DEVELOPMENT OF AN IN-SITU SEDIMENT VELOCIMETER.
COLUMBIA UNIV DOBBS FERRY N Y HUDSON LABS
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Deep ocean bottom measurements have previously been an area of investigation largely reserved for theoretical studies, wire line instrumentation, and indirect measurement. In addition, the measurement standards and procedures for laboratory analysis of artificial and natural sediments are not directly applicable to the more complex marine environment. Some deep water in-situ measurements of marine sediments have been made with the bathyscaph Trieste, but these have been widely spaced with many gaps in the environmental record. To augment ocean bottom interpretive data with direct measurement, Hudson Laboratories in conjunction with the Benthos Company has developed an in-situ sediment velocimeter. The basic unit is a free-fall device instrumented with transducers and core sampler. The unit is released at the surface and free falls through the water column and implants three probes in the sediment to a depth of 48 cm. Since the unit is activated before release into the water, a recording of compressional wave velocity is made during free fall through the water column and subsequent penetration into the bottom. A sequential timer electrically separates the buoyant section from the free fall vehicle and withdraws the transducers and the core sample from the bottom and returns the recording system to the surface.
- Physical and Dynamic Oceanography