The purpose of this study was to test the hypothesis that NH4+ uptake by heterotrophic bacteria in the subarctic Pacific is C limited. Addition of glucose (0.5–1.0 μM) stimulated NH4+ uptake in unfractionated water but had no effect on bacterial abundance. Glucose stimulation of NH4+ uptake was even greater in...
Broadband body waves recorded at 15 digital seismic stations worldwide are used to study the rupture process of the May 23, 1989 Macquarie Ridge earthquake. The centroidal solution (strike 211°, dip 86°, rake 180°, and depth of 10 km below the seafloor) indicates shallow rupture with pure right-lateral strike-slip motion...
Satellite-derived pigment concentrations from the west coast time series (WCTS) are averaged into monthly mean fields over the California Current system (CCS) for the period July 1979 to June 1986. Errors caused by the scattering algorithm used in the WCTS are reduced by an empirical correction function, although winter values...
Basaltic andesite inclusions and their host dacite from the Purico-Chascon complex in northern Chile are isotopically distinct. Textural characteristics of the inclusions are typical of those resulting from magma mingling. Serial sectioning across the interface of an inclusion and its host dacite, complemented by microdrill sampling and detailed microprobe work,...
To learn whether vine stems are less structurally stable than shrub stems, I studied the architecture, anatomy, and mechanics of western poison oak (Toxicodendron diversilobum), a plant that grows as a vine when provided with external support but otherwise as a shrub. I assessed the relative structural stabilities of vines...
Excised stem segments of vines had higher specific hydraulic conductivies (flow rate per pressure gradient per stem transverse area) than did trees during the dry season in a deciduous forest in Jalisco, Mexico. Vine species averaged from 2.7 to 203 x 10-3 m2 MPa-1 s-1 and tree species from 0.8...
Satellite thermal imagery and in situ biological and physical data are presented that describe the spatial variability of phytoplankton biomass and species composition in relation to the physical structure at the sea surface during persistent upwelling off northern California. Surface patterns in temperature, geostrophic velocity, chlorophyll, and particle size structure...
A temporal record of oxygen and NO3- concentrations in the bottom water of the Santa Barbara Basin indicates that outside waters spill over into the basin seasonally. It is proposed that an annual bottom-water cycle leads ultimately to varve production.
As evidence in support of a benthic mechanism for varve...
The spatial and temporal variability of nearshore sand bar morphology is quantified using a unique data set
spanning 2 years. The data consist of daily time exposure images of incident wave breaking on an open coast
sandy beach which may be used to infer bar morphology (Lippmann and Holman, 1989)....
Seasonal and diel changes in nutrient concentrations and nitrogen assimilation rates were used to assess the effects of NH4+ on NO3- assimilation. Surface-water NO3- concentrations ranged from 6 to 17 μM while NH4+ concentrations ranged from 0 to 0.4 μM. Total N assimilation ranged from 84 to 732 nM d–1...