Automated, objective texture segmentation of multibeam echosounder data - Seafloor survey and substrate maps from James Island to Ozette Lake, Washington Outer Coast

Without knowledge of basic seafloor characteristics, the ability to address any number of critical marine and/or coastal management issues is diminished. For example, management and conservation of essential fish habitat (EFH), a requirement mandated by federally guided fishery management plans (FMPs), requires among other things a description of habitats for federally managed species. Although the list of attributes important to habitat are numerous, the ability to efficiently and effectively describe many, and especially at the scales required, does not exist with the tools currently available. However, several characteristics of seafloor morphology are readily obtainable at multiple scales and can serve as useful descriptors of habitat. Recent advancements in acoustic technology, such as multibeam echosounding (MBES), can provide remote indication of surficial sediment properties such as texture, hardness, or roughness, and further permit highly detailed renderings of seafloor morphology. With acoustic-based surveys providing a relatively efficient method for data acquisition, there exists a need for efficient and reproducible automated segmentation routines to process the data. Using MBES data collected by the Olympic Coast National Marine Sanctuary (OCNMS), and through a contracted seafloor survey, we expanded on the techniques of Cutter et al. (2003) to describe an objective repeatable process that uses parameterized local Fourier histogram (LFH) texture features to automate segmentation of surficial sediments from acoustic imagery using a maximum likelihood decision rule. Sonar signatures and classification performance were evaluated using video imagery obtained from a towed camera sled. Segmented raster images were converted to polygon features and attributed using a hierarchical deep-water marine benthic classification scheme (Greene et al. 1999) for use in a geographical information system (GIS). (PDF contains 41 pages.

Sources And Cycling of Carbonyl Sulfide in the Sargasso Sea

The cycling of the radiatively important gas carbonyl sulfide (OCS) was studied in surface waters of the Sargasso Sea. In August 1999, surface OCS concentrations averaged 8.6 pmol L-1, showed minor diel variations, and varied little with depth. An OCS precursor, total dissolved organic sulfur (DOS), was lowest at the surface (40 nmol L-1) and increased with depth. The photoproduction rate of OCS from in situ incubations averaged 9.6 pmol L-1 h-1, whereas dark production was 7.0 pmol L-1 h-1. Apparent quantum yields were 10-5-10-7 from 313-436 nm and varied with the water depth irradiated. In March 2000, there were strong diel variations in surface OCS (highest in late afternoon; overall average, 16.9 pmol L-1). Depth profiles in the afternoon showed surface water maxima and decreases with depth, whereas DOS had a surface maximum of 419 nmol L-1 and decreased with depth. Dark production was 4.0 pmol L-1 h-1. Modeling of the diel cycle suggested a photoproduction rate of 16.4 pmol L-1 h-1. Overall, the photochemical production of OCS strongly depended on DOS and chromophoric dissolved organic matter, whereas dark production was influenced by the presence of particles and perhaps microbial respiration, showing a direct biotic influence on OCS cycling

Biogeochemistry of Arsenic and Antimony in the North Pacific Ocean

The biogeochemical cycles of the metalloid elements arsenic and antimony were examined along a 15,000 km surface water transect and at 9 vertical profile stations in the western North Pacific Ocean as part of the 2002 IOC Contaminant Baseline Survey. Results show that the speciation of dissolved arsenic (As III, As V, and methylated As) was subtly controlled by the arsenate (AsV)/phosphate ratio. An additional fraction of presumed organic arsenic previously reported in coastal waters was also present (~15% of the total As) in oceanic surface waters. Dissolved inorganic antimony displayed mildly scavenged behavior that was confirmed by correlations with aluminum, but atmospheric inputs that may be anthropogenic in origin also affected its concentrations. Monomethyl antimony, the predominant organic form of the element, behaved almost conservatively throughout the water column, radically changing the known biogeochemical cycle of antimony

Postcard: Enjoying the Comforts of Home 1852 A.D.

This black and white photographic postcard features indigenous people in front of a tent. One man lies on the ground propped up with one elbow. The man to the right of him sits and holds a pipe. Two women sit to the right of the men. Two children lie on the ground propped up on an elbow. Written text is at the top of the card. Handwriting is on the back of the card. Part of the Perils of the Plains set which are actual photos of a staged 1905 event for the NEA (National Editorial Association). The event took place on the Miller Brothers 101 Ranch near Bliss, Oklahoma.https://scholars.fhsu.edu/tj_postcards/2221/thumbnail.jp

Inorganic Concentrations in the Wood of Eastern Redcedar Grown on Different Sites

Samples of eastern redcedar (Juniperus virginiana L.) growing on soils derived from five parent materials—rhyolite, dolomite, limestone, sandstone, and chert—were analyzed for levels of inorganics in sapwood and heartwood. Eighteen elements were detected in sapwood using inductively coupled plasma optical emission spectroscopy. Neutron activation analysis was also used to determine concentrations of an additional six elements in heartwood. No difference was found between results obtained by the two analytical methods. Conventional wet chemistry techniques were used to determine nitrogen and sulfur concentrations in some samples

Freezing of Water in Hardboard: Absence of Changes in Mechanical Properties

One-eighth-inch dry process and two species mixes of 7/16 in. wet process hardboard roofings plus 1/8 in. dry process and 7/16 in. wet process standard hardboards were examined using differential thermal analysis to ascertain the maximum moisture content that exterior hardboard could attain without exhibiting significant freezing. All samples with moisture contents greater than ≈20% exhibited high temperature freezing near - 10 C. Additionally, dry process materials with moisture contents near or above 30% had a distinct low temperature freezing event near -35 C. Integration of the area under the freezing curves indicated that ≈ 3% of the water contained in these samples froze at low temperature. During thawing, this fraction of water melted above -10 C. This type of thermal hysteresis is characteristic of the freeze/thaw behavior expected for supercooled water. Mechanical strength tests performed on dry process (4.1 and 41.1% moisture content) and wet process (4.4 and 34.3% moisture content) standard hardboard exposed to freeze/thaw cycling to -50 C revealed no consistent changes in the modulus of elasticity, modulus of rupture, tensile strength parallel to surface, or internal bond strength