Spatiotemporal Variability in ΔR in the Northern Gulf of Mexico, USA

Radiocarbon ◽  
2016 ◽  
Vol 59 (2) ◽  
pp. 343-353 ◽  
Author(s):  
Carla S Hadden ◽  
Alexander Cherkinsky
Keyword(s):  
Gulf Of Mexico ◽  
Gulf Coast ◽  
Spatiotemporal Variability ◽  
Major Influence ◽  
Data Set ◽  
Spatial And Temporal Scales ◽  
Northern Gulf Of Mexico ◽  
Northern Gulf Coast ◽  
Gulf Coast Region ◽  
Coast Region

AbstractStrombus alatus and Busycon sinistrum are large marine gastropods that are frequently recovered from archaeological contexts in southeastern North America. We previously proposed a reservoir age offset (ΔR) for B. sinistrum from the northern Gulf of Mexico region based on known-age pre-bomb 20th-century specimens. We also reported significant variability in radiocarbon both among and within S. alatus specimens, which precluded a reliable estimation of ΔR for this taxon. In this paper, we present a complementary data set from archaeological contexts to re-evaluate marine reservoir effects in the northern Gulf Coast region at multiple spatial and temporal scales. The new data set consists of a total of 13 14C age determinations from well-associated marine (B. sinistrum and S. alatus) and terrestrial (Odocoileus virginianus) samples from a closed context at the Bayou St. John (1BA21) archaeological site. We suggest a slightly updated ∆R value of –2±53 14C yr for late Holocene-age B. sinistrum from the northern Gulf Coast region. S. alatus, and possibly other species of strombid conchs, are poor candidates for 14C dating due to the highly variable 14C content observed within and among specimens. Though subregional variability in inputs of 14C-depleted waters is likely, life-history factors related to ontogenetic niche and/or habitat shifts appear to be a major influence in shell 14C for S. alatus.

scholarly journals The Roles of Labor and Profitability in Choosing a Grazing Strategy for Beef Production in the U.S. Gulf Coast Region

2008 ◽  
Vol 40 (1) ◽  
pp. 301-313 ◽  
Author(s):  
Jeffrey M. Gillespie ◽  
Wayne Wyatt ◽  
Brad Venuto ◽  
David Blouin ◽  
Robert Boucher
Keyword(s):  
Gulf Coast ◽  
Stocking Rate ◽  
Rotational Grazing ◽  
Data Set ◽  
Time And Motion ◽  
Continuous Grazing ◽  
Labor Requirements ◽  
Gulf Coast Region ◽  
Coast Region ◽  
The U.S

Comparisons are made concerning labor required and profitability associated with continuous grazing at three stocking rates and rotational grazing at a high stocking rate in the U.S. Gulf Coast region. A unique data set was collected using a time and motion study method to determine labor requirements. Profits are lowest for low stocking rate–continuous grazing and high stocking rate–rotational grazing. Total labor and labor in three specific categories are greater on per acre and/or per cow bases with rotational-grazing than with continuous-grazing strategies. These results help to explain relatively low adoption rates of rotational grazing in the region.

scholarly journals The Roles of Labor and Profitability in Choosing a Grazing Strategy for Beef Production in the U.S. Gulf Coast Region

2008 ◽  
Vol 40 (01) ◽  
pp. 301-313 ◽  
Author(s):  
Jeffrey M. Gillespie ◽  
Wayne Wyatt ◽  
Brad Venuto ◽  
David Blouin ◽  
Robert Boucher
Keyword(s):  
Gulf Coast ◽  
Stocking Rate ◽  
Rotational Grazing ◽  
Data Set ◽  
Time And Motion ◽  
Continuous Grazing ◽  
Labor Requirements ◽  
Gulf Coast Region ◽  
Coast Region ◽  
The U.S

Comparisons are made concerning labor required and profitability associated with continuous grazing at three stocking rates and rotational grazing at a high stocking rate in the U.S. Gulf Coast region. A unique data set was collected using a time and motion study method to determine labor requirements. Profits are lowest for low stocking rate–continuous grazing and high stocking rate–rotational grazing. Total labor and labor in three specific categories are greater on per acre and/or per cow bases with rotational-grazing than with continuous-grazing strategies. These results help to explain relatively low adoption rates of rotational grazing in the region.

Warm Season Lightning Distributions over the Northern Gulf of Mexico Coast and Their Relation to Synoptic-Scale and Mesoscale Environments

2005 ◽  
Vol 20 (4) ◽  
pp. 415-438 ◽  
Author(s):  
Jessica R. Smith ◽  
Henry E. Fuelberg ◽  
Andrew I. Watson
Keyword(s):  
Gulf Of Mexico ◽  
Large Scale ◽  
Gulf Coast ◽  
Warm Season ◽  
Sea Breeze ◽  
Northern Gulf Of Mexico ◽  
Low Level ◽  
Lake Charles ◽  
Northern Gulf Coast ◽  
Mexico Coast

Abstract Cloud-to-ground lightning data from the National Lightning Detection Network are used to create a warm season (May–September) lightning climatology for the northern Gulf of Mexico coast for the 14-yr period 1989–2002. Each day is placed into one of five flow regimes based on the orientation of the low-level flow with respect to the coastline. This determination is made using the vector mean 1000–700-hPa wind data at Lake Charles and Slidell, Louisiana. Flash densities are calculated for daily, hourly, and nocturnal periods. Spatial patterns of composite 24-h and nocturnal flash density indicate that lightning decreases in an east-to-west direction over the region. Flash densities for the 24-h period are greatest over land near the coast, with relative maxima located near Houston, Texas; Lake Charles, Baton Rouge, and New Orleans, Louisiana; Biloxi, Mississippi; and Mobile, Alabama. Flash densities during the nocturnal period are greatest over the coastal waters. Lightning across the northern Gulf coast is closely related to the prevailing low-level synoptic flow, which controls the sea breeze, the dominant forcing mechanism during the warm season. Southwest flow, the most unstable and humid of the five regimes, exhibits the most flashes. In this case, sea-breeze-induced convection is located slightly inland from the coast. Northeast flow, the driest and most stable of the regimes, exhibits the least amount of lightning. The large-scale flow restricts the sea breeze to near the coastline. Geographic features and local mesoscale circulations are found to affect lightning across the region. Geographic features include lakes, bays, marshes, swamps, and coastline orientations. Thermal circulations associated with these features interact with the main sea breeze to produce complex lightning patterns over the area.

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