Results 201 to 210 of about 6,266 (245)

Terrain aided underwater navigation using pockmarks

OCEANS 2009, 2009
Terrain aided navigation techniques are attractive for obtaining submerged position fixes for an underwater vehicle. However, their use is dependent on a certain degree of variation in the terrain. This paper investigates the performance of terrain navigation algorithms in an area with pockmarks, i.e.
Kjetil Bergh Anonsen, Ove Kent Hagen
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Deep sea pockmark environments in the eastern Mediterranean

Marine Geology, 2003
A great number of circular to isometric depressions have been observed on the deep water seafloor in the eastern Mediterranean by MAK-1 and ORETech deep-tow side-scan sonar during several TTR cruises of the UNESCO Floating University Program since 1993, and also by visual observations made during the late 1998 French-Dutch MEDINAUT expedition.
Dimitrov, L., Woodside, J.M.
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New statistical methods for investigating submarine pockmarks

Computers & Geosciences, 2011
We investigate the applicability of some novel spatial analysis techniques, developed for studies of astrophysical datasets, to the analysis of spatial point data in sedimentary basins. The techniques are evaluated and compared with standard methods using two test areas that contain large numbers of submarine pockmarks developed in distributed arrays ...
Annabel Cartwright, Jennifer Moss, Joe Cartwright   +2 more
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P-wave velocity anisotropy in an active methane venting pockmark: The Scanner Pockmark, northern North Sea

2020
<p>Scanner pockmark is an active and continuous methane venting seafloor depression of ~ 900 x 450 m wide and 22 m deep. It is located in the northern North Sea, within the Witch Ground basin where the seafloor and shallow sediments are heavily affected by pockmarks and paleo-pockmarks of various sizes.
Gaye Bayrakci, Timothy A. Minshull, Jonathan M. Bull, Timothy J. Henstock, Giuseppe Provenzano, Hamza Birinci, Calum Macdonald, Robert Dunn   +7 more
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Evaluating the Hazard Potential of Pockmarks

OCEANS 81, 1981
Shallow crater-like depressions called pockmarks are known to occur in many parts of the world. Interest in pockmarks has been aroused by uncertainty of their exact mode and rate of formation, and the possibility that they might pose a threat to offshore installations.
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Giant pockmarks in a carbonate platform (Maldives, Indian Ocean)

Marine Geology, 2011
Circular structures and depressions in carbonate platforms are known to represent karst chimneys or sinkholes which form as a response to rock solution. This formation mechanism is plausible for shallow-water carbonates which lie in the reach of meteoric diagenesis or fresh-water lenses.
Betzler, C., Lindhorst, S., Hübscher, C., Lüdmann, T., Fürstenau, J., Reijmer, J.J.G.   +5 more
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Pockmarks of the Northwestern Arabian Gulf

1986
Pockmarks are natural bottom features, unrelated to production activities. Physical evidence for the origin of pockmarks from three sites in the northwestern Arabian Gulf is examined. Three related features are also discussed. Two sources of gases are suggested by the physical evidence.
Jeffrey P. Ellis, William T. McGuinness
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Pockmarks in Passamaquoddy Bay, New Brunswick, Canada

Geological Society, London, Memoirs, 2016
Pockmarks are seafloor depressions associated with fluid escape (Judd & Hovland 2007). They proliferate in the muddy seafloors of coastal Gulf of Maine and Bay of Fundy, where they are associated with shallow natural gas likely of biogenic origin (Ussler et al. 2003; Rogers et al. 2006; Wildish et al. 2008).
Brothers, L. L., Legere, C., Hughes Clarke, John E., Kelley, J. T., Barnhardt, W. A., Andrews, B. D., Belknap, D. F.   +6 more
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Pockmarks on the Mendeleev Rise, central Arctic Ocean

Geological Society, London, Memoirs, 2016
Circular to semi-circular crater-like depressions in the seafloor are commonly referred to as pockmarks. Pockmarks were discovered in the 1960s on echo-sounding profiles from the Scotian Shelf, eastern Canada (King & MacLean 1970). While there is no consensus regarding their formation process, pockmarks are in general linked to the removal of soft ...
M. Jakobsson, M. O'Regan
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Formation of pockmarks by pore-water escape

Geo-Marine Letters, 1985
During the course of a North Sea rig site investigation, a number of seabed depressions were observed on side-scan sonar records, some of which may be identified as pockmarks. Others are described as pits. A pockmark evolutionary series is proposed on the basis of all these features with a suggested mechanism which would favor release of pore water ...
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