initially emitted gas-phase NMOCs was 13–195% different from that observed in a similar study in nominally similar pine forests in North Carolina ~20 months earlier. It is likely that differences in stand structure and environmental conditions contributed to the high variability observed within and between these studies. Similar factors may explain much of the variability in initial emissions in the literature. The ΔHCN/ΔCO emission ratio, however, was found to be fairly consistent with previous airborne fire measurements in other coniferous-dominated ecosystems, with the mean for these studies being 0.90 ± 0.06%, further confirming the value of HCN as a biomass burning tracer. The SC results also support an earlier finding that C3-C4 alkynes may be of use as biomass burning indicators on the time-scale of hours to a day. It was possible to measure the downwind chemical evolution of the plume on four of the fires and significant O3 formation (ΔO3/ΔCO from 10–90%) occurred in all of these plumes within two hours. The slowest O3 production was observed on a cloudy day with low co-emission of NOx. The fastest O3 production was observed on a sunny day when the downwind plume almost certainly incorporated significant additional NOx by passing over the Columbia, SC metropolitan area. Due to rapid plume dilution, it was only possible to acquire high-quality downwind data for two other trace gas species (formaldehyde and methanol) during two of the fires. In all four of these cases, significant increases in formaldehyde and methanol were observed in <2 h. This is likely the first direct observation of post-emission methanol production in biomass burning plumes. Post-emission production of methanol does not always happen in young biomass burning plumes, and its occurrence in this study could have involved terpene precursors to a significant extent.

Characteristics of Seismically Induced Liquefaction Sites and Features Located in the Vicinity of the 1886 Charleston, South Carolina Earthquake

1990 ◽  
Vol 61 (2) ◽  
pp. 117-130 ◽  
Author(s):  
David Amick ◽  
Garry Maurath ◽  
Robert Gelinas
Keyword(s):  
South Carolina ◽  
Coastal Plain ◽  
Regional Analysis ◽  
Field Studies ◽  
Atlantic Coastal Plain ◽  
Epicentral Area ◽  
Atlantic Seaboard ◽  
Historic Record ◽  
Historical Accounts ◽  
Atlantic Coastal

Abstract The ages of seismically induced paleoliquefaction features located in the Charleston, S. C. area suggest that the return period between large events similar to the 1886 earthquake is much longer than the historic record. If large prehistoric earthquakes have occurred elsewhere along the Atlantic Seaboard, then evidence of liquefaction features associated with them should be present in unconsolidated Pleistocene and Holocene deposits. To establish a comprehensive control data base for a regional analysis, liquefaction sites and features located in the Charleston area have been evaluated. Over 100 liquefaction sites were identified on the basis of a detailed review of historical accounts of the 1886 earthquake, and results of recent field studies. These studies then centered on characterizing the geologic, stratigraphic, and hydrologic setting of these sites and identifying criteria by which similar locales could be recognized elsewhere in the Atlantic Coastal Plain. This investigation also included the development of recognition criteria to distinguish seismically induced liquefaction features from pseudoliquefaction features (other features which look similar but are not seismic in origin). Guided by these findings, a systematic search for paleoliquefaction features outside the epicentral area of the 1886 Charleston earthquake is now underway.

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