scholarly journals Soluble, Colloidal, and Particulate Iron Across the Hydrothermal Vent Mixing Zones in Broken Spur and Rainbow, Mid-Atlantic Ridge

2021 ◽  
Vol 12 ◽  
Author(s):  
Mustafa Yücel ◽  
Serhat Sevgen ◽  
Nadine Le Bris
Keyword(s):  
Hydrothermal Vent ◽  
Near Field ◽  
Deep Ocean ◽  
Strong Acid ◽  
Hydrothermal Systems ◽  
Buoyant Plume ◽  
Particulate Iron ◽  
Bottom Waters ◽  
Mid Atlantic Ridge ◽  
Chemosynthetic Ecosystems

The slow-spreading Mid-Atlantic Ridge (MAR) forms geological heterogeneity throughout the ridge system by deep crustal faults and their resultant tectonic valleys, which results in the existence of different types of hydrothermal vent fields. Therefore, investigating MAR hydrothermal systems opens a gate to understanding the concentration ranges of ecosystem-limiting metals emanating from compositionally distinct fluids for both near-field chemosynthetic ecosystems and far-field transport into the ocean interiors. Here, we present novel data regarding onboard measured, size-fractionated soluble, colloidal, and particulate iron concentrations from the 2018 R/V L’Atalante – ROV Victor research expedition, during which samples were taken from the mixing zone of black smokers using a ROV-assisted plume sampling. Iron size fractionation (<20, 20–200, and >200nm) data were obtained from onboard sequential filtering, followed by measurement via ferrozine assay and spectrophotometric detection at 562nm. Our results showed the persistent presence of a nanoparticulate/colloidal phase (retained within 20–200nm filtrates) even in high-temperature samples. A significant fraction of this phase was retrievable only under treatment with HNO3 – a strong acid known to attack and dissolve pyrite nanocrystals. Upon mixing with colder bottom waters and removal of iron in the higher parts of the buoyant plume, the larger size fractions became dominant as the total iron levels decreased, but it was still possible to detect significant (micromolar) levels of nanoparticulate Fe even in samples collected 5m above the orifice in the rising plume. The coolest sample (<10°C) still contained more than 1μM of only nitric acid-leachable nanoparticle/colloidal, at least 200 times higher than a typical Fe concentration in the non-buoyant plume. Our results support previous reports of dissolved Fe in MAR vent plumes, and we propose that this recalcitrant Fe pool – surviving immediate precipitation – contributes to maintaining high hydrothermal iron fluxes to the deep ocean.

Microbial diversity in deep-sea sediments from the Menez Gwen hydrothermal vent system of the Mid-Atlantic Ridge

2015 ◽  
Vol 24 ◽  
pp. 343-355 ◽  
Author(s):  
Teresa Cerqueira ◽  
Diogo Pinho ◽  
Conceição Egas ◽  
Hugo Froufe ◽  
Bjørn Altermark ◽  
...  
Keyword(s):  
Microbial Diversity ◽  
Deep Sea ◽  
Hydrothermal Vent ◽  
Deep Sea Sediments ◽  
Mid Atlantic Ridge ◽  
Menez Gwen

Isocubanite-chalcopyrite intergrowths in the Mid-Atlantic Ridge 26°S hydrothermal vent sulfides

Geochemistry ◽  
2021 ◽  
pp. 125795
Author(s):  
Lei Fan ◽  
Guozhi Wang ◽  
Astrid Holzheid ◽  
Basem Zoheir ◽  
Xuefa Shi
Keyword(s):  
Hydrothermal Vent ◽  
Mid Atlantic Ridge

Ultrastructural characteristics of spermatogenesis in three species of deep-sea hydrothermal vent mytilids

1997 ◽  
Vol 75 (2) ◽  
pp. 308-316 ◽  
Author(s):  
Marcel Le Pennec ◽  
Peter G. Beninger
Keyword(s):  
Deep Sea ◽  
Hydrothermal Vent ◽  
The North ◽  
Male Gametes ◽  
Bathymodiolus Thermophilus ◽  
Nutritional Biology ◽  
Protandric Hermaphroditism ◽  
Mid Atlantic Ridge ◽  
Ultrastructural Characteristics ◽  
Species Specific

To enhance our understanding of the reproductive biology of deep-sea hydrothermal vent mytilids, the histology of the male gonad and the ultrastructure of its gametes were studied in Bathymodiolus thermophilus, B. puteoserpentis, and B. elongatus. Specimens of B. thermophilus were collected at the 13°N site on the East Pacific ridge, while B. puteoserpentis were sampled from the Snake Pit site of the mid-Atlantic ridge and B. elongatus were obtained from the North Fiji Basin. Gonad histology conformed to the typical bivalve profile; the differences in the proportions of acinal and interacinal tissue, as well as differences in acinal fullness in B. puteoserpentis, indicate that gametogenesis is discontinuous in these deep-sea mytilids. Evidence of protandric hermaphroditism was observed in B. elongatus, which exhibited acini containing both maturing and residual male gametes and immature oocytes. The ultrastructural characteristics of the male gametes conform to those described for littoral bivalve species, and the spermatozoon is of the primitive type. No species-specific differences in spermatozoon ultrastructure were discerned. No evidence of bacterial inclusions was found in either the gametes or the associated gonad cells in any of the species examined. The male gametes are thus probably not vectors for the endosymbiotic bacteria that characterize the nutritional biology of the adults in this genus.

Gaidropsarus mauli a new species of three-bearded rockling (Gadiformes, Gadidae) from the Lucky Strike hydrothermal vent field (Mid-Atlantic Ridge) and the Biscay Slope (Northeastern Atlantic)

Zootaxa ◽  
2018 ◽  
Vol 4459 (2) ◽  
pp. 301
Author(s):  
MANUEL BISCOITO ◽  
LUIZ SALDANHA
Keyword(s):  
New Species ◽  
Hydrothermal Vent ◽  
Valid Species ◽  
Lucky Strike ◽  
Pectoral Fins ◽  
Dorsal Fin ◽  
Fin Ray ◽  
Mid Atlantic Ridge ◽  
A New Species ◽  
Northeastern Atlantic

Gaidropsarus mauli, new species, is described from the Lucky Strike Hydrothermal vent site (Mid-Atlantic Ridge) and from the Bay of Biscay. It is distinguished from congeners by a combination of characters such as the number of vertebrae, the size of the first dorsal-fin ray, the profile of the head and the shape of the snout, in dorsal view, the size and the position of the eyes, the length of the pelvic fins, the shape of the pectoral fins, and the length of the lateral line. A comparison with the other 13 valid species of the genus is presented. 

Ferritin Crystals in the Gut Caeca of a Deep-Sea Hydrothermal Vent Stegocephalid (Crustacea: Amphipoda)

1997 ◽  
Vol 77 (1) ◽  
pp. 269-272 ◽  
Author(s):  
P.G. Moore ◽  
P.S. Rainbow
Keyword(s):  
Trace Metals ◽  
Hydrothermal Vent ◽  
Tectonic Activity ◽  
Amphipod Species ◽  
Single Pair ◽  
Thin Sections ◽  
Widespread Occurrence ◽  
X Ray ◽  
Mid Atlantic Ridge ◽  
High Concentrations

Ferritin crystals and calcium granules are reported from the ventral ceaca of Steleuthera ecoprophycea (Amphipoda: Stegocephalidae) collected from the Snake Pit hydrothermal vent, Mid-Atlantic Ridge (3520 m).In a series of earlier papers (Moore & Rainbow, 1984, 1989, 1992; Moore et al., 1994), the authors described the widespread occurrence of intracellular, octahedral crystals of ferritin in the ventral caeca of a range of stegocephalid amphipod species from the continental shelf epibenthos and oceanic plankton. The discovery at 3500 m of a new Steleuthera species (S. ecoprophycea), from a hydrothermal vent on the Mid-Atlantic Ridge was announced recently by Bellan-Santini & Thurston (1996), and a complete description is provided therein.Oceanic ridge sites are notable for their tectonic activity and the presence of a diversity of trace metals at high concentrations is to be expected in hydrothermal plumes emanating from such regions (German & Angel, 1995). The detoxification of accumulated trace metals in the ventral ceaca of stegocephalid amphipods from uncontaminated environments is now relatively well known (see above), so it was of interest to investigate whether a vent stegocephalid showed an atypical presence of trace metals in detoxified form in cells of the ventral caeca. The results following from an opportunity to investigate this are reported herein.Material was derived from a dive made by the submersible ‘Alvin’ at Snake Pit hydrothermal field, Mid-Atlantic Ridge (23°23′N 44°56′W), 3520 m, on 16 June 1993 (see Bellan-Santini & Thurston, 1996). Steleuthera ecoprophycea was preserved in 70% alcohol. Subsequently to dissection, the single pair of ventral caeca from each of the four damaged amphipods investigated were post-fixed in 4% glutaraldehyde. For electron microscopy and x-ray microanalysis in STEM mode, ventral caecal tissues were then dehydrated through 95% and absolute ethanol, cleared in propylene oxide, embedded in TAAB resin, sectioned at 0·5 μm (semi-thin sections) on a Reichert OmU2 ultramicrotome and examined without staining in a JEOL 100C electron microscope equipped with LINK system EDX energy dispersive x-ray microanalyser.

Far-field tsunami data assimilation for the 2015 Illapel earthquake

2019 ◽  
Vol 219 (1) ◽  
pp. 514-521 ◽  
Author(s):  
Y Wang ◽  
K Satake ◽  
R Cienfuegos ◽  
M Quiroz ◽  
P Navarrete
Keyword(s):  
Data Assimilation ◽  
Near Field ◽  
Source Parameters ◽  
Deep Ocean ◽  
Seismic Source ◽  
Far Field ◽  
Complementary Method ◽  
East Pacific ◽  
2015 Illapel Earthquake ◽  
Illapel Earthquake

SUMMARY The 2015 Illapel earthquake (Mw 8.3) occurred off central Chile on September 16, and generated a tsunami that propagated across the Pacific Ocean. The tsunami was recorded on tide gauges and Deep-ocean Assessment and Reporting of Tsunami (DART) tsunameters in east Pacific. Near-field and far-field tsunami forecasts were issued based on the estimation of seismic source parameters. In this study, we retroactively evaluate the potentiality of forecasting this tsunami in the far field based solely on tsunami data assimilation from DART tsunameters. Since there are limited number of DART buoys, virtual stations are assumed by interpolation to construct a more complete tsunami wavefront for data assimilation. The comparison between forecasted and observed tsunami waveforms suggests that our method accurately forecasts the tsunami amplitudes and arrival time in the east Pacific. This approach could be a complementary method of current tsunami warning systems based on seismic observations.

Transport of bottom waters through the Vema Fracture Zone in the Mid-Atlantic ridge

2007 ◽  
Vol 416 (1) ◽  
pp. 1120-1124 ◽  
Author(s):  
A. N. Demidov ◽  
S. A. Dobrolyubov ◽  
E. G. Morozov ◽  
R. Yu. Tarakanov
Keyword(s):  
Fracture Zone ◽  
Bottom Waters ◽  
Mid Atlantic Ridge
Sign in / Sign up

Export Citation Format

Share Document