scholarly journals A coastal upwelling seesaw in the Atlantic Ocean as a result of the closure of the Central American Seaway

2004 ◽  
Vol 31 (17) ◽  
pp. n/a-n/a ◽  
Author(s):  
M. Prange ◽  
M. Schulz
Keyword(s):  
Atlantic Ocean ◽  
Coastal Upwelling ◽  
Central American ◽  
Central American Seaway

FLOW REVERSAL IN THE CENTRAL AMERICAN SEAWAY DURING OR AFTER THE OLIGOCENE MIOCENE TRANSITION

2017 ◽  
Author(s):  
Andrew Jeffrey Fraass ◽  
◽  
R. Mark Leckie ◽  
Christopher M. Lowery ◽  
Robert DeConto
Keyword(s):  
Flow Reversal ◽  
Central American ◽  
Central American Seaway

scholarly journals Sinking rates and ballast composition of particles in the Atlantic Ocean: implications for the organic carbon fluxes to the deep ocean

2009 ◽  
Vol 6 (1) ◽  
pp. 85-102 ◽  
Author(s):  
G. Fischer ◽  
G. Karakaş
Keyword(s):  
Organic Carbon ◽  
Atlantic Ocean ◽  
Sediment Trap ◽  
Carbon Flux ◽  
Coastal Upwelling ◽  
Production Systems ◽  
Deep Ocean ◽  
Biogeochemical Model ◽  
Carbonate Content ◽  
Organic Carbon Flux

Abstract. The flux of materials to the deep sea is dominated by larger, organic-rich particles with sinking rates varying between a few meters and several hundred meters per day. Mineral ballast may regulate the transfer of organic matter and other components by determining the sinking rates, e.g. via particle density. We calculated particle sinking rates from mass flux patterns and alkenone measurements applying the results of sediment trap experiments from the Atlantic Ocean. We have indication for higher particle sinking rates in carbonate-dominated production systems when considering both regional and seasonal data. During a summer coccolithophorid bloom in the Cape Blanc coastal upwelling off Mauritania, particle sinking rates reached almost 570 m per day, most probably due the fast sedimentation of densely packed zooplankton fecal pellets, which transport high amounts of organic carbon associated with coccoliths to the deep ocean despite rather low production. During the recurring winter-spring blooms off NW Africa and in opal-rich production systems of the Southern Ocean, sinking rates of larger particles, most probably diatom aggregates, showed a tendency to lower values. However, there is no straightforward relationship between carbonate content and particle sinking rates. This could be due to the unknown composition of carbonate and/or the influence of particle size and shape on sinking rates. It also remains noticeable that the highest sinking rates occurred in dust-rich ocean regions off NW Africa, but this issue deserves further detailed field and laboratory investigations. We obtained increasing sinking rates with depth. By using a seven-compartment biogeochemical model, it was shown that the deep ocean organic carbon flux at a mesotrophic sediment trap site off Cape Blanc can be captured fairly well using seasonal variable particle sinking rates. Our model provides a total organic carbon flux of 0.29 Tg per year down to 3000 m off the NW African upwelling region between 5 and 35° N. Simple parameterisations of remineralisation and sinking rates in such models, however, limit their capability in reproducing the flux variation in the water column.

scholarly journals Influence of the Central American Seaway and Drake Passage on ocean circulation and neodymium isotopes: A model study

2014 ◽  
Vol 29 (12) ◽  
pp. 1214-1237 ◽  
Author(s):  
Patrik L. Pfister ◽  
Thomas F. Stocker ◽  
Johannes Rempfer ◽  
Stefan P. Ritz
Keyword(s):  
Ocean Circulation ◽  
Drake Passage ◽  
Central American ◽  
Neodymium Isotopes ◽  
Model Study ◽  
Central American Seaway

scholarly journals Investigation of the abundance, distribution and composition of microplastics at coastal upwelling sites in the Atlantic Ocean

2016 ◽  
Author(s):  
La Daana K Kanhai ◽  
Rick Officer ◽  
Ian O'Connor ◽  
Richard C Thompson
Keyword(s):  
Atlantic Ocean ◽  
Surface Waters ◽  
Primary Productivity ◽  
Null Hypothesis ◽  
Latitudinal Gradient ◽  
Coastal Upwelling ◽  
Abundance Distribution ◽  
Significant Difference ◽  
Benguela Upwelling ◽  
Canary Upwelling

Microplastics are an issue of international concern due to the fact that these substances may potentially threaten biota by (i) causing physical harm, (ii) transporting persistent, bioaccumulating and toxic (PBT) substances and, (iii) leaching plastic additives. Within the world’s oceans, areas which experience coastal upwelling are biota rich due to their high levels of primary productivity. The assessment of microplastic presence in areas which experience coastal upwelling is vital as it will indicate whether microplastics are an issue of concern in areas which support key biological resources. The null hypothesis of the present study is that microplastic abundance will be lower in areas where there is upwelling. As such, the present study aims to investigate whether microplastic abundance in upwelled areas in the Atlantic Ocean is significantly different from non-upwelled areas. Based on an opportunistic voyage aboard the RV Polarstern, microplastics will be sampled in sub-surface waters along a diverse latitudinal gradient in the Atlantic Ocean i.e. from Bremerhaven (Germany) to Cape Town (South Africa). Based on the proposed route, it will be possible to determine microplastic levels at two areas of coastal upwelling in the Atlantic Ocean (i) Canary Upwelling Ecosystem (CUE) and (ii) Benguela Upwelling Ecosystem (BUE). The results will then be analysed to determine whether there was a statistically significant difference between ‘upwelled areas’ and ‘non-upwelled areas’.

Middle Miocene closure of the Central American Seaway

Science ◽  
2015 ◽  
Vol 348 (6231) ◽  
pp. 226-229 ◽  
Author(s):  
C. Montes ◽  
A. Cardona ◽  
C. Jaramillo ◽  
A. Pardo ◽  
J. C. Silva ◽  
...  
Keyword(s):  
Middle Miocene ◽  
Central American ◽  
Central American Seaway

scholarly journals Protoconch enlargement in Western Atlantic turritelline gastropod species following the closure of the Central American Seaway

2019 ◽  
Vol 9 (9) ◽  
pp. 5309-5323 ◽  
Author(s):  
Stephanie Sang ◽  
Dana Suzanne Friend ◽  
Warren Douglas Allmon ◽  
Brendan Matthew Anderson
Keyword(s):  
Central American ◽  
Gastropod Species ◽  
Western Atlantic ◽  
Central American Seaway

Biogeography of Iberian Atlantic Neogene marginelliform gastropods (Marginellidae, Cystiscidae): global change and transatlantic colonization

2011 ◽  
Vol 85 (6) ◽  
pp. 1052-1066 ◽  
Author(s):  
Carlos Marques Da Silva ◽  
Bernard Landau ◽  
Rafael La Perna
Keyword(s):  
West Africa ◽  
Sea Water ◽  
Atlantic Coast ◽  
Central American ◽  
Marine Gastropods ◽  
High Productivity ◽  
Complex Process ◽  
Central American Seaway ◽  
Central Portugal ◽  
The Caribbean

The Marginellidae Fleming and the Cystiscidae Stimpson, herein collectively referred to as marginelliform gastropods, are convergent families of thermophilic marine gastropods. Shallow-water marginelliform gastropods are found in the Ibero-Moroccan Gulf and Mediterranean, diversity rapidly increasing towards tropical West Africa. Surprisingly, in the tropical and subtropical European Miocene fossil record, marginelliform genera of tropical affinity such asPersiculaSchumacher andPrunumHerrmannsen, occurring today in West Africa, are altogether missing. Others, such asMarginellaLamarck, are present only in the southwestern Iberian and Mediterranean Neogene record. This work describes the marginelliform gastropods from the Atlantic Iberian Neogene. Ten species are recorded, of which three are new,Persicula mikhailovaen. sp.,Gibberula costaen. sp., andGibberula brebionin. sp. This study shows thatGibberulaSwainson andVolvarinaHinds have been present in Europe since the Eocene.Marginellamay have originated in southern Africa and migrated north to Europe in the Miocene, never extending further north than west central Portugal.PersiculaandPrunumprobably originated in the Caribbean and migrated east during the Pliocene, following closure of the Central American Seaway. The colonization of the Pliocene European Atlantic coast by gastropods of these genera was selective, only where high sea-water temperature and high productivity were combined. These findings suggest that post-Messinian recolonization of the Mediterranean during the Pliocene was a complex process, involving colonization by groups originating in various regions of the Atlantic, including Europe, Africa and the Americas.

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