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The Navy's classified colleclion of bottom sediments and 

 cores available in a relational database could augment the 

 Ocean Drilling Program worldwide data set. Applications of 

 interest include the construction of highly accurate geological 

 maps to provide an extension of onshore mapping, an 

 environmental baseline, and a guide for natural resources 

 exploration. The descriptions of the physical composition and 

 grain size distribution of the sediments could help commercial 

 users locate oil-saturated sediments, locate titanium and 

 manganese deposits, and map salt domes, which can act as 

 petroleum traps or influence migration pathways. Composite 

 records of the distribution of sediments (like the LFBL sediment 

 thickness data) could assist in the study of sea bottom processes 

 such as current activity, erosion, and deposition. 



C. SEA ICE 



1. HISTORICAL ICE MORPHOLOGY 



a. Data Description 



Temporal records of Arctic ice extent, ice type, ice drift, and ice 

 draft are collected and stored in Navy classified archives. The 

 Navy's interest in ice is related to its operations at northern 

 latitudes where sea ice can be both a hazard and a haven. The 

 ice provides both an optical and acoustical cover for submarines, 

 and die operation of surface ships is constrained by ice boundaries 

 and drift. Ice thickness is important for submarine operation in 

 the Arctic region since under-ice safety is related to knowing 

 where the thinner ice might be found or where deep ice keel 

 obstructions exist. 



The thickness of sediment deposits near coastlines provides 

 important constraints on the nature of the evolution of continental 

 margins that are subject to the same thermal decay, loading, 

 and elastic flexure as the seafloor. Seismologists observe low 

 frequency surface waves that propagate across the ocean basins 

 and continental margins, but do not have access to global maps 

 of sediment thickness to use in estimating its effect on the 

 dispersion characteristics of the modes. 



d. Findings 



The findings relative to seafloor sediment (soperties are: 



• The Navy's global ocean sediment thickness database is 

 unclassified, though it has net been generally accessible. Its 

 value and uniqueness strongly support the conclusion that it 

 should be publicly distributed. 



• The associated seafloor sediment type database should also 

 be made publicly available. 



• The bottom sediments data can be of use to geophysicists for 

 studies of the solid earth, including investigations of seismic 

 wave propagation. 



• Geological maps constructed with these data as well as 

 extensions to onshore mapping can provide data for 

 environmental business, natural resource exploration, and 

 paleo-productivity assessments. 



A particularly impressive data set available at the National Ice 

 Center (NIC) is a detailed historical analysis of sea ice conditions 

 over the Arctic Outer Continental Shelf This data set provides 

 a decade of ice observations prior to the launch of LANDSAT 

 in 1 972 and is the result of an inventive compilation from a wide 

 variety of data sources. There is an excellent chance that this 

 data set is superior to any compiled set available elsewhere. 

 These data exist in the form of hand drawn charts exhibiting ice 

 edge and ice condition information compiled from a variety of 

 classified and unclassified sources. 



Figure 12 (unclassified) shows the minimum and maximum 

 extent of ice edges. The Navy's classified Historical Ice 

 Morphology charts cannot be shown here, but their contents are 

 primarily depictions of the ice edge and ice conditions 

 (concentration, type, etc.) in hand-drawn chart format with a 

 temporal granularity of one week. 



The well-known mean drift of Arctic ice is illustrated in 

 Figure 13. Arrows represent the direction ofthe ice drift across 

 the Arctic Basin, with the speed being proportional to the length 

 of the arrow. This Arctic ice drift, combined with the seasonal 

 effects of warming/cooling and variable snow cover, will 

 require much more granularity for depicting ice conditions, 

 should scientific research into topics like climate warming be 

 initiated. 



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