ALBERT

Description: Eddy correlation measurements over the ocean give CO2 fluxes an order of magnitude or more larger than expected from mass balance measurements using radiocarbon and radon 222. In particular, Smith and Jones (1985) reported large upward and downward fluxes in a surf zone at supersaturations of 15% and attributed them to the equilibration of bubbles at elevated pressures. They argue that even on the open ocean such bubble injection may create steady state CO2 supersaturations and that inferences of fluxes based on air-sea pCO2 differences and radon exchange velocities must be made with caution. We defend the global average CO2 exchange rate determined by three independent radioisotopic means: prebomb radiocarbon inventories; global surveys of mixed layer radon deficits; and oceanic uptake of bomb-produced radiocarbon. We argue that laboratory and lake data do not lead one to expect fluxes as large as reported from the eddy correlation technique; that the radon method of determining exchange velocities is indeed useful for estimating CO2 fluxes; that supersaturations of CO2 due to bubble injection on the open ocean are negligible; that the hypothesis that Smith and Jones advance cannot account for the fluxes that they report; and that the pCO2 values reported by Smith and Jones are likely to be systematically much too high. The CO2 fluxes for the ocean measured to date by the micrometeorological method can be reconciled with neither the observed concentrations of radioisotopes of radon and carbon in the oceans nor the tracer experiments carried out in lakes and in wind/wave tunnels.

Description: The effect of two 70 W underwater electric lamps on the catch rate of a commercial bottom otter trawl was determined by comparative trials both at night and in daylight. It was found that, although the overall numbers and weights of fish caught did not differ, most of the species which were caught in large enough numbers for a judgement to be made showed a reaction to light. Three species, Trachurus trachurus, Merlangius merlangus and Trisopterus minutus were attracted and four species, Eutriglagurnardus, Micromesistius poutassou, Merluccius merluccius and Limanda limanda were scared off by light. The possible use of lights to further the development of selective commercial bottom trawling by attracting or scaring particular species is discussed.

Description: Transects of the submersible Alvin across rock outcrops in the Oregon subduction zone have furnished information on the structural and stratigraphic framework of this accretionary complex. Communities of clams and tube worms, and authigenic carbonate mineral precipitates, are associated with venting sites of cool fluids located on a fault-bend anticline at a water depth of 2036 meters. The distribution of animals and carbonates suggests up-dip migration of fluids from both shallow and deep sources along permeable strata or fault zones within these clastic deposits. Methane is enriched in the water column over one vent site, and carbonate minerals and animal tissues are highly enriched in carbon-12. The animals use methane as an energy and food source in symbiosis with microorganisms. Oxidized methane is also the carbon source for the authigenic carbonates that cement the sediments of the accretionary complex. The animal communities and carbonates observed in the Oregon subduction zone occur in strata as old as 2.0 million years and provide criteria for identifying other localities where modern and ancient accreted deposits have vented methane, hydrocarbons, and other nutrient-bearing fluids.

Description: Temperature and sensory indices of human responsee to the thermal environment are often expressed in terms of the known in a controlled laboratory environment, as a standard. The three rational indices of this type to be considered are (1) ASHARE's Standard Effective Temperature (SET*) Index, defined as the equivalent dry bulb temperature of an isothermal environment at 50% RH in wich a subject, while wearing clothing standardized for activity concerned, would have the same heat stress (skin temperature Tsk) and thermoregulatory strain (skin wettedness, w) as in the actual test environment; (2) Fanger's Predicted Mean Vote (PMV) Index, defined in terms of the heat load that would be required to restore a state of "Comfort" and evaluated by his Comfort Equation; and (3) Winslow's Skin Wettedness Index of "Thermal Discomfort" (DISC) defined in terms of the fraction of the body surface, wet with perspiration, required to regulate body temperature by evaporative cooling. The classic difference between PMV and DISC as predictors of warm discomfort occurs at very high and very low humidity but both lead to essentially the same judgment at average humidities (40-60% RH or 1-2 kPa). A new index PMV* is proposed for any dry or humid environment by simply replacing operative temperature To in Fanger's Comfort Equation with SET*. The use of PMV* as a sensor of heat stress and strain, is illustrated for typical HVAC situations and with a new Comfort-Humidity psychometric chart for indoor environments.

Description: Squid regurgitated by Greyheaded and Yellownosed Albatrosses at the Prince Edward Islands were predominantly two onychoteuthid species, Kondakovia longimana and Moroteuthis knipovitchi. Both squid are characteristic of cold, Antarctic waters and may have been caught south of the Antarctic Convergence, some 350 km to the south of the breeding station. Both albatross species regurgitated similar squid (by species and size), and these squid were similar to those found in previous studies of the diet of Wandering, Sooty and Lightmantled Sooty Albatrosses at the Prince Edward Islands

Description: A collection of 130 specimens of Sepiola (ligulata, robusta, rondeletii, intermedia), 115 Rondeletiola minor, 90 Sepietta ( obscura, neglecta) and more abundant samples of S. oweniana obtained by trawl fishing in the Ligurian Sea are briefly illustrated in terms of depth distribution, sex ratio and maturity stages.

Description: Magnetic lineation mapping in the western central Pacific has revealed a pair of opposite-sensed, fanned lineation patterns that define the accretionary boundaries of the fossil Magellan microplate. This tectonic synthesis results from extensive magnetic mapping of two new lineation patterns over a large area and extended mapping of previously identified lineations. The entire evolutionary history of the Magellan microplate is well constrained to a 9-m.y. period in the Early Cretaceous by synchronous spreading patterns and associated geologic data. During this period the microplate grew and evolved as a generally rectangular structure to a final size of 700 km×600 km with spreading centers on two opposing sides and transform faults on the other two sides. The lifetime and size of the Magellan microplate are somewhat longer and larger, respectively, than presently active microplates on the East Pacific Rise. However, these modern structures are still evolving and growing, and the tectonic behavior of the modern and Cretaceous systems appears to be similar. Study of both active and fossilized microplates should provide additional insights on their common tectonic histories. In particular, we show that the Magellan Trough spreading center behaved as an asymmetric accretionary plate boundary that can be described with two separate poles of motion very close to this spreading center during much of its history. The Magellan Trough spreading center then failed as a result of a larger ridge reorganization at the triple junction of the Pacific, Farallon, and Phoenix plates at Ml0N time. Microplate activity ceased when the microplate became welded to the Pacific plate at M9 time.

Description: The magnetic anomaly pattern over the Red Sea can be modeled as a continuous system of sea-floor spreading from the early Miocene to the present by using a time-varying process filter. The half spreading rate is approximately 1 cm/yr (0.4 in./yr) since initial rifting. The parameters that determine the process filter and development of the transition zone are the intrusion parameter (a measure of the dispersion of feeder dikes or horizontal strain about the rift axis), a flow parameter (a measure of the average flow width), and the effusion parameter (a measure of the volcanic effusion and thickness of layer 2). Application of a time-varying process filter appears to be a powerful tool in analyzing magnetic anomalies over passive continental margins. We estimate the flow parameter to be 2.7 km (1.7 mi) and the intrusion parameter to be 7.5 km (4.7 mi) at early rifting. These values suggest that a wide distribution of axial dikes or horizontal strain is the dominant factor in forming the magnetic anomaly pattern. Reduction in the width of the intrusion parameter and the effusion rate as rifting proceeded resulted in focusing of the strain, thinning of layer 2, and formation of the Red Sea deeps. The interpretation of the anomaly pattern implies that basement within the main trough of the Red Sea is composed of a thick accumulation of volcanic sills and flows deposited during early rifting. Extrusion of the lavas occurred over a wide (up to 60 km or 37 mi) zone of strain distributed about the rift axis. The development of this thickened zone of igneous crust is the second of three successive stages of extension for the Red Sea basin. These stages are as follows. (1) An initial stage of crustal stretching or listric faulting in the Oligocene accompanied by probable regional uplift. (2) A period of high volcanic effusion accompanied by the emplacement of stratoid basalts. The stratoid volcanics form overlapping flows and sills with intercalated sediments within the main trough. The spreading center narrowed from the early Miocene to the present. (3) Steady-state sea-floor spreading from Pliocene to present south of a transitional zone near 22°S. The process filter width derived from the magnetic anomaly pattern at earliest rifting can be used to estimate the lateral variation from igneous to continental-type crust in a statistical sense. Our data suggest that the transition from 100% continental crust to 100% igneous or stratoid-type crust should occur within an interval of approximately 32 km (20 mi). Our modeling suggests that phase 2, or the stratoid phase, began about the time of anomaly 5C or chron C5C approximately 16 Ma. This age is compatible with geologic estimates of the initial rifting at the late Oligocene to early Miocene (Coleman, 1974; Gass, 1977). The opening rate for Africa-Arabia plate motion has remained relatively constant since early rifting although the African margin appears to be accreting faster than the Arabian plate.