Private rights,public benefits: Industry-driven seabed protection

New Zealand has a large exclusive economic zone (EEZ) that contains a variety of marine habitats and commercially-important species. The commercial fishing industry operating within New Zealand's EEZ is of significant value to the economy and fisheries resources are managed through the extensive use of Individual Transferable Quotas (ITQs). One of the benefits of ITQs has been to better align some of the private incentives of quota owners with the public interest. These incentives contributed to an initiative proposed by the fishing industry to close large areas of New Zealand's EEZ to protect the seabed from trawling. These closed areas are termed benthic protection areas (BPAs) and protect the benthic biodiversity of about 1.1 million square kilometres of seabed—approximately 30% of New Zealand's EEZ. A significant proportion of New Zealand's known seamounts and active hydrothermal vents are protected by these closed areas. We describe and discuss the criteria used to select BPAs and some of the criticism of this marine protection initiative. We argue that the assignment of strong property rights in fishing resources was an important precondition to an industry initiative that has a significant public benefit. Where private and public interests are well aligned, government can adopt an enabling and facilitation role, ceding direct control of processes in order to get the results the align with the public interest.     

On the possible origin of troilite‐metal nodules in the Katol chondrite (L6‐7)

Microtextural study of a single troilite‐metal nodule (TMN) from the Katol L6‐7 chondrite, a recent fall (May, 2012) in India suggests that the TMN is primarily an aggregate of submicron‐scale intergrowth of troilite and kamacite (mean Ni: 6.18 wt%) juxtaposed with intensely fractured silicates, mainly olivine (Fa: 25 mole%), low‐Ca pyroxene (Fs: 21.2 mole%), and a large volume of maskelynite. Evidence of shock textures in the TMN indicates a high degree of shock metamorphism that involves plagioclase‐maskelynite and olivine‐wadsleyite/ringwoodite transformations and formation of quenched metal‐sulfide melt textures due to localized shear‐induced frictional melting. It is inferred that the TMN formation is an independent, localized event by a high energy impact and its subsequent incorporation in the ejected chondritic fragment of the parent body. Katol chondrite has been calibrated with a peak shock pressure of S5 (~45 GPa) after Stöffler et al. (1991), whereas peak shock pressure within the TMN exceeds the shock facies S6 (>45 GPa) following Bennett and McSween (1996) and Stöffler et al. (1991). Overall, the shock‐thermal history of the Katol TMN is dissimilar as compared to the host chondrite.     

New insights on petrography and geochemistry of impactites from the Lonar crater,India

The Lonar impact crater, India, is one of the few known terrestrial impact craters excavated in continental basaltic target rocks (Deccan Traps, ~65 Ma). The impactites reported from the crater to date mainly include centimeter‐ to decimeter‐sized impact‐melt bombs, and aerodynamically shaped millimeter‐ and submillimeter‐sized impact spherules. They occur in situ within the ejecta around the crater rim and show schlieren structure. In contrast, non–in situ glassy objects, loosely strewn around the crater lake and in the ejecta around the crater rim do not show any schlieren structure. These non–in situ fragments appear to be similar to ancient bricks from the Daityasudan temple in the Lonar village. Synthesis of existing and new major and trace element data on the Lonar impact spherules show that (1) the target Lonar basalts incorporated into the spherules had undergone minimal preimpact alteration. Also, the paleosol layer as preserved between the top‐most target basalt flow and the ejecta blanket, even after the impact, was not a source component for the Lonar impactites, (2) the Archean basement below the Deccan traps were unlikely to have contributed material to the impactite parental melts, and (3) the impactor asteroid components (Cr, Co, Ni) were concentrated only within the submillimeter‐sized spherules. Two component mixing calculations using major oxides and Cr, Co, and Ni suggest that the Lonar impactor was a EH‐type chondrite with the submillimeter‐sized spherules containing ~6 wt% impactor components.     

Late Pleistocene to Holocene sedimentation and hydrocarbon seeps on the continental shelf of a steep,tectonically active margin,southern California,USA

Small, steep, uplifting coastal watersheds are prolific sediment producers that contribute significantly to the global marine sediment budget. This study illustrates how sedimentation evolves in one such system where the continental shelf is largely sediment-starved, with most terrestrial sediment bypassing the shelf in favor of deposition in deeper basins. The Santa Barbara–Ventura coast of southern California, USA, is considered a classic area for the study of active tectonics and of Tertiary and Quaternary climatic evolution, interpretations of which depend upon an understanding of sedimentation patterns. High-resolution seismic-reflection data over >570 km² of this shelf show that sediment production is concentrated in a few drainage basins, with the Ventura and Santa Clara River deltas containing most of the upper Pleistocene to Holocene sediment on the shelf. Away from those deltas, the major factor controlling shelf sedimentation is the interaction of wave energy with coastline geometry. Depocenters containing sediment 5–20 m thick exist opposite broad coastal embayments, whereas relict material (bedrock below a regional unconformity) is exposed at the sea floor in areas of the shelf opposite coastal headlands. Locally, natural hydrocarbon seeps interact with sediment deposition either to produce elevated tar-and-sediment mounds or as gas plumes that hinder sediment settling. As much as 80% of fluvial sediment delivered by the Ventura and Santa Clara Rivers is transported off the shelf (some into the Santa Barbara Basin and some into the Santa Monica Basin via Hueneme Canyon), leaving a shelf with relatively little recent sediment accumulation. Understanding factors that control large-scale sediment dispersal along a rapidly uplifting coast that produces substantial quantities of sediment has implications for interpreting the ancient stratigraphic record of active and transform continental margins, and for inferring the distribution of hydrocarbon resources in relict shelf deposits.     

On the precision and accuracy of IGS orbits

In order to explore the precision and accuracy of International GNSS Service (IGS) orbits, we difference geocentric satellite positions midway between successive daily Final orbits for the period starting 5 November 2006, when the IGS switched its method of antenna calibration, through 31 December 2007. This yields a time series of orbit repeatabilities analogous to the classical geodetic test for position determinations. If we compare our average positional discontinuities to the official IGS accuracy codes, root-sum-squared (RSS) for each pair of days, we find the discontinuities are not well correlated with the predicted performance values. If instead the IGS weighted root-mean-square (WRMS) values from the Final combination long-arc analyses are taken as the measure of IGS accuracy, we find the position differences and long-arc values are correlated, but the long-arc values are exaggerated, particularly around eclipses, despite the fact that our day-boundary position differences apply to a single epoch each day and the long-arc analyses consider variations over a week. Our method is not well suited to probe the extent to which systematic effects dominate over random orbit errors, as indicated by satellite laser ranging residuals, but eclipsing satellites often display the most problematic behavior. A better metric than the current IGS orbit accuracy codes would probably be one based on the orbit discontinuities between successive days.     

Sensitivity of crop yields and land resource potential to climatic change in Ontario,Canada

Increasing concentrations of atmospheric CO₂ and other greenhouse gases are expected to contribute to a global warming. This paper examines the potential implications of a climatic change corresponding to a doubling of atmospheric concentrations of CO₂ on crop production opportunities throughout Ontario, a major food producing region in Canada. The climate is projected to become warmer and drier, but the extent of these shifts are expected to vary from region to region within Ontario. The effect of this altered climate on crop yields and the area of land capable of supporting specific crops varies according to region, soil quality and crop type. Most notable are the enhanced opportunities for grains and oilseeds in the northern regions, and the diminished production prospects for most crops in the most southerly parts of Ontario.     

Summary of the fossil record of pinnipeds of Japan, and comparisons with that from the eastern North Pacific

Abstract The fossil pinniped record of the North Pacific Ocean includes both Phocidae and Otariidae ( sensu lato ), extends from the Late Oligocene to the Late Pleistocene, is taxonomically diverse, and is constantly becoming more complete owing to additional important discoveries. The earliest and most diverse fossil pinnipeds in the North Pacific are otariids, the phocids not appearing until the latest Pliocene. The theoretical center of otariid pinniped evolutionary history has been considered by some to be in the eastern North Pacific. New materials from the western North Pacific, however, including representatives of the subfamilies Enaliarctinae, Imagotariinae, Odobeninae and Otariinae, indicate that pinniped evolutionary patterns were basin-wide phenomena, and that a more complete record undoubtedly would reveal numerous trans-Pacific distributions. This would be expected considering the distributions of living species. The paucity of fossil Phocidae and their absence from pre-Pliocene deposits are consistent with theories that the family primarily evolved outside the North Pacific.     

Short communication block lanczos method for dynamic analysis of structures

The simple Lanczos method presented in a recent paper by the writers, with application to single vector loads, is extended to include a more general dynamic loading represented as a linear combination of k vectors (load patterns). The result is a set of orthogonal vectors that is used to transform the equations of motion to a banded form, the half-bandwidth of which becomes k + 1. When k is small relative to the number of equations, this approach provides for a very efficient time-stepping solution.     

Tank damage during the may 1983 coalinga earthquake

The magnitude M = 6-5 Coalinga earthquake of 2 May 1983 caused intense ground shaking throughout the epicentral region. Unanchored cylindrical ground supported tanks located at six sites within this oil producing area were damaged; damages included elephant's foot buckling at the base of three moderate sized tanks, joint rupture and top shell buckling in one large old rivetted tank, bottom plate rupture of a relatively new welded tank and damage to the floating roofs of 11 tanks. Also oil spilled over the top of many tanks and secondary damages occurred in pipe connections, ladders, etc. In this paper an estimate is made of the intensity of ground motion at each of the tank sites, based on strong motion records made during the main shock and the strongest aftershock. Then response parameters specified by current codes are correlated with the damages observed at each tank site. Based on this comparison, it is concluded that current U.S. practice under-estimates the sloshing response of tanks with floating roofs and does not adequately address the uplifting mechanism of unanchored ground supported tanks.