Sea-Floor Sunday #30: Submarine channels, deep-water Nigeria

In case you missed it, check out my post from last week about a relatively new online source of geoscience information and images, the Virtual Seismic Atlas.

One of the coolest parts of a 3D seismic-reflection survey is the very detailed map of the sea floor.

This image is a perspective image of the sea floor in deep water offshore the Niger Delta. The most prominent features are the submarine channels cutting across the slope. Also note the narrow ridge that is roughly perpendicular to the channel trend (near the green-gray boundary by color). These ridges are compressional features caused by folding and thrust-faulting of the underlying sediment. The upper part of the slope on continental margin deltas such as the Niger will typically have extensional (i.e., normal) faults - in deeper water near the lower slope or base-of-slope, that updip extension is balanced by a compressional zone. Also note the scale of these submarine channel systems (scale bar on lower left) ... these suckers are big.

Here's the blurb about this image directly from the VSA site:

Sea bed images derived from 3D seismic for part of deep-water Western Niger Delta. The submarine canyons carve through ridges that are underlain by anticlines that represent part of the deep-water fold thrust belt. Various generations of canyons can be identified on the basis of cross-cutting relationships.

See the original image from VSA here.

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