Consulta: subjectFacets:"Nile Deep Sea Fan"
Registros recuperados: 5
Data/hora: 08/06/2024 17:50:17

High-resolution mapping of large gas emitting mud volcanoes on the Egyptian continental margin (Nile Deep Sea Fan) by AUV surveys
Provedor de dados: 5
Autores: Dupre, Stephanie; Buffet, G.; Mascle, J.; Foucher, Jean-paul; Gauger, S.; Boetius, A.; Marfia, Christian.
Two highly active mud volcanoes located in 990-1,265 m water depths were mapped on the northern Egyptian continental slope during the BIONIL expedition of R/V Meteor in October 2006. High-resolution swath bathymetry and backscatter imagery were acquired with an autonomous underwater vehicle (AUV)-mounted multibeam echosounder, operating at a frequency of 200 kHz. Data allowed for the construction of similar to 1 m pixel bathymetry and backscatter maps. The newly produced maps provide details of the seabed morphology and texture, and insights into the formation of the two mud volcanoes. They also contain key indicators on the distribution of seepage and its tectonic control. The acquisition of high-resolution seafloor bathymetry and acoustic imagery maps...
Tipo: Text
Palavras-chave: Eastern Mediterranean; Seafloor morphology; Backscatter; Bathymetry; AUV; Nile Deep Sea Fan; Mud volcanoes.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-6395.pdf

Menes caldera, a highly active site of brine seepage in the Eastern Mediterranean sea: "In situ" observations from the NAUTINIL expedition (2003)
Provedor de dados: 5
Autores: Huguen, Caroline; Foucher, Jean-paul; Mascle, J.; Ondreas, Helene; Thouement, M.; Gontharet, S.; Stadnitskaia, A.; Pierre, C.; Bayon, Germain; Loncke, L.; Boetius, A.; Bouloubassi, I.; De Lange, G.; Caprais, Jean-claude; Fouquet, Yves; Woodside, J.; Dupre, Stephanie.
This paper reports the first "in situ" seafloor observations of fluid escape structures in a fault-controlled caldera-type depression of about 8 km diameter, named the Menes caldera, in the Eastern Mediterranean sea off Egypt (western province of the Nile Deep Sea Fan). A detailed analysis of seven Nautile dives, performed during the Nautinil cruise in 2003, focused on determining the nature, origin, importance, mechanisms and environmental impacts of the fluid escape processes from the geological observations. Seafloor maps, constructed from direct visual observations and video records made from the submersible, and sampling results, for three mud volcanoes of the caldera, Cheops, Chephren and Mykerinos show differences in activity but many common...
Tipo: Text
Palavras-chave: Mediterranean Sea; Nile Deep Sea Fan; Mud volcano; Brine seep.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00000/11089/10627.pdf

Multi-scale seafloor mapping of active seep-related structures, offshore Egypt
Provedor de dados: 5
Autores: Dupre, Stéphanie; Woodside, John; Klaucke, Ingo; Mascle, Jean; Foucher, Jean-paul.
The Nile deep sea fan system presents a rich variety of fluid escape structures, gas chimneys, pockmarks and carbonate crust mounds, brines pools, and several types of mud volcano. These seep-related structures were explored for the first time with the Nautile submersible during the 2003 Nautinil expedition and are characterized by high thermal gradients and highly gas-saturated sediments. More recently, high resolution side scan sonar data acquired during the 2004 Mimes expedition brings more detail to the geophysical imagery. The EdgeTech DTS-1 deep tow sonar coupled with a 2-8 kHz chirp subbottom penetrator was deployed around 100 m above the seafloor and operated at a frequency of 75 kHz. Several gas plumes were acoustically detected in the water...
Tipo: Text
Palavras-chave: Free gas emission; Backscatter; Authigenic carbonate crust; Mud volcanism; Gas chimneys; Nile Deep Sea Fan.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2005/acte-6396.pdf

Widespread active seepage activity on the Nile Deep Sea Fan (offshore Egypt) revealed by high-definition geophysical imagery
Provedor de dados: 5
Autores: Dupre, Stephanie; Woodside, John; Klaucke, Ingo; Mascle, Jean; Foucher, Jean-paul.
Fluid escape structures on the Nile Deep Sea Fan were investigated during the MEDIFLUX MIMES expedition in 2004. Mud volcanoes, pockmarks and authigenic carbonate structures were surveyed for the first time with a high-resolution deep-towed 75 kHz sidescan sonar and a 2-8 kHz Chirp sediment echosounder. In combination with existing multibeam bathymetry and detailed seafloor in situ geological observations, these new data allowed detailed seep analyses. About 60 gas flares were detected acoustically in the water column from the sidescan sonar raw data at water depths from 770 to 1700 m. These gas flares coincide at the seabed with 1) the centres of the mud volcanoes where mud is also extruded, 2) the borders of the mud volcanoes where the emitted gases...
Tipo: Text
Palavras-chave: Nile Deep Sea Fan; Seepage; Backscatter; Sidescan sonar; High-resolution; Gas chimneys; Mud volcanoes; Authigenic carbonates.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00013/12457/9766.pdf

Microbial methane oxidation and sulfate reduction at cold seeps of the deep Eastern Mediterranean Sea
Provedor de dados: 5
Autores: Omoregie, Enoma O.; Niemann, Helge; Mastalerz, Vincent; De Lange, Gert J.; Stadnitskaia, Alina; Mascle, Jean; Foucher, Jean-paul; Boetius, Antje.
The Eastern Mediterranean hosts a variety of active cold seep systems, such as gas chimneys, mud volcanoes and pockmarks, in water depths of 500 to 3200 m. As part of the NAUTINIL expedition in 2003, the sediments of cold seeps on the Nile Deep Sea Fan (NDSF) were sampled for the first time for biogeochemical and microbiological analyses. Here we compare rates of the anaerobic oxidation of methane (AOM) and sulfate reduction (SR) as well as the microbial community structure of a variety of cold seep systems including mud volcanoes, pockmarks and brine seeps. Our results revealed strong differences in microbial activity among the different seep systems of the Eastern, Central and Western provinces of the NDSF, as well as the Olimpi field (Central...
Tipo: Text
Palavras-chave: Methane oxidation; Sulfate reduction; Archaea; Cold seeps; Mud volcano; Pockmarks; Nile Deep Sea Fan.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00000/11087/7910.pdf