standardization of environmental data and information - International ...

1. Sediment Properties
Sediment properties are important for understanding sediment
resuspension and transport of the plume as well as providing supporting
information for benthic and chemical studies. The Working Group agreed
with the LTC commentary on the key parameters to be investigated: specific
gravity, bulk density, water content (porosity), shear strength, grain size and
distribution, depth of the redox boundary, organic and inorganic carbon
content, chemical composition and bioturbation depth (table 1). For several
of these parameters no one standard method of analysis exists, nor could
the Working Group agree on a preferred method. It is recommended that
any one of several common, state-of-the-art methods be used. In addition,
these methodological gaps are identified as potential community-wide
issues (see the Workshop report in chapter 22 above, section 6).
It is recommended that, in wet sieving for grain-size analysis,
seawater should be used and no chemical detergents should be added.
This will result in larger grain sizes, but should more closely approximate the
nature of the suspended sediment plume.
As sedimentation rates in claim areas are generally considered very
low, they were determined not to be an important parameter and they have
therefore been excluded from the list of key parameters.
It is recommended that the parameters cited in table 1 be
measured at the following core-depth intervals: 0-1, 1-3, 3-5, 5-8, 8-12 and
12-20 centimetres.
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INTERNATIONAL SEABED AUTHORITY