Bivalve shellfish harvesting and consumption in New Zealand, 2011: data for exposure assessment

We provide an overview of bivalve molluscan shellfish (BMS) availability to New Zealanders. Data on commercial production (aquaculture) and harvesting, non-commercial (recreational and customary) harvesting and international trading (imports, exports) of BMS were assembled. These data were transformed to estimate the total weight (greenweight and meatweight) of each BMS species, and all BMS species, available to New Zealand domestic consumers in 2011. An estimated 68,000 tonnes greenweight, or 13,000 tonnes meatweight, of BMS were available. Mussels (mostly commercially-produced Perna canaliculus) accounted for 96% of the total available BMS by meatweight. Non-commercially harvested BMS were 1% of the total available BMS. BMS availability was estimated as 8 g/person/day for the total New Zealand population and 407 g/person/day for shellfish consumers. These estimates were comparable to published national consumption data. The results can be used as inputs to exposure assessment. Food availability is a useful estimate where consumption data are limited.     

Sporadic formation of slope streaks on Mars

Slope streaks are a form of gravity-driven mass-movements that frequently occur on Mars today. The cause of slope streak formation remains unclear; both, dry and wet processes have been suggested. Here, we observationally constrain the time of the year during which slope streaks form. Imagery from four Mars-orbiting cameras is mined to identify locations that have been imaged repeatedly, and the overlapping images are surveyed for streak activity. A search algorithm automatically finds the locations on the surface that have been imaged most often based on a graph representation. Dark slope streaks are found to form sporadically throughout the Mars year. At one study site in the Olympus Mons Aureole, observations constrain slope streak formation to at least five distinct time intervals within a single Mars year. New slope streaks form spatially isolated or in small groups within a few kilometers of one another. The observations suggest that slope streak triggering is unrelated to season and not caused by any large regional events. Most slope streaks are caused by sporadic events of small spatial extent.     

Designing science web sites

From a scientist’s viewpoint a web site is one tool used to conduct research. From an artist’s viewpoint web sites are a form of visual composition. From a developer’s point of view a web site is a type of application. While web sites are a relatively new medium with a particular set of constraints, they do adhere to the same basic design principles that apply to other art forms. These design principles are the basic assumptions that affect the arrangement of elements within a composition. A successful design uses the principles and elements to achieve a visual goal in the composition. A web site designed for scientists has unique properties which are not shared by many other types of web sites. These properties influence the overall visual design of the web sites. Recently at the Institute of Geophysics and Planetary Physics at UCLA undertook a re-design of a number of its websites. In the effort, the use of visual design principles combined with the properties of a science web site were put to the test. In all, six different web sites were designed each with a difference science focus. We describe the process used to design the web sites which involve forming teams of designers, scientists and developers. We present example pages from each design and conclude with a discussion of what was learned during the process.     

A late Cenozoic Earth's crust and climate dynamics record from Lake Baikal

The sedimentary record from Lake Baikal (Siberia, Russia) has been an important source of information about paleoclimatic variability in the northern hemisphere and dynamics of continental rift development. A lack of reliable chronology has, however, been a major obstacle to fully utilizing the Baikal archive for time scales beyond about 4-5 Myr. In this paper we use the distribution of ¹⁰Be to establish a new chronology for the longest core drilled in Lake Baikal so far. The ¹⁰Be-based chronology spans the last 8 Myr and provides better constraints on sedimentation rates and consequently on an east-west tectonic extension in the lake, which has been apparently coeval with other rifts in Asia that are related to the Tibetan plateau uplift. Our data also show higher ¹⁰Be flux in the sediment section older then 5 Myr compared with the younger period. This can be explained partly by warm and humid climatic conditions of the Miocene and partly by a high cosmic ray flux to the Earth resulting from possible low geomagnetic field intensity during that time.     

The magnetic fabric of some Irish Granites

Magnetic anisotropy measurements have been made on fifty-four oriented samples from the Carna and Screeb areas of the Galway Granite, and from the Ardara pluton and the Main Granite (including the Trawenagh Bay Granite) in Donegal. The origin of magnetic anisotropy in plutonic magnetic rocks is discussed, and it is concluded that it is probably due to grain alignment of inequant magnetite, which may occur either as free grains or as secondary inclusions in ferromagnesian minerals. The grain alignment may occur either whilst the magma is essentially fluid, giving a magnetic lineation transverse to the flow, or at a much later stage of consolidation during plastic deformation, in which case the magnetic lineation parallels the direction of greatest elongation. The results of the measurements are consistent with macroscopic foliations and lineations where these have been observed, but also indicate the existence of fabrics too weak to observe by conventional methods. This is because the magnetic method assesses the alignment of a very large number of grains, and is therefore much more sensitive than conventional fabric analysis. The weak fabrics can be qualitatively explained in terms consistent with other evidence relating to the emplacement of the granites, and experimental work now in progress may make possible a more quantitative interpretation.     

全球定位系统测量与青藏高原东部流变构造

通过1991～1997年期间高精度全球定位系统测量,建立了青藏高原东部及其邻区的现代地壳运动速度场。相对成都,鲜水河-小江断裂以西的藏东-滇中地区的运动速度变动在1．57～17．49mm／a之间,总体为8mm／a以上。该断裂以东地区的运动速度小,约为0～7mm／a。在此基础上,通过对围绕东喜马拉雅构造结的涡旋和川西地区的涡旋的认定,以及它们在地壳变形中的作用的分析,阐述了青藏高原东部及其邻区深部物质流变的主要形式和地壳流变构造。     

The Potential Response of Terrestrial Carbon Storage to Changes in Climate and Atmospheric CO2

We use a georeferenced model of ecosystem carbon dynamics to explore the sensitivity of global terrestrial carbon storage to changes in atmospheric CO₂ and climate. We model changes in ecosystem carbon density, but we do not model shifts in vegetation type. A model of annual NPP is coupled with a model of carbon allocation in vegetation and a model of decomposition and soil carbon dynamics. NPP is a function of climate and atmospheric CO₂ concentration. The CO₂ response is derived from a biochemical model of photosynthesis. With no change in climate, a doubling of atmospheric CO₂ from 280 ppm to 560 ppm enhances equilibrium global NPP by 16.9%; equilibrium global terrestrial ecosystem carbon (TEC) increases by 14.9%. Simulations with no change in atmospheric CO₂ concentration but changes in climate from five atmospheric general circulation models yield increases in global NPP of 10.0–14.8%. The changes in NPP are very nearly balanced by changes in decomposition, and the resulting changes in TEC range from an increase of 1.1% to a decrease of 1.1%. These results are similar to those from analyses using bioclimatic biome models that simulate shifts in ecosystem distribution but do not model changes in carbon density within vegetation types. With changes in both climate and a doubling of atmospheric CO₂, our model generates increases in NPP of 30.2–36.5%. The increases in NPP and litter inputs to the soil more than compensate for any climate stimulation of decomposition and lead to increases in global TEC of 15.4–18.2%.     

Effect of remote forcings on the winter precipitation of central southwest Asia part 1: observations

Summary We investigate the effects of the North Atlantic Oscillation (NAO) and the El Nino Southern Oscillation (ENSO) on winter precipitation in Central Southwest Asia (CSWA) using an analysis of available observed climate data. The analysis is based on correlations, composites and Singular Value Decomposition (SVD) performed using the gridded dataset of the Climatic Research Unit (CRU) and station data for the region. We find that both the NAO and ENSO affect climate over the region. In particular a positive precipitation anomaly is typically found in correspondence of the positive NAO phase and warm ENSO phase over a sub-region encompassing northern Pakistan, Afghanistan, Tajikistan and southern Uzbekistan. This conclusion is supported by a consistency across the different analysis methods and observation datasets employed in our study. A physical mechanism for such effect is proposed, by which western disturbances are intensified over the region as they encounter a low pressure trough, which is a dominant feature during positive NAO and warm ENSO conditions. Our results give encouraging indications towards the development of statistically-based prediction tools for winter precipitation over the CSWA region.     

Depositional history of organic contaminants in Narragansett Bay, Rhode Island, USA

Sediment cores were taken at three locations in Narragansett Bay, Rhode Island, USA in 1997 and analyzed for a variety of organic contaminants including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), chlordanes, linear alkyl benzenes (LABs), benzotriazoles (BZTs) and dichlorodiphenyltrichloroethanes (DDTs) and metabolites. The distributions of these chemicals at Apponaug Cove and in the Seekonk River indicate that there was a disturbance in the depositional environment relative to cores collected at these locations in 1986 demonstrating the potential for buried contaminants to be remobilized in the environment even after a period of burial. Sharp breaks in the concentration of several organic markers with known dates of introduction were successfully used to determine the sedimentation rate at Quonset Point. Both the Quonset Point and Seekonk River cores had subsurface maximums for DDTs, PCBs, PAHs and BZTs, which are consistent with expected inputs to the environment. The Apponaug Cove core showed an increase of most contaminants at the surface indicating a recent event in which more contaminated sediments were deposited at that location.