Shallow Gas Hydrates Associated to Pockmarks in the Northern Congo Deep-Sea Fan, SW Africa

2022 ◽  
pp. 359-371
Author(s):  
Thomas Pape ◽  
Gerhard Bohrmann
Keyword(s):  
Gas Hydrates ◽  
Deep Sea ◽  
Shallow Gas ◽  
Sea Fan

Numerical Simulation of Deep Sea Gas Hydrate Plumes

2014 ◽  
Vol 1010-1012 ◽  
pp. 1719-1722
Author(s):  
Zhi Li Hua ◽  
Zhong Hai Zhou
Keyword(s):  
Gas Hydrates ◽  
Deep Sea ◽  
Bubble Radius ◽  
Gas Bubble ◽  
Acoustic Detection ◽  
Acoustic Features ◽  
Shallow Gas ◽  
The World ◽  
Simulation Results ◽  
Development Area

Plume is closely related to the presence of gas hydrates which can often be found in plume development area. By acoustic detection, plumes of bubbles in the seawater from shallow gas have been found by marine surveying instruments in some areas over the world. Based on the existed theory of plume porosity, acoustic echo profile of sedbed seep plumes are numerically calculated. Within the simulation results, according to the pattern of gas bubble change and movement in the seawater, process of methane plumes generation is simulated and directs the distribution of bubble radius and plume boundary as depth. Acoustic features of plume bubbles seeping from shallow gas are shown to be consistent with the field results.

scholarly journals Gas seeps and gas hydrates in the Amazon deep-sea fan

2018 ◽  
Vol 38 (5) ◽  
pp. 429-438 ◽  
Author(s):  
Joao Marcelo Ketzer ◽  
Adolpho Augustin ◽  
Luiz Frederico Rodrigues ◽  
Rafael Oliveira ◽  
Daniel Praeg ◽  
...  
Keyword(s):  
Gas Hydrates ◽  
Deep Sea ◽  
Sea Fan ◽  
Gas Seeps

scholarly journals Marine gas hydrates’ evolution after Middle Pleistocene: basin analysis of the Danube fan, Black Sea

2020 ◽  
Vol 81 (3) ◽  
pp. 184-186
Author(s):  
Atanas Vasilev ◽  
Nikola Botoucharov ◽  
Petar Petsinski ◽  
Rositsa Pehlivanova
Keyword(s):  
Black Sea ◽  
Gas Hydrates ◽  
Gas Hydrate ◽  
Deep Sea ◽  
Geological Structure ◽  
Basin Analysis ◽  
Middle Pleistocene ◽  
The Black Sea ◽  
Sea Fan

The aim of this work is to reconstruct the variations of the total gas hydrate (GH) masses of the Danube deep-sea fan after 0.265 Ma BP. The PetroMod™ model developed in GEOMAR, Germany is for basin analysis of the Western Black Sea for 98 Ma. Geological structure is from 2D seismic of the Black Sea consortium “Geology without limits”. Results show a trend for total GH masses decrease after Middle Pleistocene and the role of the GHs as sink and source of methane.

scholarly journals Stratigraphic revision and reconstruction of the deep-sea fan of the Voirons Flysch (Voirons Nappe, Chablais Prealps)

2021 ◽  
Vol 114 (1) ◽  
Author(s):  
Jérémy Ragusa ◽  
Lina Maria Ospina-Ostios ◽  
Pascal Kindler ◽  
Mario Sartori
Keyword(s):  
Deep Sea ◽  
Distal Part ◽  
Accretionary Prism ◽  
Proximal Part ◽  
Late Eocene ◽  
Lithostratigraphic Units ◽  
Stratigraphic Record ◽  
Sea Fan ◽  
Stratigraphic Evolution ◽  
Depositional Setting

AbstractThe Voirons Flysch (Caron in Eclogae Geologicae Helvetiae 69:297–308, 1976), is a flysch sequence aggregated into the sedimentary accretionary prism of the Chablais and Swiss Prealps. Its palaeogeographic location is still debated (South Piemont or Valais realm). We herein present a stratigraphic revision of the westernmost unit of the former Gurnigel Nappe sensu Caron (Eclogae Geologicae Helvetiae 69:297–308, 1976): the Voirons Flysch. This flysch is subdivided into three lithostratigraphic units at the formation level (the Voirons Sandstone, the Vouan Conglomerate, the Boëge Marl), with an additional unit (Bruant Sandstone) of uncertain attribution, ranging from the early Eocene to probably the late Eocene. We further propose a new model of the depositional setting of the deep-sea of the Voirons Flysch based on palaeocurrent directions, the overall geometry and sedimentary features. This model depicts an eastward deflected deep-sea fan. The stratigraphic record of the proximal part of this fan is fairly complete in the Voirons area, whereas its most distal part is only represented by one small exposure of thinly bedded sandstones in the Fenalet quarry. The stratigraphic evolution of the Voirons Flysch shows two major disruptions of the detrital sedimentation at the transition between Voirons Sandstone—Vouan Conglomerate and Vouan Conglomerate—Boëge Marl. The cause of these disturbances has to be constrained in the framework of the palaeogeographic location of the Voirons Flysch.

The ancestral Mississippi drainage archived in the late Wisconsin Mississippi deep-sea fan

Geology ◽  
2016 ◽  
Vol 44 (6) ◽  
pp. 479-482 ◽  
Author(s):  
A. Fildani ◽  
M.P. McKay ◽  
D. Stockli ◽  
J. Clark ◽  
M.L. Dykstra ◽  
...  
Keyword(s):  
Deep Sea ◽  
Sea Fan

scholarly journals Relative Abundance and Diversity of Bacterial Methanotrophs at the Oxic–Anoxic Interface of the Congo Deep-Sea Fan

2017 ◽  
Vol 8 ◽  
Author(s):  
Sandrine Bessette ◽  
Yann Moalic ◽  
Sébastien Gautey ◽  
Françoise Lesongeur ◽  
Anne Godfroy ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Deep Sea ◽  
Abundance And Diversity ◽  
Sea Fan

Two new species of Cossura (Cossuridae, Annelida) from the terminal lobes of the Congo River deep-sea fan

2017 ◽  
Vol 97 (5) ◽  
pp. 881-888
Author(s):  
Anna Zhadan
Keyword(s):  
New Species ◽  
Deep Sea ◽  
Anterior Margin ◽  
Posterior Part ◽  
Entire Body ◽  
Congo River ◽  
Two New Species ◽  
Dark Pigmentation ◽  
Sea Fan ◽  
Scanning Electron

Two new species of Cossura Webster & Benedict, 1887 were found in material collected during sampling from the terminal lobes of the Congo deep-sea fan. They were described using light and scanning electron microscopy. Cossura platypus sp. nov. has 15–17 thoracic chaetigers, a prostomium longer than it is wide, with a widely rounded anterior margin, an abruptly expanded posterior prostomial ring the same length as the peristomium, without a mid-ventral notch, a branchial filament attached to the midlength of chaetiger 3, and a pygidium with three anal cirri. Cossura platypus sp. nov. is similar to C. brunnea Fauchald, 1972 but differs in the shape of the prostomium, which is widely rounded anteriorly in C. platypus sp. nov. and is broadly triangular in C. brunnea; furthermore, C. platypus sp. nov.is uniformly pale, whereas C. brunnea has dark pigmentation. Cossura candida Hartman, 1955 differs from C. platypus sp. nov. in the conical shape of the prostomium and 24–35 thoracic chaetigers. Cossura flabelligera sp. nov. has 16–19 thoracic chaetigers, a conical prostomium, and a branchial filament arising from the posterior part of chaetiger 2; the entire body, including the chaetae, is covered by a thick mucous sheath similar to the tunic of flabelligerids. Cossura flabelligera sp. nov. resembles C. longocirrata Webster & Benedict, 1887 in the position of the branchial filament, the shape of the prostomium, and the number of thoracic chaetigers; it differs in having a thick mucous sheath. This character seems to be unique for the Cossuridae.

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