Need and opportunity for a North American caribou knowledge cooperative

The importance of migratory caribou ( Rangifer tarandus ) to northerners, the increasing pressure to extract non-living resources, and predicted global climate change have led researchers, managers and resource users alike to focus on how to improve our knowledge of this unique northern ungulate. Unprecedented threats to caribou sustainability, along with the increasingly acknowledged value of indigenous hunters'contribution to caribou research, pose the additional challenge to innovate research methods that accommodate differing cultural perspectives and facilitate communication among groups. This paper surveys the state of scientific knowledge of the eleven major northern mainland herds of North America. We recommend an approach to improve our working knowledge of barren-ground caribou in order to assess better future impacts. The transfer of knowledge gained from years of research and indigenous experience on many aspects of caribou ecology should be evaluated and, where applicable, transferred to herds with more modest databases. The establishment of a North American Caribou Monitoring and Assessment System, based on a synthesis of local knowledge and research-based science, is recommended as a tool for improved communication and collective learning.     

The influence of environmental cues on the activity of silver eels (Anguilla dieffenbachii) in Lake Manapouri,New Zealand

Lake Manapouri in the South Island of New Zealand has a significant hydroelectric generation facility, which potentially has a negative impact on the successful emigration of longfin eels (Anguilla dieffenbachii) from the upper Waiau catchment. Consequently, a trap-and-transfer programme has been implemented to allow silver (migratory) eels access to the sea. The present study analysed data on the timing of captures and numbers of silver eels over four seasons, including the influence of possible migration cues. Silver eels were captured over an extended season of seven months (November–May), with peak numbers during December and January. Flow at the lake outflow was found to have a weak relationship with the number of eels caught, as did lake level, but moon phase and rainfall had no significant effect. These results highlight the variability in silver longfin eel behaviour both in terms of timing and response to potential environmental cues.     

Effects of sediment deposition on the New Zealand cockle,Austrovenus stutchburyi

New Zealand estuaries and harbours are subjected to increasing sediment deposition that can smother and bury infaunal communities, yet how coastal species respond to sediment deposition is not well understood. Here, we experimentally examined the effects of native marine sediment deposition on the NZ cockle (Austrovenus stutchburyi). Cockles were found to be highly mobile and capable burrowers, able to resurface within days from beneath 2–25?cm of sediment where no physical disturbance to their natural orientation occurred. Cockles were also resilient to daily (2?cm) reburials. However, following disturbance to their natural orientation, inverted cockles were significantly impeded when buried under 5–10?cm of sediment, with fewer adults resurfacing than sub-adults. Cockle populations are likely to be resilient to native sediment deposition, unless physically disturbed. When disturbed from their natural orientation in the sediment, higher mortality of larger adult-sized cockles would be predicted, with mortality increasing under thicker sediment deposits.     

远震体波有限破裂过程反演敏感性测试及其在汶川地震上的应用

本文利用远震P和SH波反演得到2008年5月12日汶川大地震(M_W=7.9)的一系列有限破裂模型。使用一种基于小波变换的模拟退火非线性反演方法, 我们将主断层划分成若干个子断层, 在反演时同时确定每个子断层上的滑移量、 滑动角、 上升时间(rise time)以及平均破裂速度。我们首先根据一个假定的破裂模型生成理论地震图, 将该理论地震数据作为输入进行反演, 对该有限破裂反演方法进行了一系列测试, 以验证反演对断层倾角、 平均破裂速度、 最大破裂深度等参数的敏感性。然后我们采用4个不同倾角的断层面来对汶川地震远震体波记录进行反演。结果表明, 若对只在一个断层面上模拟该地震, 30°倾角是个较为合适的值。反演的结果还表明, 此次地震有两个主要的能量释放区域, 并且主断层面存在倾角变化的可能性。在将来的研究中, 可以结合GPS, InSAR测地学以及强震等数据, 来对强震的破裂过程做更细致的研究。     

A potential stratotype for the regional lowermost stage of the continental Paleocene in China

Phanerozoic chronostratigraphic units can only be defined through their lower boundary stratotypes.The lowermost stage of the Paleocene of China,which mainly consists of terrestrial deposits,can only be defined through its lower boundary stratotype,i.e.the continental Cretaceous/Paleogene boundary stratotype.There is no section yet found which contains continuous terrestrial deposits and biostratigraphic records of the Cretaceous-Paleogene transition in Nanxiong,Guangdong and Jiayin,Heilongjiang,there is no evidence for establishing the continental stratotype of the Cretaceous/Paleogene boundary in either area.Therefore,both the"Shanghuan stage"and"Furaoan stage"are not good candidates for the lowermost stage of the Paleocene of China.From the viewpoint of charophytes,the outcrop section of the Dangyang,Hubei Province(Central China)contains the most continuous,abundant and diverse terrestrial biostratigraphic records of the Cretaceous-Paleogene transition,in particular the early Paleocene,known so far in the world.The biostratigraphic records of ostracods in the transition are also continuous,rich,and diverse.The Dangyang outcrop section is the only section known so far in China that is a possible candidate for a continental stratotype of the Cretaceous/Paleogene boundary in China and the section is the only potential section identified to date for establishing the regional lowermost stage of the Paleocene,Paleogene and Cenozoic in China or stratotype section for the stage.     

Vesiculation of high fountaining Hawaiian eruptions: episodes 15 and 16 of 1959 Kīlauea Iki

The 1959 summit eruption of Kīlauea volcano produced the highest recorded Hawaiian fountain in Hawai‘i. Quantitative analysis of closely spaced samples from the final two high-fountaining episodes of the eruption result in a fine-scale textural study of pyroclasts and provide a record of postfragmentation processes. As clast vesicularity increases, the vesicle number density decreases and vesicle morphology shifts from small and round to larger and more irregular. The shift in microtexture corresponds to greater degrees of postfragmentation expansion of clasts with higher vesicularity. We suggest the range of clast morphologies in the deposit is related to thermal zonation within a Hawaiian fountain where the highest vesicularity clasts traveled in the center and lowest traveled along the margins. Vesicle number densities are greatest in the highest fountaining episode and therefore scale with intensity of activity. Major element chemical analyses and fasciculate crystal textures indicate microlite-rich zones within individual clasts are portions of recycled lava lake material that were incorporated into newly vesiculating primary melt.     

Temperature‐Activated Auto‐Decomposition Reactions: An Under‐Utilized In Situ Remediation Solution

The remediation industry has witnessed multiple innovations arising from a greater understanding of the physical, chemical, and biological processes that control the fate and transport of chemicals in the subsurface environment. In addition, increasing emphasis is being placed on remediation solutions that are greener, simpler, and more resource efficient. The positive impacts that can be derived from this emphasis include reduced energy consumption, reduced waste emissions, and lower costs. Temperature‐activated auto‐decomposition reactions represent a potentially underutilized option for the in situ remediation of certain organic contaminants, and an option that can be both highly effective and greener than other available technologies.     

Aluminum-dependent trace element partitioning in clinopyroxene

As technical advances have dramatically increased our ability to analyze trace elements, the need for more reliable data on the compositional dependence of trace element partitioning between minerals and melt has become increasingly important. The late-Cretaceous Carmacks Group of south central Yukon comprises a succession of primitive high-Mg ankaramitic lavas characterized by shoshonitic chemical affinities and containing large complexly zoned clinopyroxene phenocrysts. The compositional zonation of the clinopyroxene phenocrysts is characterized by relatively Fe-rich (Mg^# = Mg/(Mg + Fe) = 0.85), but mottled, cores surrounded by mantles of cyclically-zoned clinopyroxene whose Mg^# varies repeatedly between 0.9 and 0.80. These cyclically zoned clinopyroxene mantles appear to record the repeated influx and mixing of batches of primitive with more evolved magma in a deep sub-crustal (∼1.2 GPa) magma chamber(s). Laser ablation ICP-MS was used to analyze the trace element variation in these zoned clinopyroxenes. The results indicate more than a threefold variation in the absolute concentrations of Th, Zr, rare earth elements (REE), and Y within individual clinopyroxene phenocrysts, with no apparent change in the degree of REE or high field strength element (HFSE) fractionation. The variation in absolute abundances of trace elements correlates closely with the major element composition of the clinopyroxene, with the most enriched clinopyroxene having the lowest Mg^# and highest Al contents. The problem is that the amount of crystal fractionation required to explain the major element variation (∼20%) in these clinopyroxene phenocrysts cannot explain the increase in the abundance of the incompatible trace elements, which would require more than 70% crystal fractionation, if constant partition coefficients are assumed. The anomalous increase in incompatible trace elements appears to reflect an increase in their partition coefficients with increasing Al^IV in the clinopyroxene; with an increase in Al₂O₃ from 1.5 to 4.0 wt.% during ∼20% crystal fractionation over a temperature decrease of ∼100°C being associated with more that a threefold increase in the partition coefficients of Th, Zr, REE, and Y. The magnitude of these increases may indicate that the substitution of these trace elements into clinopyroxene is better modeled in some natural systems by a local charge balance model, rather than the distributed charge model that better replicates the results of annealed experiments. These findings indicate that the effect of Al on the partition coefficients of incompatible trace elements in clinopyroxene may be under appreciated in natural magmatic systems and that the application of experimentally determined clinopyroxene partition coefficients to natural systems must be done with caution.