3D seismic evidence of internal structure within Tampen Slide deposits on the North Sea Fan: are chaotic deposits that chaotic?

Abstract

The seismic character of slide deposits is typically described as structureless or chaotic. However, 3D seismic data from the northern flank of the North Sea Fan reveal recognizable internal, penetrative structures within the Tampen Slide deposits. The study of its seismic attributes allowed an integrated characterization of the slide deposits and has shown distinctive acoustic fabrics, both at the top and base of the slide deposit, which are interpreted to be the expression of internal deformation structures. Based on their geometry, four main seismic fabric types have been defined: anastomosing, curvilinear, rectilinear and wispy. The spatial distribution of the fabric was mainly controlled by a topographic high present on the sea-bed at the time of the gravitational collapse, which influenced the transport of material. Areas of distinct fabrics are thought to reflect different flow behaviour during the latest stages of the mass movement and could be considered kinematic indicators. The results give new insights into the transport and deformation processes of submarine mass movements and highlight the potential of detailed analysis of 3D seismic data.

Submarine record of volcanic island construction and collapse in the Lesser Antilles arc: First scientific drilling of submarine volcanic island landslides by IODPExpedition 340

“…Expedition 340 IODP data confirm that chaotic units observed in seismic data do not necessarily represent extensively disaggregated or deformed material, which has been transported for long distances from the volcanic edifice [cf. Gafeira et al ., ]. It supports the view that extensive seafloor sediment failures may be relatively commonplace around volcanic islands [ Watt et al ., , 2014].…”

Structure and evolution of mass transport deposits in the South Caspian Basin, Azerbaijan

“…The internal structure of the mass transport deposit was imaged in three ways: (a) windowed root mean square (RMS) amplitude extractions taken through the mass transport deposit, using the bounding surfaces (basal shear surface or upper surface) as input horizons, or by (b) 3D attribute analysis (edge detection) of the seismic volume, and subsequent flattening and time slicing through the mass transport deposit using a bounding surface, or an adjacent surface as a datum (e.g. Frey‐Martinez & Cartwright, 2005; Moscardelli & Wood, 2008; Gafeira et al ., 2010), and by (c) dip magnitude maps taken along the basal shear surface (e.g. Posamentier & Kolla, 2003).…”

Widespread and progressive seafloor-sediment failure following volcanic debris avalanche emplacement: Landslide dynamics and timing offshore Montserrat, Lesser Antilles

“…Thus, in seismic data, chaotic intervals do not necessarily represent extensively disaggregated or deformed material, transported over long distances (cf. Gafeira et al, 2010).…”