scholarly journals Demosponges from the Northern Mid-Atlantic Ridge shed more light on the diversity and biogeography of North Atlantic deep-sea sponges

2015 ◽  
Vol 95 (7) ◽  
pp. 1475-1516 ◽  
Author(s):  
Paco Cárdenas ◽  
Hans Tore Rapp
Keyword(s):  
North Atlantic ◽  
Fracture Zone ◽  
Deep Sea ◽  
The North ◽  
Mid Atlantic Ridge ◽  
The North Atlantic

In July–August 2004, the Mid-Atlantic Ridge Ecosystems (MAR-Eco) expedition collected Demospongiae (Porifera) from the Northern Mid-Atlantic Ridge (MAR) north of the Azores, between 41°N and 61°N. Demosponges were found at 10 stations, at depths ranging from 753 to 3046 m. Twenty-two species were identified: 17 Tetractinellida, one Polymastiida, one Suberitida, two Poecilosclerida and one Dendroceratida. The study of this material is an opportunity to revise the taxonomy and the North Atlantic distribution of each of these deep-sea species. Some species are particularly rare and poorly known (Tetilla longipilis, Tetilla sandalina, Craniella azorica, Polymastia corticata) and two are new to science:Forcepia(Forcepia)toxaferasp. nov. andIotroata paravaridenssp. nov. This study suggests that the MAR is not a longitudinal barrier for the dispersal of deep-sea demosponges while on the contrary, the Charlie-Gibbs Fracture Zone (CGFZ) may be a latitudinal border for the dispersal of deep-sea demosponges, due to great depths and currents.

scholarly journals Interannual Variability in the Pathways of the North Atlantic Current over the Mid-Atlantic Ridge and the Impact of Topography

2008 ◽  
Vol 38 (1) ◽  
pp. 104-120 ◽  
Author(s):  
Amy S. Bower ◽  
Wilken-Jon von Appen
Keyword(s):  
Time Series ◽  
North Atlantic ◽  
Fracture Zone ◽  
Subpolar Gyre ◽  
North Atlantic Current ◽  
The North ◽  
Mid Atlantic Ridge ◽  
The North Atlantic ◽  
The Impact ◽  
Atlantic Current

Abstract Recent studies have indicated that the North Atlantic Ocean subpolar gyre circulation undergoes significant interannual-to-decadal changes in response to variability in atmospheric forcing. There are also observations, however, suggesting that the southern limb of the subpolar gyre, namely, the eastward-flowing North Atlantic Current (NAC), may be quasi-locked to particular latitudes in the central North Atlantic by fracture zones (gaps) in the Mid-Atlantic Ridge. This could constrain the current’s ability to respond to variability in forcing. In the present study, subsurface float trajectories at 100–1000 m collected during 1997–99 and satellite-derived surface geostrophic velocities from 1992 to 2006 are used to provide an improved description of the detailed pathways of the NAC over the ridge and their relationship to bathymetry. Both the float and satellite observations indicate that in 1997–99, the northern branch of the NAC was split into two branches as it crossed the ridge, one quasi-locked to the Charlie–Gibbs Fracture Zone (CGFZ; 52°–53°N) and the other to the Faraday Fracture Zone (50°–51°N). The longer satellite time series shows, however, that this pattern did not persist outside the float sampling period and that other branching modes persisted for one or more years, including an approximately 12-month time period in 2002–03 when the strongest eastward flow over the ridge was at ∼49°N. Schott et al. showed how northward excursions of the NAC can temporarily block the westward flow of the Iceland–Scotland Overflow Water through the CGFZ. From the 13-yr time series of surface geostrophic velocity, it is estimated that such blocking may occur on average 6% of the time, although estimates for any given 12-month period range from 0% to 35%.

Preliminary report on the North Atlantic deep-sea cores taken by the Geophysical Laboratory, Carnegie Institution

1937 ◽  
Vol 18 (1) ◽  
pp. 224
Author(s):  
W. H. Bradley ◽  
M. N. Bramlette ◽  
J. A. Cushman ◽  
L. G. Henbest ◽  
K. E. Lahman ◽  
...  
Keyword(s):  
North Atlantic ◽  
Deep Sea ◽  
Preliminary Report ◽  
Carnegie Institution ◽  
The North ◽  
The North Atlantic

scholarly journals Kinematic sequence stratigraphy of the European Cenozoic Rift System and Alpine Foreland Basin: correlation with Mediterranean and Atlantic plate-boundary events

2006 ◽  
Vol 85 (2) ◽  
pp. 77-129 ◽  
Author(s):  
W. Sissingh
Keyword(s):  
North Atlantic ◽  
Plate Boundary ◽  
Foreland Basin ◽  
Rift System ◽  
The North ◽  
Mid Atlantic Ridge ◽  
Alpine Foreland ◽  
Alpine Foreland Basin ◽  
The North Atlantic ◽  
Plate Kinematics

AbstractA review of the sequence stratigraphic development of the Tertiary basins of the North and West Alpine Foreland domains shows that their structural and depositional history was episodically affected by brief tectonic phases. These were associated with intermittent deformation events induced by the collisional convergence and compressional coupling of the Apulian and Iberian microplates with the European Plate. The plate kinematics-related episodicity was essentially isochronously recorded in the basin fills of the Alpine Foreland region. These are generally correlative with changes in eustatic sea level. The ensuing correlative successions of so-called Cenozoic Rift and Foredeep (CRF) sequences and phases can be traced throughout the European Cenozoic Rift System and Alpine Foreland Basin. Their temporal correlation indicates that, apparently, the changes in the plate collision-related stress regime of the Alpine Foreland were repeatedly accompanied by coeval changes in eustatic sea level. To test and substantiate the validity of this inferred causal relationship between intraplate deposition, plate kinematics and eustacy, the tectono-sedimentary evolution of the basins of the Mediterranean plate-boundary zone has been analysed in conjunction with a review of the plate-boundary events in the North Atlantic. Within the uncertainty range of available datings, synchroneity could thus be demonstrated for the punctuated tectonostratigraphic development of basins of the western Mediterranean (comprising the Liguro-Provençal Basin, Valencia Trough, Sardinia Rift and Tyrrhenian Basin), the Apenninic-Calabrian Arc, the Betic domain (including the Alboran Basin) and the North and West Alpine Foreland regions. Similar temporal correlations of plate tectonicsrelated events near the Mid-Atlantic Ridge in the North Atlantic and tectonostratigraphic sequences and phases of the Alpino-Pyrenean Foreland basins are further evidence of a common causal mechanism. The driving mechanisms appear to have been the northward drift of Africa and the resulting mechanical coupling of Apulia and Iberia with the southern passive margin of Europe, as well as the stepwise opening of the North Atlantic and accompanying episodic plate re-organisations of the Mid-Atlantic Ridge.

A barotolerant ciliate isolated from the abyssal deep sea of the North Atlantic: Euplotes dominicanus sp. n. (Ciliophora, Euplotia)

2020 ◽  
Vol 73 ◽  
pp. 125664 ◽  
Author(s):  
Suzana Živaljić ◽  
Anja Scherwass ◽  
Alexandra Schoenle ◽  
Manon Hohlfeld ◽  
Pablo Quintela-Alonso ◽  
...  
Keyword(s):  
North Atlantic ◽  
Deep Sea ◽  
The North ◽  
The North Atlantic

scholarly journals Influence of Water Masses on the Biodiversity and Biogeography of Deep-Sea Benthic Ecosystems in the North Atlantic

2020 ◽  
Vol 7 ◽  
Author(s):  
Patricia Puerta ◽  
Clare Johnson ◽  
Marina Carreiro-Silva ◽  
Lea-Anne Henry ◽  
Ellen Kenchington ◽  
...  
Keyword(s):  
North Atlantic ◽  
Deep Sea ◽  
Water Masses ◽  
The North ◽  
Influence Of Water ◽  
The North Atlantic ◽  
Benthic Ecosystems

New species, occurrence records and observations of predation by deep-sea Asteroidea (Echinodermata) from the North Atlantic by NOAA ship Okeanos Explorer

Zootaxa ◽  
2020 ◽  
Vol 4766 (2) ◽  
pp. 201-260 ◽  
Author(s):  
CHRISTOPHER L. MAH
Keyword(s):  
North Atlantic ◽  
Deep Sea ◽  
Substantial Contribution ◽  
The North ◽  
In Situ Observations ◽  
The North Atlantic ◽  
Feeding Observations ◽  
Occurrence Records ◽  
In Situ Feeding

Exploratory cruises by the NOAA Ship Okeanos Explorer have resulted in a substantial contribution in our understanding of deep-sea echinoderm biodiversity, biology, and ecology in the North Atlantic. This includes the description and in situ feeding observations of two, new corallivorous goniasterid species, Evoplosoma nizinskiae n. sp. and Sibogaster bathyheuretor n. sp. Significant in situ observations include a synchronous feeding event including multiple goniasterid asteroids and a cidaroid urchin on a large demosponge, providing new data for understanding echinoderm feeding behavior, including agonistic behavior, in deep-sea settings and new, in situ feeding observations for 28 deep-sea species including the myxasterid Pythonaster atlantidis, the korethrasterid Remaster palmatus and the poorly understood hippasterine goniasterids, Gilbertaster caribaea and Sthenaster emmae. 

scholarly journals Molecular circumscription of new species of Gyrocotyle Diesing, 1850 (Cestoda) from deep-sea chimaeriform holocephalans in the North Atlantic

2020 ◽  
Vol 97 (3) ◽  
pp. 285-296
Author(s):  
Rodney A. Bray ◽  
Andrea Waeschenbach ◽  
D. Timothy J. Littlewood ◽  
Odd Halvorsen ◽  
Peter D. Olson
Keyword(s):  
New Species ◽  
North Atlantic ◽  
Deep Sea ◽  
The North ◽  
The North Atlantic

scholarly journals A review of the genus Iridogorgia (Octocorallia: Chrysogorgiidae) and its relatives, chiefly from the North Atlantic Ocean

2007 ◽  
Vol 87 (2) ◽  
pp. 393-402 ◽  
Author(s):  
Les Watling
Keyword(s):  
New Species ◽  
Atlantic Ocean ◽  
New England ◽  
North Atlantic ◽  
Deep Sea ◽  
New Genus ◽  
Growth Form ◽  
North Atlantic Ocean ◽  
The North ◽  
The North Atlantic

Exploration of the New England and Corner Rise Seamounts produced four new species of chrysogorgiid octocorals with the spiral iridogorgiid growth form. Three species are described as new in the genus Iridogorgia and one is described in the new genus Rhodaniridogorgia. Both genera have representatives in the Atlantic and Pacific Oceans. Iridogorgia magnispiralis sp. nov., is one of the largest octocorals encountered in the deep sea and seems to be widespread in the Atlantic.

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