  Near surface seafloor properties are needed for recreational, commercial, and
military applications. Construction projects on the ocean seafloors often
require extensive knowledge about strength, deformability, hydraulic, thermal,
acoustic, and seismic characteristics for locating stable environments and
ensuring proper functioning of structures, pipelines, and other installations
on the surface of and buried into the marine sediments. The military is also
interested in a variety of seafloor properties as they impact sound
propagation, mine impact burial, trafficability, bearing capacity,
time-dependent settlement, and stability of objects on the seafloor. Point
measurements of sediment properties are done using core samplers and sediment
grab devices (with subsequent lab analysis) and in-situ probes. These
techniques are expensive in terms of ship time and provide limited area
coverage. Sub-bottom acoustic and electromagnetic sensors can provide profiles
of near surface sediment information with improved coverage rates. Fusion
techniques are being developed to provide areal extent of sediment information
from multiple sensors. This paper examines the recent history of techniques
used to measure sediment properties in the upper portions of the seafloor and
in shallow (<100m) water.
