Characterization of Drought in the South Atlantic, United States

2013 ◽  
Vol 49 (6) ◽  
pp. 1385-1397 ◽  
Author(s):  
Lauren A. Patterson ◽  
Brian D. Lutz ◽  
Martin W. Doyle
Keyword(s):  
United States ◽  
South Atlantic ◽  
The South

scholarly journals Regional Characterization of Tornado Activity

2013 ◽  
Vol 52 (3) ◽  
pp. 654-659 ◽  
Author(s):  
Robert J. Trapp ◽  
Harold E. Brooks
Keyword(s):  
United States ◽  
High Activity ◽  
Gamma Distribution ◽  
The United States ◽  
South Atlantic ◽  
Major Contributor ◽  
The South ◽  
Upper Midwest ◽  
Statistical Behavior

AbstractIn the United States, tornado activity of a given year is usually assessed in terms of the total number of human-reported tornadoes. Such assessments fail to account for the seldom-acknowledged fact that an active (or inactive) tornado year for the United States does not necessarily equate with activity (or inactivity) everywhere in the country. The authors illustrate this by comparing the geospatial tornado distributions from 1987, 2004, and 2011. Quantified in terms of the frequency of daily tornado occurrence (or “tornado days”), the high activity in the South Atlantic and upper Midwest regions was a major contributor to the record-setting number of tornadoes in 2004. The high activity in 2011 arose from significant tornado occurrences in the Southeast and lower Midwest. The authors also show that the uniqueness of the activity during these years can be determined by modeling the local statistical behavior of tornado days by a gamma distribution.

Anorogenic magmatism and the Grenvillian Orogeny

1989 ◽  
Vol 26 (3) ◽  
pp. 479-489 ◽  
Author(s):  
Brian F. Windley
Keyword(s):  
United States ◽  
South America ◽  
Continental Margin ◽  
South Atlantic ◽  
Island Arc ◽  
The South ◽  
The West ◽  
Continental Block ◽  
Grenvillian Orogeny ◽  
Alkaline Complexes

The Grenvillian Orogeny was preceded by extensive anorogenic volcanism and plutonism in the period 1500–1300 Ma in the form of rhyolites, epizonal granites, anorthosites, gabbros, alkaline complexes, and basic dykes. An analogue for the mid-Proterozoic anorogenic complexes is provided by the 2000 km by 200 km belt of anorogenic complexes in the Hoggar, Niger, and Nigeria, which contain anorthosites, gabbros, and peralkaline granites and were generated in a Cambrian to Jurassic rift that farther south led to the formation of the South Atlantic. An analogue for the 1 × 106 km2 area of 1500–1350 Ma rhyolites (and associated epizonal granites) that underlie the mid-continental United States is provided by the 1.7 × 106 km2 area of Jurassic Tobifera rhyolites in Argentina, which were extruded on the stretched continental margin of South America immediately preceding the opening of the South Atlantic. The mid-Proterozoic complexes were intruded close to the continental margin of the Grenvillian ocean and were commonly superimposed by the craton-directed thrusts that characterized the final stages of the Grenvillian Orogeny. The bulk of the Keweenawan rift and associated anorogenic magmatism formed about 1100 Ma at the same time as the Ottawan Orogeny in Ontario, which probably resulted from the collision of the island arc of the Central Metasedimentary Belt attached to the continental block in the east with the continental block to the west. The most appropriate modern equivalent would be the Rhine Graben, which formed at the same time as the main Alpine compression.

Deep-water Raphitomidae (Mollusca, Gastropoda, Conoidea) from the Campos Basin, southeast Brazil

Zootaxa ◽  
2012 ◽  
Vol 3527 (1) ◽  
pp. 1
Author(s):  
RAQUEL MEDEIROS ANDRADE FIGUEIRA ◽  
RICARDO SILVA ABSALÃO
Keyword(s):  
Continental Slope ◽  
Deep Water ◽  
South Atlantic ◽  
The South ◽  
Southeast Brazil ◽  
Campos Basin ◽  
Soft Bottoms ◽  
First Time ◽  
Box Corer

During the program “Environmental Characterization of the Campos Basin, RJ, Brazil”, carried out from 2001 to 2003,117 stations were sampled on the continental slope of the Campos Basin off southeast Brazil, by the Research Vessel“Astro-Garoupa”. The samples were taken on soft bottoms at depths from 700 to 1950 m, with a 0.25 m2 box corer or bydredging with a Charcot dredge. Mollusks were present at all of the stations, and among the Gastropoda the Conoideashowed the highest diversity. Here we present the results obtained for the most abundant family, Raphitomidae. We found21 species in eight genera: Famelica, Eubela, Xanthodaphne, Magnella, Gymnobela, Pleurotomella, Aliceia andNeopleurotomoides. The last two genera are reported here for the first time in the South Atlantic Ocean. Among the 21species two had been previously reported for this region: Magnella malmii (Dall, 1889) and M. extensa (Dall, 1881).Three species had been reported for Brazil, but the new finds expand their known geographical distribution: Eubelalimacina (Dall, 1881), Famelica mirmidina (Dautzenberg & Fischer, 1986) and Pleurotomella cala (Watson, 1885).Twelve species are reported for the first time in the South Atlantic: Aliceia aenigmatica Dautzenberg & Fischer, 1897,Xanthodaphne dalmasi (Dautzenberg & Fischer, 1897), Xanthodaphne araneosa (Watson, 1881), Magnella watsoni(Dautzenberg, 1889), Gymnobela chyta (Watson, 1881), G. atypha (Bush, 1893), Gymnobela bairdii (Verrill & Smith,1884), Gymnobela blakeana Dall, 1881, Pleurotomella perpauxilla (Watson, 1881), P. bureaui (Dautzenberg & Fischer,1897), P. cf. anceyi (Dautzenberg & Fischer, 1897) and P. coelorhaphe (Dautzenberg & Fischer, 1896). Four species arenew to science and are described here: Neopleurotomoides aembe, Xanthodaphne pichi, Gymnobela xaioca and Pleurotomella ybessa.

Sign in / Sign up

Export Citation Format

Share Document