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731.
Clare M. Robertson Martin S. Brook Kat A. Holt Ian C. Fuller Douglas I. Benn 《New Zealand geographer》2013,69(1):14-25
Hooker Glacier in the central Southern Alps of New Zealand has undergone significant downwasting and recession (~2.14 km) during the last two centuries. High retreat rates (51 m a?1 1986–2001, 43 m a?1 2001–2011) have produced a large (1.22 km2) proglacial lake. We present a retreat scenario for Hooker Glacier. A retreat scenario predicts that the glacier terminus will stabilise >3 km up‐valley of the current lake outlet after 2028 when ice velocity equals calving rate. 相似文献
732.
Colette C.A. Starheim Christopher Gomez Justin Harrison Claire Kain Nicholas J. Brewer Kirsty Owen Danang Sri Hadmoko Heather Purdie Peyman Zawar‐Reza Ian Owens Patrick Wassmer Franck Lavigne 《New Zealand geographer》2013,69(1):26-38
Previous research on debris‐flow deposit structure typically reports little to no visually discernible stratigraphy. The preliminary findings presented here provide evidence for more complex internal deposit architecture with inverse grading and subunits thought to reflect individual flow surges. Ground‐penetrating radar surveys, geospatial data and field observations are used to describe 10 subunits traceable over the 14 lateral radargrams imaging the lower 38 m of the deposit. Additional subunits are depicted further upslope in a longitudinal transect. As well as demonstrating the need for continued investigation of deposit architecture using non‐traditional techniques, these results may help improve future interpretations of post‐event deposits. 相似文献
733.
Grant Ian Thrall 《The Professional geographer》2013,65(3):446-447
This study seeks to examine the relationship between childhood exposure to air pollution and long-term respiratory health and to identify significant predictors of respiratory health in adulthood. Logistic regression modeling was undertaken using health and exposure data for 395 participants who resided during childhood in four distinct neighborhoods in Hamilton, Ontario, Canada. Significant predictors include exposure to SO2 in childhood, location of residence in childhood, sex, residential and occupational histories, stressful life events, and respiratory health in childhood. This study suggests that the health impacts of childhood exposure to air pollution are located beyond the short-term period that most research addresses. 相似文献
734.
牙形石SHRIMP微区原位氧同位素分析方法 总被引:7,自引:0,他引:7
氧同位素温度计已被用于古温度变化研究多年。生物化石磷酸盐中的氧同位素组成对古气候环境变化响应灵敏,牙形石在古生代到中生代的古海洋地层中广泛存在,并具有较为重要的地层学意义,是研究古温度变化的最佳样品之一。SHRIMP具备高分辨、高灵敏、高精度和微量及原位微区分析的特点,可以进行20μm范围内的原位(in-situ)同位素分析。本文介绍了作者利用SHRIMP IIe-MC建立的牙形石微区原位氧同位素分析方法,这是国内关于该方法的首次报导。本文对磷灰石标准样Durango进行了测定,连续七昼夜获得的253次测定结果,平均值为δ18 Oapatite=9.78‰±0.29‰,与该标准参考值δ18 Oapatite=9.81‰±0.25‰(Williams,未刊资料)一致。作者并以二叠系—三叠系界线上下海水温度变化研究为示范,对采自西藏文布当桑二叠系—三叠系剖面上的49个层位中的237件牙形石样品进行了914个氧同位素分析,为研究二叠系—三叠系界线上发生的生物灭绝事件前后的海水温度变化提供了可靠详实的数据。 相似文献
735.
736.
Neoliberalisation,rural land trusts and institutional blending 总被引:1,自引:0,他引:1
In the context of rural land conservation, neoliberalisation involves an increasingly wide range of changes in formal and informal institutional arrangements. These affect the relationship between the state and the market in a variety of ways and have different implications for the governance of rural land. In the context of rural land conservation in the UK, we identify a broad range of changes to policy that promote altered ownership and market related institutional forms, all of which might be seen as forms of neoliberalisation. In some instances these promote market forces and private ownership, while in others they push back the market and support collectivisation. We argue that the complex processes of the decomposition property and reassignment of property rights and the emergence of new forms of governance and partnership are better characterised in terms of institutional blending. 相似文献
737.
Simon A. Hunt Alex Lindsay-Scott Ian G. Wood Michael W. Ammann Takashi Taniguchi 《Physics and Chemistry of Minerals》2013,40(1):73-80
Orthorhombic post-perovskite CaPtO3 is isostructural with post-perovskite MgSiO3, a deep-Earth phase stable only above 100 GPa. Energy-dispersive X-ray diffraction data (to 9.4 GPa and 1,024 K) for CaPtO3 have been combined with published isothermal and isobaric measurements to determine its P–V–T equation of state (EoS). A third-order Birch–Murnaghan EoS was used, with the volumetric thermal expansion coefficient (at atmospheric pressure) represented by α(T) = α0 + α1(T). The fitted parameters had values: isothermal incompressibility, $ K_{{T_{0} }} $ = 168.4(3) GPa; $ K_{{T_{0} }}^{\prime } $ = 4.48(3) (both at 298 K); $ \partial K_{{T_{0} }} /\partial T $ = ?0.032(3) GPa K?1; α0 = 2.32(2) × 10?5 K?1; α1 = 5.7(4) × 10?9 K?2. The volumetric isothermal Anderson–Grüneisen parameter, δ T , is 7.6(7) at 298 K. $ \partial K_{{T_{0} }} /\partial T $ for CaPtO3 is similar to that recently reported for CaIrO3, differing significantly from values found at high pressure for MgSiO3 post-perovskite (?0.0085(11) to ?0.024 GPa K?1). We also report axial P–V–T EoS of similar form, the first for any post-perovskite. Fitted to the cubes of the axes, these gave $ \partial K_{{aT_{0} }} /\partial T $ = ?0.038(4) GPa K?1; $ \partial K_{{bT_{0} }} /\partial T $ = ?0.021(2) GPa K?1; $ \partial K_{{cT_{0} }} /\partial T $ = ?0.026(5) GPa K?1, with δ T = 8.9(9), 7.4(7) and 4.6(9) for a, b and c, respectively. Although $ K_{{T_{0} }} $ is lowest for the b-axis, its incompressibility is the least temperature dependent. 相似文献
738.
Isotopic age determinations on granitic rocks from Tasmania 总被引:1,自引:1,他引:0
Potassium‐argon and rubidium‐strontium isotopic age measurements show that emplacement of granitic rocks in Tasmania occurred during the Late Devonian and Early Carboniferous and in pre‐Devonian times, possibly in the Cambrian. In addition, a Precambrian granite, dated at about 750 m.y., has been recognized on the west coast of King Island. The granitic bodies of pre‐Devonian age include the Murchison River Granite, the Dove River Granite and its correlatives, and the adamellite on the southwest coast of Tasmania at Elliott Bay. These rocks were deformed during the Devonian Tabberabberan Orogeny with the result that leakage of radiogenic daughter products has occurred from minerals. Hence the indicated ages are younger than the true ages. Possibly these granitic rocks were emplaced during the Jukesian Movement of the Tyennan Orogeny, in the Late Cambrian, although a Precambrian age cannot be excluded for some of the bodies. As recognized by earlier workers the most important period of emplacement of granitic rocks in Tasmania was in the Middle Palaeozoic. The measured dates for this group of rocks range from 375 to 335 m.y., and indicate that intrusion occurred over an extended period from the Late Devonian to the Early or possibly Middle Carboniferous. There are distinct concentrations of measured ages at about 370 and 340 m.y. The granitic bodies of northeast Tasmania mainly yield the older age, whereas those of northwest Tasmania give the younger age. As the granites are post‐tectonic bodies the older age of about 375 m.y. provides a younger limit to the time of completion of the main folding in the Tabberabberan Orogeny, and this is consistent with the stratigraphic evidence. The evidence suggests that generation of granitic magma was initiated during the main folding associated with the Tabberabberan Orogeny, but that emplacement of the granites into the upper crust continued over a long period subsequently to the main folding phase. Alternatively, the younger granitic bodies, dated at about 340 m.y., may indicate that these rocks are related to the Early Carboniferous Kanimblan Orogeny recognized in Victoria and New South Wales; however, there is no field evidence to support such a proposition. 相似文献
739.
During the Cainozoic there was widespread volcanism, mainly basaltic, in eastern New South Wales. Numerous new K‐Ar ages, together with previously published results, provide information on the age of virtually all the main volcanic provinces, and indicate that the volcanism started about 70 m.y. ago in the Late Cretaceous, and was continuous from about 60 m.y. ago (Palaeocene) until about 10 m.y. ago (middle Miocene). There has been no volcanic activity since 10 m.y. ago. The ages of uplift of the Eastern Highlands are estimated from the relationship of the dated basaltic flows to the topography. A major uplift is deduced some time between the mid‐Cretaceous and late Oligocene, followed by a quiescent period. A further uplift started some time after the middle Miocene, and it continues to the present day. The highland was uplifted differentially both along and transverse to the axis. 相似文献
740.