scholarly journals Redox conditions of the deep ocean in the late Neoproterozoic-Early Paleozoic: 57Fe Moessbauer spectroscopic study on deep-sea pelagic chert

2009 ◽  
Vol 115 (8) ◽  
pp. 391-399 ◽  
Author(s):  
Tomohiko Sato ◽  
Yukio Isozaki ◽  
Motoyuki Matsuo
Keyword(s):  
Spectroscopic Study ◽  
Deep Sea ◽  
Deep Ocean ◽  
Redox Conditions ◽  
Early Paleozoic ◽  
Late Neoproterozoic

scholarly journals Glacial – interglacial atmospheric CO<sub>2</sub> change: a simple "hypsometric effect" on deep-ocean carbon sequestration?

2006 ◽  
Vol 2 (5) ◽  
pp. 711-743 ◽  
Author(s):  
L. C. Skinner
Keyword(s):  
Carbon Sequestration ◽  
Carbon Storage ◽  
Ocean Circulation ◽  
Deep Water ◽  
Deep Sea ◽  
Storage Capacity ◽  
Deep Ocean ◽  
Contributing Factors ◽  
Carbon Reservoir ◽  
Ocean Carbon

Abstract. Given the magnitude and dynamism of the deep marine carbon reservoir, it is almost certain that past glacial – interglacial fluctuations in atmospheric CO2 have relied at least in part on changes in the carbon storage capacity of the deep sea. To date, physical ocean circulation mechanisms that have been proposed as viable explanations for glacial – interglacial CO2 change have focussed almost exclusively on dynamical or kinetic processes. Here, a simple mechanism is proposed for increasing the carbon storage capacity of the deep sea that operates via changes in the volume of southern-sourced deep-water filling the ocean basins, as dictated by the hypsometry of the ocean floor. It is proposed that a water-mass that occupies more than the bottom 3 km of the ocean will essentially determine the carbon content of the marine reservoir. Hence by filling this interval with southern-sourced deep-water (enriched in dissolved CO2 due to its particular mode of formation) the amount of carbon sequestered in the deep sea may be greatly increased. A simple box-model is used to test this hypothesis, and to investigate its implications. It is suggested that up to 70% of the observed glacial – interglacial CO2 change might be explained by the replacement of northern-sourced deep-water below 2.5 km water depth by its southern counterpart. Most importantly, it is found that an increase in the volume of southern-sourced deep-water allows glacial CO2 levels to be simulated easily with only modest changes in Southern Ocean biological export or overturning. If incorporated into the list of contributing factors to marine carbon sequestration, this mechanism may help to significantly reduce the "deficit" of explained glacial – interglacial CO2 change.

scholarly journals The Search for Supernova-Produced Radionuclides in Terrestrial Deep-Sea Archives

2012 ◽  
Vol 29 (2) ◽  
pp. 109-114 ◽  
Author(s):  
J. Feige ◽  
A. Wallner ◽  
S. R. Winkler ◽  
S. Merchel ◽  
L. K. Fifield ◽  
...  
Keyword(s):  
Solar System ◽  
Marine Sediment ◽  
Deep Sea ◽  
Massive Stars ◽  
Sediment Cores ◽  
Deep Ocean ◽  
Transport Mechanisms ◽  
Supernova Shell ◽  
Process Element ◽  
Insight Into

AbstractAn enhanced concentration of 60Fe was found in a deep ocean crust in 2004 in a layer corresponding to an age of ∼2 Myr. The confirmation of this signal in terrestrial archives as supernova-induced and the detection of other supernova-produced radionuclides is of great interest. We have identified two suitable marine sediment cores from the South Australian Basin and estimated the intensity of a possible signal of the supernova-produced radionuclides 26Al, 53Mn, 60Fe, and the pure r-process element 244Pu in these cores. The finding of these radionuclides in a sediment core might allow us to improve the time resolution of the signal and thus to link the signal to a supernova event in the solar vicinity ∼2 Myr ago. Furthermore, it gives us an insight into nucleosynthesis scenarios in massive stars, condensation into dust grains and transport mechanisms from the supernova shell into the solar system.

Deep-sea panoramas: Progress and remaining challenges in late Miocene stratigraphy and climate

2021 ◽  
Author(s):  
Anna Joy Drury ◽  
Thomas Westerhold ◽  
David A. Hodell ◽  
Mitchell Lyle ◽  
Cédric M. John ◽  
...  
Keyword(s):  
High Resolution ◽  
Ocean Circulation ◽  
Late Miocene ◽  
Deep Sea ◽  
Deep Ocean ◽  
High Resolution Data ◽  
Ongoing Work ◽  
Climate Evolution ◽  
Deep Ocean Circulation ◽  
Geological Timescale

&lt;p&gt;During the late Miocene, meridional sea surface temperature gradients, deep ocean circulation patterns, and continental configurations evolved to a state similar to modern day. Deep-sea benthic foraminiferal stable oxygen (&amp;#948;&lt;sup&gt;18&lt;/sup&gt;O) and carbon (&amp;#948;&lt;sup&gt;13&lt;/sup&gt;C) isotope stratigraphy remains a fundamental tool for providing accurate chronologies and global correlations, both of which can be used to assess late Miocene climate dynamics. Until recently, late Miocene benthic &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O and &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C stratigraphies remained poorly constrained, due to relatively poor global high-resolution data coverage.&lt;/p&gt;&lt;p&gt;Here, I present ongoing work that uses high-resolution deep-sea foraminiferal stable isotope records to improve late Miocene (chrono)stratigraphy. Although challenges remain, the coverage of late Miocene benthic &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O and &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C stratigraphies has drastically improved in recent years, with high-resolution records now available across the Atlantic and Pacific Oceans. The recovery of these deep-sea records, including the first astronomically tuned, deep-sea integrated magneto-chemostratigraphy, has also helped to improve the late Miocene geological timescale. Finally, I will briefly touch upon how our understanding of late Miocene climate evolution has improved, based on the high-resolution deep-sea archives that are now available.&lt;/p&gt;

A holistic vision for our future deep ocean

2020 ◽  
pp. 201-206
Author(s):  
Eva Ramirez-Llodra ◽  
Maria Baker ◽  
Paul Tyler
Keyword(s):  
Deep Sea ◽  
Natural Capital ◽  
Synergistic Effects ◽  
Deep Ocean ◽  
Scientific Data ◽  
National Jurisdiction ◽  
Industrial Solutions ◽  
Sound Management ◽  
Holistic Vision

Healthy oceans are essential to maintain a healthy planet, but the ocean is facing many challenges that need urgent attention. Robust scientific data and innovative technological, policy, and industrial solutions are essential to support sound management of the deep-ocean natural capital, both within and beyond national jurisdiction, to ensure future healthy and productive oceans. As with many systems on Earth, there is a delicate ecological balance in the deep ocean that must be maintained. Understanding the interactions of the different components of natural capital in the deep sea is complex, as many of the variables are interlinked and many have cumulative and synergistic effects on the ecosystem. Add to this the global and changing effects of climate change and ocean acidification, and legislators and managers have a tough job ahead to account for all of these issues when designing appropriate conservation measures. It is important that scientists work hand in hand with multiple stakeholders to identify issues and research needs that contribute to enhancing knowledge and the science needed for decision-making to help towards securing a healthy future for our deep-ocean ecosystems and their long-term natural capital.

Challenging the dipolar paradigm for Proterozoic Earth

2022 ◽  
Author(s):  
James W. Sears
Keyword(s):  
Magnetic Field ◽  
Geomagnetic Field ◽  
Inner Core ◽  
Ultraviolet B ◽  
Late Permian ◽  
Early Paleozoic ◽  
Thin Spherical Shell ◽  
Late Neoproterozoic ◽  
Geocentric Axial Dipole ◽  
Drift Path

ABSTRACT A robust, geology-based Proterozoic continental assembly places the northern and eastern margins of the Siberian craton against the southwestern margins of Laurentia in a tight, spoon-in-spoon conjugate fit. The proposed assembly began to break apart in late Neoproterozoic and early Paleozoic time. Siberia then drifted clockwise along the Laurussian margin on coast-parallel transforms until suturing with Europe in late Permian time. The proposed drift path is permitted by a geocentric axial dipole (GAD) magnetic field from Silurian to Permian time. However, the Proterozoic reconstruction itself is not permitted by GAD. Rather, site-mean paleomagnetic data plot ted on the reconstruction suggest a multipolar Proterozoic dynamo dominated by a quadrupole. The field may have resembled that of present-day Neptune, where, in the absence of a large solid inner core, a quadrupolar magnetic field may be generated within a thin spherical shell near the core-mantle boundary. The quadrupole may have dominated Earth’s geomagnetic field until early Paleozoic time, when the field became erratic and transitioned to a dipole, which overwhelmed the weaker quadrupole. The dipole then established a strong magnetosphere, effectively shielding Earth from ultraviolet-B (UV-B) radiation and making the planet habitable for Cambrian fauna.

Review of Deep-Ocean High-Pressure Simulation Systems

2020 ◽  
Vol 54 (3) ◽  
pp. 68-84
Author(s):  
Wentao Song ◽  
Weicheng Cui
Keyword(s):  
High Pressure ◽  
Coming Out ◽  
Deep Sea ◽  
Mathematical Theory ◽  
Deep Ocean ◽  
Cold Isostatic Pressing ◽  
Future Design ◽  
Stress Coefficient ◽  
History Of ◽  
Simulation Systems

AbstractDeep-sea technology and equipment are required to explore the oceans and utilize ocean resources in the 21st century. Deep-ocean simulation systems (DOSs) play an essential role in the development of deep-sea equipment. This paper gives a detailed overview of deep-ocean high-pressure simulation systems (DOHPSs) worldwide. First, the history of DOS is introduced, and then the primary available equipment, particularly coming out of China, is described. Next, the new concept of the cold isostatic pressing (CIP) chamber and its technology and equipment are reviewed. Then, the basic mathematical theory for the design of pressure chambers is introduced to illustrate the limitations of the traditional monobloc chamber. To easily understand the pre-stressed wire-wound (PSWW) design, the pre-stress coefficient is introduced in theoretical analysis. Some valuable researches of PSWW are presented. Finally, the sealing design of DOS, especially tooth-locked quick-actuating closures (TLQAC), is discussed. The paper aims to inspire readers to develop innovative ideas about the future design of DOS.

Depth Profiling Investigation of Seawater Using Combined Multi-Optical Spectrometry

2020 ◽  
Vol 74 (5) ◽  
pp. 563-570 ◽  
Author(s):  
Wangquan Ye ◽  
Jinjia Guo ◽  
Nan Li ◽  
Fujun Qi ◽  
Kai Cheng ◽  
...  
Keyword(s):  
Deep Sea ◽  
Depth Profiling ◽  
Deep Ocean ◽  
Euphotic Zone ◽  
Depth Resolution ◽  
Remotely Operated Vehicle ◽  
Sea Trial ◽  
Depth Profiles ◽  
Diving Depth ◽  
Optical Spectrometry

Depth profiling investigation plays an important role in studying the dynamic processes of the ocean. In this paper, a newly developed hyphenated underwater system based on multi-optical spectrometry is introduced and used to measure seawater spectra at different depths with the aid of a remotely operated vehicle (ROV). The hyphenated system consists of two independent compact deep-sea spectral instruments, a deep ocean compact autonomous Raman spectrometer and a compact underwater laser-induced breakdown spectroscopy system for sea applications (LIBSea). The former was used to take both Raman scattering and fluorescence of seawater, and the LIBS signal could be recorded with the LIBSea. The first sea trial of the developed system was taken place in the Bismarck Sea, Papua New Guinea, in June 2015. Over 4000 multi-optical spectra had been captured up to the diving depth about 1800 m at maximum. The depth profiles of some ocean parameters were extracted from the captured joint Raman–fluorescence and LIBS spectra with a depth resolution of 1 m. The concentrations of [Formula: see text] and the water temperatures were measured using Raman spectra. The fluorescence intensities from both colored dissolved organic matter (CDOM) and chlorophyll were found to be varied in the euphotic zone. With LIBS spectra, the depth profiles of metallic elements were also obtained. The normalized intensity of atomic line Ca(I) extracted from LIBS spectra raised around the depth of 1600 m, similar to the depth profile of CDOM. This phenomenon might be caused by the nonbuoyant hydrothermal plumes. It is worth mentioning that this is the first time Raman and LIBS spectroscopy have been applied simultaneously to the deep-sea in situ investigations.

scholarly journals RETRACTED ARTICLE: Novel life history strategy in a deep sea fish challenges assumptions about reproduction in extreme environments

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Randal A. Singer ◽  
Jon A. Moore ◽  
Edward L. Stanley
Keyword(s):  
Life History ◽  
Deep Sea ◽  
Extreme Environments ◽  
Life History Strategy ◽  
Deep Ocean ◽  
Homogeneous System ◽  
Life History Strategies ◽  
Life History Trait ◽  
Retracted Article ◽  
Sea Fish

Abstract The deep ocean is frequently assumed to be a homogeneous system lacking the same diverse life history strategies found in shallower waters. However, as our methods for exploring the deep ocean improve, common assumptions about dispersal, reproduction and behavior are constantly being challenged. Fishes exhibit the most diverse reproductive strategies among vertebrates. Understanding life history strategies in deep-sea environments is lacking for many species of fishes. Here, we report a novel reproductive strategy where a fish (Parazen pacificus) provides parental care via mouth brooding. This behavior is observed from a specimen collected with eggs present in the buccal cavity, along with other specimens exhibiting pre-brooding morphologies. This is the first description of this unique life history trait in a deep-sea fish and fills in a gap in the larval literature for this family of fishes and prompts further investigation into other novel reproductive modes of deep-sea fauna.

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