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21.
Robert Meyer Franz May Christian Müller Kees Geel Christian Bernstone 《Environmental Geology》2008,54(8):1607-1618
This paper reports on the regional screening, selection and geological characterisation of a potential on-shore CO2 storage site (saline aquifer) in north-eastern Germany. The main objective of this study was to identify and investigate
a candidate storage site, capable to accommodate the total amount of approximately 400 million tons of CO2. Such a volume is produced by a modern, lignite-fired power plant within its operation lifetime of approximately 40 years.
Within north-eastern Germany, several saline aquifers of Triassic, Jurassic and Cretaceous age have been evaluated with respect
to their regional occurrence, storage potential and basic reservoir properties. Subsequent to a ranking, considering different
criteria, the anticlinal structure Schweinrich holding suitable saline aquifers of the uppermost Triassic and lowest Jurassic
has been selected from a number of identified candidate sites. According to results of the geological site characterisation,
including structural geological investigations and 3D reservoir modelling, the structure Schweinrich seems to be a suitable
site for industrial large scale CO2 storage. Further data acquisition (new wells and 3D seismics) and research (more detailed and comprehensive modelling) is
needed in order to prove the structural integrity of the storage site and assure long-term safety. 相似文献
22.
Kees Rutten 《Marine Geophysical Researches》1975,2(3):243-263
The relationship between the magnetic anomalies over Iceland and those over Reykjanes Ridge is investigated using the data of the 1965 Dominion Observatory survey. A method is developed for determining the two-dimensionality of the anomalies from the component data measured in this survey. This method is based on testing the first and the second derivative of the magnetic potential with respect to the direction of two-dimensionality, using the component data along a single flight line. Testing the first derivative also yields the direction of two-dimensionality. The outcomes of the two tests (based on a single line) are compared with the observed two-dimensionality (established by narrowly spaced earlier surveys) of Reykjanes Ridge, showing good agreement. As the outcomes of the two tests provide complementary information they are combined into a single factor: A. This factor of two-dimensionality is very low for the anomalies over the shelf of Iceland indicating that the anomalies over Iceland cannot be continued directly into those over Reykjanes Ridge. Over Iceland A is generally low. Over the neovolcanic zone in eastern Iceland twodimensionality is associated with long wavelengths that are not present in the spectrum of the anomalies over Reykjanes Ridge. Thus, Reykjanes Ridge-type anomalies are absent with the exception of the central anomaly. This may not be used as evidence against crustal spreading since the kinematic model proposed by Pálmason for Iceland has a wide transition zone between rock of opposite polarity. The same model if computed for a mid-ocean ridge has narrow transition zones. The larger width of the transition zone blurs the anomalies related to the reversals of the earth magnetic field. 相似文献
23.
Marco Langbroek Peter Jenniskens Leo M. Kriegsman Henk Nieuwenhuis Niek De Kort Jacob Kuiper Wim Van Westrenen Michael E. Zolensky Karen Ziegler Qing‐Zhu Yin Matthew E. Sanborn Josh Wimpenny Akane Yamakawa Sebastiaan J. De Vet Matthias M. M. Meier Kees C. Welten Kunihiko Nishiizumi Marc W. Caffee Aaron S. Burton Jason P. Dworkin Daniel P. Glavin Qinghao Wu Richard N. Zare Alexander Ruf Mourad Harir Philippe Schmitt‐Kopplin 《Meteoritics & planetary science》2019,54(7):1431-1461
A carbonaceous chondrite was recovered immediately after the fall near the village of Diepenveen in the Netherlands on October 27, 1873, but came to light only in 2012. Analysis of sodium and poly‐aromatic hydrocarbon content suggests little contamination from handling. Diepenveen is a regolith breccia with an overall petrology consistent with a CM classification. Unlike most other CM chondrites, the bulk oxygen isotopes are extremely 16O rich, apparently dominated by the signature of anhydrous minerals, distributed on a steep slope pointing to the domain of intrinsic CM water. A small subset plots closer to the normal CM regime, on a parallel line 2 ‰ lower in δ17O. Different lithologies in Diepenveen experienced varying levels of aqueous alteration processing, being less aqueously altered at places rather than more heated. The presence of an agglutinate grain and the properties of methanol‐soluble organic compounds point to active impact processing of some of the clasts. Diepenveen belongs to a CM clan with ~5 Ma CRE age, longer than most other CM chondrites, and has a relatively young K‐Ar resetting age of ~1.5 Ga. As a CM chondrite, Diepenveen may be representative of samples soon to be returned from the surface of asteroid (162173) Ryugu by the Hayabusa2 spacecraft. 相似文献
24.
The importance of three centuries of land-use change for the global and regional terrestrial carbon cycle 总被引:4,自引:0,他引:4
Jelle G. Van Minnen Kees Klein Goldewijk Elke Stehfest Bas Eickhout Gerard van Drecht Rik Leemans 《Climatic change》2009,97(1-2):123-144
Large amounts of carbon (C) have been released into the atmosphere over the past centuries. Less than half of this C stays in the atmosphere. The remainder is taken up by the oceans and terrestrial ecosystems. Where does the C come from and where and when does this uptake occur? We address these questions by providing new estimates of regional land-use emissions and natural carbon fluxes for the 1700–2000 period, simultaneously considering multiple anthropogenic (e.g. land and energy demand) and biochemical factors in a geographically explicit manner. The observed historical atmospheric CO2 concentration profile for the 1700 to 2000 period has been reproduced well. The terrestrial natural biosphere has been a major carbon sink, due to changes in climate, atmospheric CO2, nitrogen and management. Due to land-use change large amounts of carbon have been emitted into the atmosphere. The net effect was an emission of 35 Pg C into the atmosphere for the 1700 to 2000 period. If land use had remained constant at its distribution in 1700, then the terrestrial C uptake would have increased by 142 Pg C. This overall difference of including or excluding land-use changes (i.e. 177 Pg C) comes to more than half of the historical fossil-fuel related emissions of 308 Pg C. Historically, global land-use emissions were predominantly caused by the expansion of cropland and pasture, while wood harvesting (for timber and fuel wood) only played a minor role. These findings are robust even when changing some of the important drivers like the extent of historical land-use changes. Under varying assumptions, land-use emissions over the past three centuries could have increased up to 20%, but remained significantly lower than from other sources. Combining the regional land-use and natural C fluxes, North America and Europe were net C sources before 1900, but turned into sinks during the twentieth century. Nowadays, these fluxes are a magnitude smaller than energy- and industry-related emissions. Tropical regions were C neutral prior to 1950, but then accelerated deforestation turned these regions into major C sources. The energy- and industry-related emissions are currently increasing in many tropical regions, but are still less than the land-use emissions. Based on the presented relevance of the land-use and natural fluxes for the historical C cycle and the significance of fossil-fuel emissions nowadays, there is a need for an integrated approach for energy, nature and land use in evaluating possible climate change mitigation policies. 相似文献
25.
Volume Contents
Contents to Volume 7 相似文献26.
High-field cantilever magnetometry as a tool for the determination of the magnetocrystalline anisotropy of single crystals 总被引:1,自引:0,他引:1
Ftima Martín-Hernndez Iris M. Bominaar-Silkens Mark J. Dekkers Jan Kees Maan 《Tectonophysics》2006,418(1-2):21
Cantilever torque magnetometry is utilized widely in physics and material science for the determination of magnetic properties of thin films and semiconductors. Here, we report on its first application in rock magnetism, namely the determination of K1 and K2 of single crystal octahedra of natural magnetite. The design of cantilever magnetometers allows optimization for the specific research question at hand. For the present study, a cantilever magnetometer was used that enables measurement of samples with a volume up to 64 mm3. It can be inserted into an electromagnet with a maximum field of 2 T. The cantilever spring is suitable for torque values ranging from 7.5 × 10− 7 N·m to 5 × 10− 6 N·m. The torque is detected capacitively; the measured capacitance is converted into torque by using a calibrated feedback coil. The magnetometer allows in-situ rotation of the sample in both directions and is, therefore, also suitable to analyze rotational hysteresis effects.The evaluation of the magnetite anisotropy constants involved Fourier analysis of the torque signal on the magnetite crystals' (001) and (110) planes. The absolute anisotropy constant has been computed using the extrapolation-to-infinite-field method. The value of K1 at room temperature is determined at − 1.28 × 104 [J m− 3] (± 0.13, i.e. 10%) and that of K2 at − 2.8 × 103 [J m− 3] (± 0.1, i.e. 2%). These values concur with earlier determinations that could not provide an instrumental error, in contrast with this work.The cantilever magnetometer performs four times faster than other torque magnetometers used for rock magnetic studies. This makes the instrument also suitable for magnetic fabric analysis. 相似文献
27.
28.
Detlef P. van Vuuren Elke Stehfest Michel G. J. den Elzen Tom Kram Jasper van Vliet Sebastiaan Deetman Morna Isaac Kees Klein Goldewijk Andries Hof Angelica Mendoza Beltran Rineke Oostenrijk Bas van Ruijven 《Climatic change》2011,109(1-2):95-116
The RCP2.6 emission and concentration pathway is representative of the literature on mitigation scenarios aiming to limit the increase of global mean temperature to 2°C. These scenarios form the low end of the scenario literature in terms of emissions and radiative forcing. They often show negative emissions from energy use in the second half of the 21st century. The RCP2.6 scenario is shown to be technically feasible in the IMAGE integrated assessment modeling framework from a medium emission baseline scenario, assuming full participation of all countries. Cumulative emissions of greenhouse gases from 2010 to 2100 need to be reduced by 70% compared to a baseline scenario, requiring substantial changes in energy use and emissions of non-CO2 gases. These measures (specifically the use of bio-energy and reforestation measures) also have clear consequences for global land use. Based on the RCP2.6 scenario, recommendations for further research on low emission scenarios have been formulated. These include the response of the climate system to a radiative forcing peak, the ability of society to achieve the required emission reduction rates given political and social inertia and the possibilities to further reduce emissions of non-CO2 gases. 相似文献
29.
The last few years there has been a growing number of body-wave observations in noise records. In 1973, Vinnik conjectured that P-waves would even be the dominant wavemode, at epicentral distances of about 40 degrees and onwards from an oceanic source. At arrays far from offshore storms, surface waves induced by nearby storms would not mask the body-wave signal and hence primarily P-waves would be recorded. We measured at such an array in Egypt and indeed found a large proportion of P-waves. At the same time, a new methodology is under development to characterize the lithosphere below an array of receivers, without active sources or local earthquakes. Instead, transmitted waves are used which are caused by distant sources. These sources may either be transient or more stationary. With this new methodology, called seismic interferometry, reflection responses are extracted from the coda of transmissions. Combining the two developments, it is clear that there is a large potential for obtaining reflection responses from low-frequency noise. A potential practical advantage of using noise instead of earthquake responses would be that an array only needs to be deployed for a few days or weeks instead of months, to gather enough illumination. We used a few days of continuous noise, recorded with an array in the Abu Gharadig basin, Egypt. We split up the record in three distinct frequency bands and in many small time windows. Using array techniques and taking advantage of all three-component recordings, we could unravel the dominant wavemodes arriving in each time window and in each frequency band. The recorded wavemodes, and hence the noise sources, varied significantly per frequency band, and – to a lesser extent – per time window. Primarily P-waves were detected on the vertical component for two of the three frequency bands. For these frequency bands, we only selected the time windows with a favorable illumination. By subsequently, applying seismic interferometry, we retrieved P-wave reflection responses and delineated reflectors in the crust, the Moho and possibly the Lehmann discontinuity. 相似文献
30.
Grosvenor Mountains 95 howardite pairing group: Insights into the surface regolith of asteroid 4 Vesta 下载免费PDF全文
Nicole G. Lunning Kees C. Welten Harry Y. McSween Jr Marc W. Caffee Andrew W. Beck 《Meteoritics & planetary science》2016,51(1):167-194
Regolithic howardites are analogs for the surface materials of asteroid 4 Vesta, recently mapped by the Dawn spacecraft. Rigorously evaluating pairing of howardites recovered in 1995 in the Grosvenor Mountains (GRO 95), Antarctica, enables an examination of a larger, more representative regolith sample. Previous work on two of the howardites studied here concluded that GRO 95602 and GRO 95535 are solar wind‐rich surface regolith samples and that they are not paired with each other, leading to uncertainty regarding pairing relationships between the other GRO 95 howardites. Based on petrology, cosmic‐ray exposure history, and terrestrial age, four GRO 95 howardites are paired. The paired howardites (GRO 95534, 95535, 95574, 95581) were from a meteoroid with radius of 10–15 cm, a preatmospheric size comparable to that of Kapoeta, the largest known regolithic howardite. The paired GRO 95 howardites contain clasts of at least 18 separate HED lithologies, providing evidence they were assembled from diverse source materials. The total eucrite:diogenite mixing ratio (ratio of all eucrite lithologies to all diogenite lithologies) in the paired GRO 95 howardites is ~2:1. Petrographically determined basaltic eucrite:cumulate eucrite ratios in regolithic howardites, studied here and previously, vary more widely than total eucrite:diogenite ratios. Relative to eucritic pyroxene, plagioclase is depleted in these howardites, which provides evidence that plagioclase is preferentially comminuted in the vestan regolith. The extent of plagioclase depletion could be an indicator of regolith maturity. 相似文献