They are interpreted as conical intrusions and can reach diameters of several kilometers and intrude thicknesses of several tens of meters ( Shoulders and Cartwright, 2004, Cartwright et al., 2008). Other conical features, rather than eroding, appear to “push up” a keystone of sediment above the regional level, sometimes generating forced folds. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this chapter). Note the presence of fossil pockmarks (white ellipse). In cross-sectional view, they erode previously deposited layers. ![]() Individual pockmarks appear as funnel-shaped depressions up to 1 km in diameter. (B) Cross section along the red line on the map. ![]() (A) Combination of seafloor bathymetry (colour scale) and dip to give a relief rendering. Pockmarks at the seafloor in the Gulf of Guinea (Angola). Many pockmarks at the Mediterranean seafloor are associated with gas saturated sediments and escaping methane bubbles ( Dupré et al., 2010 Praeg et al., 2014 Ingrassia et al., 2015 Rovere et al., 2020) ( Fig. 12.10B and C).įigure 10.22. However, the increasing use of high-resolution multibeam echosounders is most likely going to lead to the discovery of even more pockmarks and seep-related structures, regardless of their size. The threshold detection of multibeam is not always suitable to map small-scale pockmarks, giving therefore an incomplete view at the scale of the entire Mediterranean Sea. Pockmarks of various sizes are also observed in many other places, e.g., along the Mediterranean Ridge and Anaximander Mountains ( Dimitrov and Woodside, 2003) and in the Central Adriatic Sea ( Geletti et al., 2008 Pellegrini et al., 2018 Rovere et al., 2020). Pockmarks are numerous at the Mediterranean seafloor, with the main pockmark field located in the Central Nile deep-sea fan ( Loncke et al., 2004 Römer et al., 2014) ( Fig. 12.9A), as well as, offshore Israel ( Schattner et al., 2012) and in the western Alboran Sea ( Somoza et al., 2012). ![]() Stephanie Dupré, in Oceanography of the Mediterranean Sea, 2023 12.4.4 Pockmarks
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