Minimum continental velocities with respect to the pole since the Archean     

Laura Ullrich  Rob Van Der Voo 《Tectonophysics》1981,74(1-2)

Paleomagnetic apparent polar wander paths provide a method for estimating minimum plate velocities which can be extended much further into the geologic past than can be estimated based on sea-floor magnetic anomalies. Minimum velocities can be determined from the rate of change of latitude as derived relative to a fixed pole. Such latitudinal velocities have been determined for the center of mass of the North American, Baltic, Siberian and African shields since the Archean. The results indicate that plate velocities in the past have at times easily exceeded those for present-day continents, and that they often were equivalent to present-day oceanic velocities, although there are peaks and troughs through time. North American velocities are significantly greater prior to one billion years ago than those of Siberia or Baltica.  相似文献   

Lessons from China: building technological capabilities for low carbon technology transfer and development     

Jim Watson  Rob Byrne  David Ockwell  Michele Stua 《Climatic change》2015,131(3):387-399

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Foreign policy ‘trilemmas’: understanding China's stance on international cap-and-trade     

Yitian Huang  Rob Bailis 《Climate Policy》2013,13(4):494-516

This article uses a policy analogy approach to explore China's attitude toward the possibility of global carbon market integration, including the development of a common cap-and-trade market for the global civil aviation industry. Like in other foreign policy domains, in international cap-and-trade, China faces a ‘trilemma’ between carbon market integration, state sovereignty and policy flexibility. By referring to how China has approached a comparable trilemma in foreign exchange policy making, we analyse China's possible stance on international cap-and-trade. We argue that China will prefer to gradually establish and strengthen, to a limited extent, intergovernmental governance mechanisms, which allow nation-states to prioritize sovereignty and policy flexibility in carbon trading policy making. In the conclusion we use this argument to explain China's responses to the carbon-trading initiatives of Australia, the EU, the International Civil Aviation Organization (ICAO), and the World Bank.

Policy relevance

The international community has reached a consensus on the use of market mechanisms for mitigating climate change. While opposing the EU's plan to include Chinese airlines in the EU Emissions Trading Scheme, China has started to co-explore with Australia the possibility of linking their carbon markets, and has adopted a supportive attitude toward the carbon trading initiatives led by the ICAO and the World Bank. Considering China's status as the largest emitting country of GHGs and its interdependence with major developed and developing countries, China's substantial participation would be crucial to the success of the global market-based efforts to reduce GHG emissions. This article presents an initial attempt to develop a better understanding of China's stance on international cap-and-trade.  相似文献   

Late orogenic, large-scale rotations in the Tien Shan and adjacent mobile belts in Kyrgyzstan and Kazakhstan   总被引：6，自引：1，他引：5  

Rob Van der Voo  Natalia M. Levashova  Ludmila I. Skrinnik  Taras V. Kara  Mikhail L. Bazhenov   《Tectonophysics》2006,426(3-4):335-360

Most of Kazakhstan belongs to the central part of the Eurasian Paleozoic mobile belts for which previously proposed tectonic scenarios have been rather disparate. Of particular interest is the origin of strongly curved Middle and Late Paleozoic volcanic belts of island-arc and Andean-arc affinities that dominate the structure of Kazakhstan. We undertook a paleomagnetic study of Carboniferous to Upper Permian volcanics and sediments from several localities in the Ili River basin between the Tien Shan and the Junggar–Alatau ranges in southeast Kazakhstan. Our main goal was to investigate the Permian kinematic evolution of these belts, particularly in terms of rotations about vertical axes, in the hope of deciphering the dynamics that played a role during the latest Paleozoic deformation in this area. This deformation, in turn, can then be related to the amalgamation of this area with Baltica, Siberia, and Tarim in the expanding Eurasian supercontinent. Thermal demagnetization revealed that most Permian rocks retained a pretilting and likely primary component, which is of reversed polarity at three localities and normal at the fourth. In contrast, most Carboniferous rocks are dominated by postfolding reversed overprints of probably “mid-Permian” age, whereas presumably primary components are isolated from a few sites at two localities. Mean inclinations of primary components generally agree with coeval reference values extrapolated from Baltica, whereas declinations from primary as well as secondary components are deflected counterclockwise (ccw) by up to  90°. Such ccw rotated directions have previously also been observed in other Tien Shan sampling areas and in the adjacent Tarim Block to the south. However, two other areas in Kazakhstan show clockwise (cw) rotations of Permian magnetization directions. One area is located in the Kendyktas block about 300 km to the west of the Ili River valley, and the other is found in the Chingiz Range, to the north of Lake Balkhash and about 400 km to the north of the Ili River valley. The timing of the ccw as well as cw rotations is clearly later than the disappearance of any marine basins from northern Tarim, the Tien Shan and eastern Kazakhstan, so that the rotations cannot be attributed to island-arc or Andean-margin plate settings — instead we attribute the rotations to large-scale, east–west (present-day coordinates), sinistral wrenching in an intracontinental setting, related to convergence between Siberia and Baltica, as recently proposed by Natal'in and Şengör [Natal'in, B.A., and Şengör, A.M.C., 2005. Late Palaeozoic to Triassic evolution of the Turan and Scythian platforms: the pre-history of the palaeo-Tethyan closure, Tectonophysics, 404, 175–202.]. Our previous work in the Chingiz and North Tien Shan areas on Ordovician and Silurian rocks suggested relative rotations of  180°, whereas the Permian declination differences are of the order of 90° between the two areas. Thus, we assume that about 50% of the total post-Ordovician rotations are of pre-Late Permian age, with the other half of Late Permian–earliest Mesozoic age. The pre-Late Permian rotations are likely related to oroclinal bending during plate boundary evolution in a supra-subduction setting, given the calc-alkaline character of nearly all of the pre-Late Permian volcanics in the strongly curved belts.  相似文献   

SCUBA's first-born: SMM J02399-0136     

Rob Ivison  Ian Smail  Andrew Blain  Jean-Paul Kneib  David Frayer 《Astrophysics and Space Science》1999,266(1-2):285-290

We discuss observations of the submm-selected galaxy,SMM J02399-0136, and what has been learnt about it during the yearfollowing its discovery. SMM J02399-0136 was the first distantgalaxy detected in surveys with the Submm Common-User Bolometer Array(SCUBA). Its association with a massive, gas-rich starburst/AGN atz = 2.8 has lead to suggestions that the prevalence of AGN in theearly Universe may be high (Ivison et al. 1998) and that these AGNmay account for a significant fraction of the far-IR background (e.g.Fixsen et al. 1998).  相似文献   

Anomalous archaeomagnetic directions and site formation processes at archaeological sites in Israel     

Rob Sternberg  Egon Lass  Eric Marion  Kaushik Katari  Matthew Holbrook 《Geoarchaeology》1999,14(5):415-439

As part of a program to investigate archaeomagnetic secular variation in Israel and implications for archaeomagnetic dating, we have identified “anomalous” results that have yielded information about site formation processes. Stereonets, vector demagnetization diagrams, and sample location maps are most useful in examining stability of magnetization and consistency of archaeomagnetic directions with each other and with what would be expected from normal secular variation. A collection of examples is presented, including: strong and hard remanence due to vitrification, unstable magnetization due to lightning strikes, superimposed thermal magnetizations, chemical remagnetization, magnetization of a hearth fragment before falling, magnetization of a hot brick after falling, and mechanical deformation of an archaeomagnetic feature. © 1999 John Wiley & Sons, Inc.  相似文献   

Clay minerals in the late Quaternary sediment of Tulare Lake,California: Implications for climate change,weathering, and erosion processes     

Junhua Guo  Christine Pyles  William Krugh  Rob Negrini 《国际泥沙研究》2019,34(5):432-443

The clay mineralogy of Tulare Lake sediment was examined to investigate hydroclimatic and environmental changes in the southern Sierra Nevada Mountains (SNM) since the most recent glacial maximum. Evolution of clay mineral assemblages elucidates significant changes in weathering, erosion, and hydroclimatic condition in the catchment. During the last glacial period (24.4–15.1 cal ka BP), low illite content implies less physical erosion of the granitic batholith rocks and a cold and arid environment in the southern SNM. Abrupt increases of illite content at 21.8–20.8 and 17.6 cal ka BP resulted from the glacier advances to the ablation zone and illite-rich glacier flour was transported down to the lake. The gradual increase of smectite induced by progressive depletion of illite-rich glacier flour from 17.6 cal ka BP toward the end of this period indicates climate was beginning to get warm and wet. From 11.9 to 5.3 cal ka BP, two warm and wet periods (10.7–9.4 and 8.2–5.2 cal ka BP) were characterized by high smectite/illite content ratios and low illite crystallinity values, suggesting intensive rainfall precipitation and more physical erosion in the highland and lowland catchment as well as more smectite formation in the terrace soils. Since the last glacial period, physical erosion, in comparison to the chemical weathering, was the dominant process responding to the hydroclimatic change in the Tulare Lake catchment. Moderate to weak chemical weathering was signified by the mostly low illite chemical weathering index of the core sediments. Such results suggest that vegetation cover in the southern SNM was low and limited.  相似文献   

Deterring effects of 8-45 kHz tone pulses on harbour seals (Phoca vitulina) in a large pool     

Kastelein RA  van der Heul S  Terhune JM  Verboom WC  Triesscheijn RJ 《Marine environmental research》2006,62(5):356-373

The marine aquaculture industry suffers losses due to pinniped attacks which damage net enclosures and fish stocks. Acoustic harassment devices (AHDs) emit loud sounds which are intended to deter pinnipeds from approaching aquaculture enclosures. At present, many AHDs emit sounds in the 8-20 kHz frequency range. It is not known whether sounds of higher frequencies have a deterrent effect on seals. Therefore five captive harbour seals (Phoca vitulina) were subjected to four series of tone pulses together spanning a broad frequency range (8, 16, 32 and 45 kHz). Pulse duration was 250 ms and pulse interval was 5s. Each of the four sounds was made deterrent by increasing the amplitude. The seals reacted by swimming away from the sounds. The displacement effect of each sound was judged by comparing the animals' surface positions, and number of surfacings, during ten 45 min baseline periods with ten 45 min test periods per frequency (one frequency per day in rotation, 40 sessions in total). The seals were displaced by all four frequencies throughout the 40 trial days. The seals came to the surface more often when the test tones were produced than in the baseline periods. The initial displacement distances did not change over the 40 test days. This suggests that operating AHDs for only short periods will be more effective and less likely to result in habituation by the seals than operating them continuously. The discomfort threshold sound pressure level (SPL) was established for each of the four pulse frequencies. The acoustic discomfort threshold SPL is defined as the boundary SPL between the area that the animals generally occupied during the transmission of the sounds and the area that they generally did not enter during sound transmission. The discomfort threshold SPL may depend on the context.  相似文献   

Marine geochemistry by Roy Chester. Unwin Hyman,London, 1990. No of pages: 698. Price £34.95 (paperback); £90.00 (hardback). ISBN 0 045 51109 8 (paperback); 0 045 511 08 X (hardback)     

Rob Raiswell 《Geological Journal》1993,28(1):96-97

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Introduction: Magnetism and site formation processes in archaeology—2     

Rob Sternberg 《Geoarchaeology》1999,14(5):375-375

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