News

Temporal and spatial variability in hydrography and dissolved oxygen along southwest Nova Scotia using glider observations

Abstract. 

"Dissolved oxygen (DO) in the global ocean is on the decline, resulting in the degradation of coastal habitats. As aquaculture production occurs in these regions, proper understanding of coastal DO dynamics is important for improved farm management (e.g. site selection). The main objective of this study was to quantify along-shore and cross-shore variability in DO dynamics, as well as onshore advection of offshore waters to the bays that could contain aquaculture farms. [...]".

 

Source: Science Direct 
Authors: Meredith Burke et al.
DOI: https://doi.org/10.1016/j.csr.2022.104908

Read the full article here.


Spatial heterogeneity in benthic foraminiferal assemblages tracks regional impacts of paleoenvironmental change across Cretaceous OAE2

Abstract. 

"The impact of global climate events on local ecosystems can vary spatially. Understanding this potential heterogeneity can illuminate which environments will be most impacted and the proximal drivers of ecosystem responses. Cenomanian–Turonian marine deposits of the Western Interior Seaway (WIS) record paleoceanographic changes associated with the Greenhorn transgression and the onset of Oceanic Anoxic Event 2 (OAE2). They provide an ideal setting to study basin-wide paleoecological responses during a global perturbation. [...]".

 

Source: Cambridge University Press
Authors: Raquel Bryant & Christina L. Belanger
DOI: https://doi.org/10.1017/pab.2022.47

Read the full article here.


Marine bioturbation collapse during Early Jurassic deoxygenation: implications for post-extinction marine ecosystem functioning

Abstract. 

"Climate change is undermining the health and integrity of seafloor ecosystems, with declines in bioturbation expected to impact future ecosystem functioning. We explored changes in the nature and degree of bioturbation during Early Jurassic global warming and ocean deoxygenation. Understanding how these communities responded can help anticipate how bioturbation and ecosystem functioning might change over large spatial and temporal scales. Trace and body fossils from outcrop and core in the Cleveland Basin, UK show how healthy seafloor communities deteriorated through the Pliensbachian spinatum Zone, and macroinfaunal behaviour [...]".

 

Source: Geological Society of London
Authors: Bryony A. Caswell & Liam Herringshaw
DOI: https://doi.org/10.1144/SP529-2022-226

Read the full article here.


No evidence for expansion of global ocean euxinia during the base Stairsian mass extinction event (Tremadocian, Early Ordovician)

Abstract.

"A Tremadocian (Early Ordovician, base Stairsian North American Stage) mass extinction event is recorded globally in rocks from several ancient continents and is accompanied by a globally correlated positive carbon isotope excursion (CIE; the largest during the Early Ordovician). In this study, elemental concentrations and uranium isotope compositions (δ238U) were measured for carbonate samples from three sections (along a proximal-to-distal transect: Ibex area, Shingle Pass, Meiklejohn Peak, respectively) in the Great Basin to test the role of ocean anoxia/euxinia on the base Stairsian mass extinction event. [...]".

 

Source: Science Direct 
Authors: Xinze Lu et al. 
DOI: https://doi.org/10.1016/j.gca.2022.11.028

Read the full article here.


Vanadium isotope evidence for widespread marine oxygenation from the late Ediacaran to early Cambrian

Abstract. 

"Early animals experienced multiple-phase radiations and extinctions from the late Ediacaran to early Cambrian. Oxygen likely played an important role in these evolutionary events, but detailed marine redox evolution during this period remains highly debated. The emerging vanadium (V) isotope system can better capture short-term perturbations to global ocean redox conditions. In this study, we analyzed V isotope compositions [...]".

 

Source: Science Direct 
Authors: Wei Wei et al.
DOI: https://doi.org/10.1016/j.epsl.2022.117942

Read the full article here.


Subpolar gyre decadal variability explains the recent oxygenation in the Irminger Sea

Abstract. 

"Accurate monitoring of the long-term trend of oxygen content at global scale requires a better knowledge of the regional oxygen variability at interannual to decadal time scale. Here, we combined the Argo dataset and repeated ship-based sections to investigate the drivers of the oxygen variability in the North Atlantic Ocean, a key region for the oxygen supply into the deep ocean. We focus on the Labrador Sea Water in the Irminger Sea over the period 1991–2018 and we show that the oxygen solubility explains less than a third of the oxygen variability. [...]".

 

Source: Nature
Authors: Charlène Feucher et al.
DOI: https://doi.org/10.1038/s43247-022-00570-y

Read the full article here.


Authigenic uranium deposition in the glacial North Atlantic: Implications for changes in oxygenation, carbon storage, and deep water-mass geometry

Abstract.

"Oxygen in the ocean has essential ecological and climatic functions, and can be an important indicator of deep-ocean ventilation and carbon storage. Previous studies are divided on whether the subsurface North Atlantic, which today is well-oxygenated, had higher or lower oxygen levels during the Last Glacial Maximum (LGM). Crucially, the limited number of previous reconstructions precludes any conclusions regarding basin-wide patterns in past changes in oxygenation. [...]".

 

Source: Science Direct 
Authors: Yuxin Zhou & Jerry F. McManus
DOI: https://doi.org/10.1016/j.quascirev.2022.107914

Read the full article here.


Shallow- and deep-ocean Fe cycling and redox evolution across the Pliensbachian–Toarcian boundary and Toarcian Oceanic Anoxic Event in Panthalassa

Abstract.

"The late Pliensbachian to early Toarcian was characterized by major climatic and environmental changes, encompassing the early Toarcian Oceanic Anoxic Event (T-OAE, or Jenkyns Event, ∼183 Ma) and the preceding Pliensbachian–Toarcian boundary event (Pl/To). Information on seawater redox conditions through this time interval has thus far come mainly from European sections deposited in hydrographically restricted basins, and hence our understanding of the redox evolution of the open ocean (and in particular Panthalassa – the largest ocean to have existed) is limited. [...]".

 

Source: Science Direct 
Authors: Wenhan Chen et al.
DOI: https://doi.org/10.1016/j.epsl.2022.117959

Read the full article here.


Sedimentary molybdenum and uranium: Improving proxies for deoxygenation in coastal depositional environments

Abstract. 

"Sedimentary molybdenum (Mo) and uranium (U) enrichments are widely used to reconstruct changes in bottom water oxygen conditions in aquatic environments. Until now, most studies using Mo and U have focused on restricted suboxic-euxinic basins and continental margin oxygen minimum zones (OMZs), leaving mildly reducing and oxic (but eutrophic) coastal depositional environments vastly understudied. Currently, it is unknown: (1) to what extent Mo and U enrichment factors (Mo- and U-EFs) can accurately reconstruct oxygen conditions in coastal sites experiencing mild deoxygenation, and (2) to what degree secondary [...]". 

 

Source: Science Direct 
Authors: K. Mareike Paul et al.
DOI: https://doi.org/10.1016/j.chemgeo.2022.121203

Read the full article here.


Calcium isotope ratios of malformed foraminifera reveal biocalcification stress preceded Oceanic Anoxic Event 2

Abstract. 

"Ocean acidification causes biocalcification stress. The calcium isotope composition of carbonate producers can archive such stress because calcium isotope fractionation is sensitive to precipitation rate. Here, we synthesize morphometric observations of planktic foraminifera with multi-archive calcium isotope records from Gubbio, Italy and the Western Interior Seaway spanning Cretaceous Ocean Anoxic Event 2 (~94 million years ago). Calcium isotope ratios increase ~60 thousand years prior to the event. [...]". 

 

Source: Nature
Authors: Gabriella D. Kitch et al.
DOI: https://doi.org/10.1038/s43247-022-00641-0

Read the full article here.


Showing 1 - 10 of 847 results.
Items per Page 10
of 85

Newsletter

It is possible to subscribe to our email newsletter list.

Depending on the amount of publications, we will summarize the activities on this blog in a newsletter for everyone not following the blog regularly.

If you want to subscribe to the email list to receive the newsletter, please send an email to sfb754@geomar.de with the header "subscribe".

If you want to unsubscribe from the newsletter, please send an email to sfb754@geomar.de with the header "unsubscribe".

You cannot forward any messages as a regular member to the list. If you want to suggest new articles or would like to contact us because of any other issue, please send an email to sfb754@geomar.de.