Commercial whaling,tourism, and boycotts: An economic perspective

Commercial whaling is highly contentious, angering animal rights groups and conservation organizations, who threaten boycotts. Proponents of whaling argue that many whale stocks are plentiful enough to support sustainable harvests. In terms of economic efficiency, a nation's decision to engage in whaling depends on rents from the whaling industry, ecological and market linkages, and the potential for boycotts. We analyze the tradeoffs involved in a nation's decision to engage in whaling, whale-watching, and fishing. Scenarios exist in which whaling is economically rational. Indeed, sometimes it makes economic sense to subsidize whaling. In other circumstances, market pressures make commercial whaling inefficient.     

A Hubble Space Telescope/NICMOS view of the prototypical giant Hii region NGC604 in M33

We present the first high-spatial-resolution near-infrared (NIR) imaging of NGC604, obtained with the NICMOS camera onboard the Hubble Space Telescope (HST). These NICMOS broad-band images reveal new NIR point sources, clusters, and diffuse structures. We find an excellent spatial correlation between the 8.4 GHz radio continuum and the 2.2 μm nebular emission. Moreover, massive young stellar object candidates appear aligned with these radio peaks, reinforcing the idea that those areas are star-forming regions. Three different scaled OB associations are recognized in the NICMOS images. The brightest NIR sources in our images have properties that suggest that they are red supergiant stars, of which one was previously known. This preliminary analysis of the NICMOS images shows the complexity of the stellar content of the NGC604 nebula.     

Parent stars of extrasolar planets – VIII. Chemical abundances for 18 elements in 31 stars

We present the results of detailed spectroscopic abundance analyses for 18 elements in 31 nearby stars with planets (SWPs). The resulting abundances are combined with other similar studies of nearby SWPs and compared to a sample of nearby stars without detected planets. We find some evidence for abundance differences between these two samples for Al, Si and Ti. Some of our results are in conflict with a recent study of SWPs in the SPOCS data base. We encourage continued study of the abundance patterns of SWPs to resolve these discrepancies.     

Precision abundance analysis of bright H ii galaxies

We present high signal-to-noise ratio spectrophotometric observations of seven luminous H  ii galaxies. The observations have been made with the use of a double-arm spectrograph which provides spectra with a wide wavelength coverage, from 3400 to 10 400 Å free of second-order effects, of exactly the same region as that of a given galaxy. These observations are analysed applying a methodology designed to obtain accurate elemental abundances of oxygen, sulphur, nitrogen, neon, argon and iron in the ionized gas. Four electron temperatures and one electron density are derived from the observed forbidden line ratios using the five-level atom approximation. For our best objects, errors of 1 per cent in t _e([O  iii ]), 3 per cent in t _e([O  ii ]) and 5 per cent in t _e([S  iii ]) are achieved with a resulting accuracy of 7 per cent in total oxygen abundances, O/H.
The ionization structure of the nebulae can be mapped by the theoretical oxygen and sulphur ionic ratios, on the one side, and the corresponding observed emission line ratios, on the other – the η and η' plots. The combination of both is shown to provide a means to test photoionization model sequences presently applied to derive elemental abundances in H  ii galaxies.     

Using geomagnetic indices to forecast the next sunspot maximum

The Babcock solar dynamo model and known interactions of the interplanetary magnetic field with the earth's magnetosphere are used to explain the relations found between geomagnetic indices at solar minimum and the sunspot number at the following solar maximum. We augment the work of Kane (1987) by updating his method of analysis, including recent smoothed aa and A_P indices. We predict a smoothed maximum sunspot number of 163±40 to peak in October 1990±9 months for solar cycle 22. This value is close to the Schatten and Sofia (1987) predicted value of 170±25, using more direct solar indicators.Now at Dept. of Astronomy, Univ. of Washington     

The 322 ka Tiribí Tuff: stratigraphy, geochronology and mechanisms of deposition of the largest and most recent ignimbrite in the Valle Central, Costa Rica

The Tiribí Tuff covered much of the Valle Central of Costa Rica, currently the most densely populated area in the country (∼2.4 million inhabitants). Underlying the tuff, there is a related well-sorted pumice deposit, the Tibás Pumice Layer. Based on macroscopic characteristics of the rocks, we distinguish two main facies in the Tiribí Tuff in correlation to the differences in welding, devitrification, grain size, and abundance of pumice and lithic fragments. The Valle Central facies consists of an ignimbritic plateau of non-welded to welded deposits within the Valle Central basin and the Orotina facies is a gray to light-bluish gray, densely to partially welded rock, with yellowish and black pumice fragments cropping out mainly at the Grande de Tárcoles River Gorge and Orotina plain. This high-aspect ratio ignimbrite (1:920 or 1.1×10⁻³) covered an area of at least 820 km² with a long runout of 80 km and a minimum volume outflow of 25 km³ (15 km³ DRE). Geochemically, the tuff shows a wide range of compositions from basaltic-andesites to rhyolites, but trachyandesites are predominant. Replicate new ⁴⁰Ar/³⁹Ar age determinations indicate that widespread exposures of this tuff represent a single ignimbrite that was erupted 322±2 ka. The inferred source is the Barva Caldera, as interpreted from isopach and isopleth maps, contours of the ignimbrite top and geochemical correlation (∼10 km in diameter). The Tiribí Tuff caldera-forming eruption is interpreted as having evolved from a plinian eruption, during which the widespread basal pumice fall was deposited, followed by fountaining pyroclastic flows. In the SW part of the Valle Central, the ignimbrite flowed into a narrow canyon, which might have acted as a pseudo-barrier, reflecting the flow back towards the source and thus thickening the deposits that were filling the Valle Central depression. The variable welding patterns are interpreted to be a result of the lithostatic load and the influence of the content and size of lithic fragments.     

The Ba/Ca record of corals from the Southern Gulf of Mexico: Contributions from land-use changes, fluvial discharge and oil-drilling muds

The Ba/Ca in the growth bands of Montastraea faveolata from the Veracruz Reef System was used to reconstruct the long-term environmental change associated to anthropogenic activity in the Southern Gulf of Mexico (SGM). The 168-yr coral record shows two periods of distinct Ba concentrations: a pre-industrial period (1835-1965: 7.54 μmol/mol) followed by an industrial one (1966-2000: 8.57 μmol/mol). As human population quadrupoled during the latter, sediment load in the fluvial discharge also increased due to changes in land-use, yielding a 14% increase in the Ba-levels. A remarkable finding is that the periods at which the coral Ba/Ca ratio losses its correlation with fluvial discharge coincide exactly with peak periods of high barite consumption (used for oil drilling) in the Northern Gulf of Mexico, and the onset of oil drilling in the SGM. This finding suggests that barite may be one of the dominant sources for dissolved-Ba in the SGM.     

Occurrence and distribution of polycyclic aromatic hydrocarbons in surface sediments of San Diego Bay marinas

Polycyclic aromatic hydrocarbons (PAHs) have garnered much attention due to their bioaccumulation, carcinogenic properties, and persistence in the environment. Investigation of the spatial distribution, composition, and sources of PAHs in sediments of three recreational marinas in San Diego Bay, California revealed significant differences among marinas, with concentrations in one site exceeding 16,000 ng g^? 1. ‘Hotspots’ of PAH concentration suggest an association with stormwater outfalls draining into the basins. High-molecular weight PAHs (4–6 rings) were dominant (> 86%); the average percentage of potentially carcinogenic PAHs was high in all sites (61.4–70%) but ecotoxicological risks varied among marinas. Highly toxic benzo(a)pyrene (BaP) was the main contributor (> 90%) to the total toxic equivalent quantity (TEQ) in marinas. PAHs in San Diego Bay marina sediments appear to be derived largely from pyrogenic sources, potentially from combustion products that reach the basins by aerial deposition and stormwater drainage from nearby streets and parking lots.     

Quantifying atmospheric stability conditions at a swine facility and an adjacent corn field in Iowa, USA

Atmospheric stability conditions in the atmospheric surface layer control the distance and direction of transport of air contaminants. Near confined animal facilities, transport processes significantly impact air quality as these sites typically act as point sources of dust and odor constituents; however, little information is available on atmospheric stability effects. This study was conducted to assess year-round temporal patterns of atmospheric stability at a swine production facility and an adjacent commercial corn field (CF) in the US Midwest. Two towers of 10 and 20?m heights for continuous micrometeorological measurements were deployed within a CF and between swine buildings (BSB), respectively. Each tower was equipped with an eddy-covariance system at 6.8?m height, infrared thermometers, and six cup anemometers with thermocouples installed at log-distributed heights. Overall results from gradient Richardson number and Monin?CObukhov (z/L) calculations revealed a greater prevalence of unstable conditions for BSB compared with CF. During the 13-month measurement period, unstable cases (z/L ranging from ?1 to ?0.01) occurred 1.4 times more frequently for BSB than CF (52 vs. 39%, respectively), while stable cases (0.011?C0.2) were 1.8 times more frequent for CF than BSB (24 vs. 14%, respectively). These patterns were partly associated with higher surface radiometric temperatures for BSB. Relatively greater diurnal heat capture at BSB (ground and roof surfaces) and a cooling effect in CF through active canopy transpiration during the daytime explain these z/L and radiometric temperature results. Prevalent diurnal atmospheric instability at BSB suggests enhanced ascendant vertical transport of air pollutants perhaps causing greater mixing/dilution with the atmospheric layer and/or their facilitated transport over greater distances when sorbed onto particles. This enhanced understanding of the spatio-temporal patterns of atmospheric stability can be subsequently applied in further studies for identifying effective odor mitigation strategies near commercial animal production facilities.     

Diffuse Emission of Hydrogen from Poás Volcano,Costa Rica,America Central

We report the results of four soil H₂ surveys carried out in 2000–2003 at Poás volcano, Costa Rica, to investigate the soil H₂ distribution and evaluate the diffuse H₂ emission as a potential surveillance tool for Poás volcano. Soil gas H₂ contents showed a wide range of concentration from 0.2 to 7,059 ppmV during the four surveys. Maps of soil gas H₂ based on Sequential Gaussian Simulation showed low H₂ concentration values in the soil atmosphere (<0.7 ppmV) for most of the study area, whereas high soil gas H₂ values were observed inside the active crater of Poás. A significant increase in soil gas H₂ concentration was observed inside the active crater during 2001 and 2002 with respect to year 2000, followed by a decrease in 2003. The observed spatial and temporal variations of soil H₂ concentration have been well correlated with seismicity, microgravimetry and fumarolic chemistry changes which occurred during this study. These observations evidence changes in the shallow magmatic-hydrothermal system of Poás, and it might be related to a potential magmatic intrusion during the period 1998–2004. Therefore, monitoring diffuse H₂ emission of Poás has become an important geochemical tool for the monitoring of its volcanic activity.