BBC News - Missing Malaysia plane: Search 'regains recorder signal'
"Other key points made by ACM Houston:
- Searchers have no idea what the sea bed looks like in the search area. They think it may be silty
- Silt is bad news. It can be thick and can hide things in a way that rock does not"
A second opinion:
http://iod.ucsd.edu/~amanda/Files/De...he%20World.pdf
"Owing to strong geostrophic currents and consequent scouring of the sediments, the Wharton Basin, the southern Mascarene Basin, and parts of the Southwest Indian and Australian–Antarctic Basins have little or no sediment (Kennett, 1982). Sediment in these areas, when present, is mostly brown clay."
"There are strong bottom currents, with speeds approaching 10–20 cm s−1, in the Wharton Basin and the southern Mascarene Basin, and in parts of the Southwest Indian Basin and Australian–Antarctic Basins, resulting in minimal sediment deposition (Kennett, 1982; Gage and Tyler, 1991)."
Kennett, J.P., 1982. Marine Geology. Prentice-Hall, Englewood Cliffs, NJ, 813 pp.
Same author claims that the
average depth, both in the Indian Ocean and world-wide, is nearly 4 km:
"The Indian Ocean, including adjacent seas (e.g., the Arabian Sea, the Bay of Bengal, and the Southern Ocean), covers 73 426 000 km2, roughly one-fifth of the total world oceanic area. It has an average depth of 3890 m, which is approximately equivalent to the average world-ocean depth."