scholarly journals Methodological proposal for characterization of marine geodiversity in the South Atlantic: Vitória-Trindade Ridge and adjacent areas, southeast of Brazil

2015 ◽  
Vol 15 (3) ◽  
pp. 293-309 ◽  
Author(s):  
Maria Adelaide Mansini Maia ◽  
João Wagner de Alencar Castro
Keyword(s):  
South Atlantic ◽  
The South

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.

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.

scholarly journals Non-monotonic growth and motion of the South Atlantic Anomaly

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Hagay Amit ◽  
Filipe Terra-Nova ◽  
Maxime Lézin ◽  
Ricardo I. Trindade
Keyword(s):  
Large Scale ◽  
South Atlantic ◽  
The South ◽  
South Atlantic Anomaly ◽  
Societal Issues ◽  
Special Events ◽  
Core Dynamics ◽  
Intensity Changes ◽  
The Magnetic Field

AbstractThe South Atlantic Anomaly (SAA) is a region at Earth’s surface where the intensity of the magnetic field is particularly low. Accurate characterization of the SAA is important for both fundamental understanding of core dynamics and the geodynamo as well as societal issues such as the erosion of instruments at surface observatories and onboard spacecrafts. Here, we propose new measures to better characterize the SAA area and center, accounting for surface intensity changes outside the SAA region and shape anisotropy. Applying our characterization to a geomagnetic field model covering the historical era, we find that the SAA area and center are more time dependent, including episodes of steady area, eastward drift and rapid southward drift. We interpret these special events in terms of the secular variation of relevant large-scale geomagnetic flux patches on the core–mantle boundary. Our characterization may be used as a constraint on Earth-like numerical dynamo models.

scholarly journals Drilling the Aptian–Albian of the Sergipe–Alagoas Basin, Brazil: paleobiogeographic and paleoceanographic studies in the South Atlantic

2021 ◽  
Vol 29 ◽  
pp. 1-17
Author(s):  
Gerson Fauth ◽  
Mauro Daniel Rodrigues Bruno ◽  
Jorge Villegas-Martín ◽  
Jairo Francisco Savian ◽  
Rodrigo do Monte Guerra ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
South Atlantic ◽  
South Atlantic Ocean ◽  
The South ◽  
Future Studies ◽  
Tethys Sea ◽  
Fine Grained ◽  
Lithostratigraphic Units ◽  
Coarse To Fine

Abstract. The Aptian–Albian interval is characterized by significant paleoclimatic, paleoceanographic, and paleogeographic changes, which in turn affected the distribution and evolution of marine ecosystems. Despite the importance of such studies, there have been few correlations between Aptian–Albian sections of the Tethys Sea and those of the South Atlantic Ocean. This interval, including the Aptian–Albian transition, is preserved in the deposits of the Riachuelo Formation (Sergipe–Alagoas Basin, Brazil) located in the South Atlantic Ocean; therefore, this location was chosen for drilling four new cores. The goals of this paper are as follows: (1) to explain the drilling operation carried out in the deposits of the Riachuelo Formation and the methods used; (2) to present a brief lithostratigraphic characterization of the holes and the paleomagnetic data of core SER-03; and (3) to describe the high potential of the cores recovered for additional investigation in the future. The lithostratigraphic units of the SER-01 core consist mainly of coarse- to fine-grained sandstone, shales, marls, and mudstones; the SER-02 core was excluded due to low recovery; the SER-03 core is mainly composed of fine-grained sediments (shale, marls, and packstone) and bears some ammonite shells; the lithology of core SER-04 is mainly sandstones. Magnetic susceptibility values (χlf and χhf) and frequency-dependent susceptibility (χfd) data suggest that the section is located within the Cretaceous Normal Superchron. Future studies on these cores integrating micropaleontological, paleoichnological, geochemical, stratigraphic, and paleomagnetic (e.g., relative intensity) data will allow for a better understanding of paleoceanographic and paleogeographic events related to the early evolution of the South Atlantic Ocean and how these events correlate to similar events in Tethyan sections.

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
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