Age of amphibolites associated with alpine peridotites in the Dinaride ophiolite zone,Yugoslavia   总被引：1，自引：0，他引：1  

Marvin A. Lanphere  Robert G. Coleman  Steven Karamata  Jakob Pamić 《Earth and Planetary Science Letters》1975,26(3):271-276

Amphibolites associated with alpine peridotites in the Central Ophiolite zone in Yugoslavia have K-Ar ages of 160–170 m.y. These amphibolites and associated peridotites underwent deep-seated metamorphism prior to tectonic emplacement into the sedimentary-volcanic assemblage of the Dinarides. The alpine peridotites and associated local rocks of the ophiolite suite are interpreted as Jurassic oceanic crust and upper mantle.  相似文献   

Preface     

Jakob Flury  Reiner Rummel 《Earth, Moon, and Planets》2004,94(1-2):1-1

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Science Requirements on Future Missions and Simulated Mission Scenarios   总被引：4，自引：0，他引：4  

Nico Sneeuw  Jakob Flury  Reiner Rummel 《Earth, Moon, and Planets》2004,94(1-2):113-142

The science requirements on future gravity satellite missions, following from the previous contributions of this issue, are summarized and visualized in terms of spatial scales, temporal behaviour and accuracy. This summary serves the identification of four classes of future satellite mission of potential interest: high-altitude monitoring, satellite-to-satellite tracking, gradiometry, and formation flights. Within each class several variants are defined. The gravity recovery performance of each of these ideal missions is simulated. Despite some simplifying assumptions, these error simulations result in guidelines as to which type of mission fulfils which requirements best.  相似文献   

The economics of decarbonizing the energy system—results and insights from the RECIPE model intercomparison     

Gunnar Luderer  Valentina Bosetti  Michael Jakob  Marian Leimbach  Jan C. Steckel  Henri Waisman  Ottmar Edenhofer 《Climatic change》2012,114(1):9-37

This paper synthesizes the results from the model intercomparison exercise among regionalized global energy-economy models conducted in the context of the RECIPE project. The economic adjustment effects of long-term climate policy are investigated based on the cross-comparison of the intertemporal optimization models ReMIND-R and WITCH as well as the recursive dynamic computable general equilibrium model IMACLIM-R. A number of robust findings emerge. If the international community takes immediate action to mitigate climate change, the costs of stabilizing atmospheric CO₂ concentrations at 450?ppm (roughly 530?C550?ppm-e) discounted at 3% are estimated to be 1.4% or lower of global consumption over the twenty-first century. Second best settings with either a delay in climate policy or restrictions to the deployment of low-carbon technologies can result in substantial increases of mitigation costs. A delay of global climate policy until 2030 would render the 450?ppm target unachievable. Renewables and CCS are found to be the most critical mitigation technologies, and all models project a rapid switch of investments away from freely emitting energy conversion technologies towards renewables, CCS and nuclear. Concerning end use sectors, the models consistently show an almost full scale decarbonization of the electricity sector by the middle of the twenty-first century, while the decarbonization of non-electric energy demand, in particular in the transport sector remains incomplete in all mitigation scenarios. The results suggest that assumptions about low-carbon alternatives for non-electric energy demand are of key importance for the costs and achievability of very low stabilization scenarios.  相似文献   

Post-starburst galaxies: more than just an interesting curiosity     

Vivienne Wild  C. Jakob Walcher  Peter H. Johansson  Laurence Tresse  Stéphane Charlot  Agnieszka Pollo  Olivier Le Fèvre  Loic de Ravel 《Monthly notices of the Royal Astronomical Society》2009,395(1):144-159

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High‐resolution bathymetric mapping reveals subaqueous glacial landforms in the Arctic alpine lake Tarfala,Sweden     

Nina Kirchner  Riko Noormets  Jakob Kuttenkeuler  Elias Strandell Erstorp  Erik Schytt Holmlund  Gunhild Rosqvist  Per Holmlund  Marika Wennbom  Torbjrn Karlin 《第四纪科学杂志》2019,34(6):452-462

In Arctic alpine regions, glacio‐lacustrine environments respond sensitively to variations in climate conditions, impacting, for example,glacier extent and rendering former ice‐contact lakes into ice distal lakes and vice versa. Lakefloors may hold morphological records of past glacier extent, but remoteness and long periods of ice cover on such lakes make acquisition of high‐resolution bathymetric datasets challenging. Lake Tarfala and Kebnepakte Glacier, located in the Kebnekaise mountains, northern Sweden, comprise a small, dynamic glacio‐lacustrine system holding a climate archive that is not well studied. Using an autonomous surface vessel, a high‐resolution bathymetric dataset for Lake Tarfala was acquired in 2016, from which previously undiscovered end moraines and a potential grounding line feature were identified. For Kebnepakte Glacier, structure‐from‐motion photogrammetry was used to reconstruct its shape from photographs taken in 1910 and 1945. Combining these methods connects the glacial landform record identified at the lakefloor with the centennial‐scale dynamic behaviour of Kebnepakte Glacier. During its maximum 20^th century extent, attained c. 1910, Kebnepakte Glacier reached far into Lake Tarfala, but had retreated onto land by 1945, at an average of 7.9 m year^–1. Copyright © 2019 John Wiley & Sons, Ltd.  相似文献   

Bleaching of the post‐IR IRSL signal: new insights for feldspar luminescence dating     

Romée H. Kars  Tony Reimann  Christina Ankjærgaard  Jakob Wallinga 《Boreas: An International Journal of Quaternary Research》2014,43(4):780-791

Post‐infrared (pIR) stimulated luminescence dating of sedimentary feldspar largely avoids the effects of anomalous fading that affect conventional infrared stimulated luminescence (IRSL) dating. However, optical resetting of pIR signals is more difficult than resetting the conventional IRSL signal, which may undermine the crucial assumption that pIR signals were effectively bleached upon deposition and burial of sediment grains. In this study, we quantify the bleaching properties of several pIR signals on various samples using laboratory‐simulated bleaching in full sunlight and water‐attenuated sunlight. Our data show that bleaching is most efficient under full spectrum conditions for all pIR signals and that pIR signals measured at elevated temperature are increasingly harder to bleach than IR and pIR signals measured at low temperature (e.g. IR at 50°C). All bleaching curves exhibit a very slow and steady decrease, indicating that a fixed un‐bleachable residual level cannot be reached within the 11 days of solar simulator exposure undertaken here. We show that the magnitude of a laboratory‐determined residual dose depends on the adopted bleaching protocol and cannot be used as a proxy for the dose that remains in the sample at the time of burial (remnant dose). Our data emphasize the importance of finding a balance between sufficient signal stability and a minimized contribution of a remnant dose when using pIR procedures for feldspar luminescence dating.  相似文献   

Simplification and Validation of a Spectral-Tensor Model for Turbulence Including Atmospheric Stability   总被引：1，自引：1，他引：0  

Abhijit Chougule  Jakob Mann  Mark Kelly  Gunner C. Larsen 《Boundary-Layer Meteorology》2018,167(3):371-397

A spectral-tensor model of non-neutral, atmospheric-boundary-layer turbulence is evaluated using Eulerian statistics from single-point measurements of the wind speed and temperature at heights up to 100 m, assuming constant vertical gradients of mean wind speed and temperature. The model has been previously described in terms of the dissipation rate \(\epsilon \), the length scale of energy-containing eddies \(\mathcal {L}\), a turbulence anisotropy parameter \(\varGamma \), the Richardson number Ri, and the normalized rate of destruction of temperature variance \(\eta _\theta \equiv \epsilon _\theta /\epsilon \). Here, the latter two parameters are collapsed into a single atmospheric stability parameter z / L using Monin–Obukhov similarity theory, where z is the height above the Earth’s surface, and L is the Obukhov length corresponding to \(\{Ri,\eta _\theta \}\). Model outputs of the one-dimensional velocity spectra, as well as cospectra of the streamwise and/or vertical velocity components, and/or temperature, and cross-spectra for the spatial separation of all three velocity components and temperature, are compared with measurements. As a function of the four model parameters, spectra and cospectra are reproduced quite well, but horizontal temperature fluxes are slightly underestimated in stable conditions. In moderately unstable stratification, our model reproduces spectra only up to a scale \(\sim \) 1 km. The model also overestimates coherences for vertical separations, but is less severe in unstable than in stable cases.  相似文献   

Spatio‐temporal tracer variability in the glacier melt end‐member — How does it affect hydrograph separation results?          下载免费PDF全文

Jan Schmieder  Jakob Garvelmann  Thomas Marke  Ulrich Strasser 《水文研究》2018,32(12):1828-1843

Geochemical and isotopic tracers were often used in mixing models to estimate glacier melt contributions to streamflow, whereas the spatio‐temporal variability in the glacier melt tracer signature and its influence on tracer‐based hydrograph separation results received less attention. We present novel tracer data from a high‐elevation catchment (17 km², glacierized area: 34%) in the Oetztal Alps (Austria) and investigated the spatial, as well as the subdaily to monthly tracer variability of supraglacial meltwater and the temporal tracer variability of winter baseflow to infer groundwater dynamics. The streamflow tracer variability during winter baseflow conditions was small, and the glacier melt tracer variation was higher, especially at the end of the ablation period. We applied a three‐component mixing model with electrical conductivity and oxygen‐18. Hydrograph separation (groundwater, glacier melt, and rain) was performed for 6 single glacier melt‐induced days (i.e., 6 events) during the ablation period 2016 (July to September). Median fractions (±uncertainty) of groundwater, glacier melt, and rain for the events were estimated at 49±2%, 35±11%, and 16±11%, respectively. Minimum and maximum glacier melt fractions at the subdaily scale ranged between 2±5% and 76±11%, respectively. A sensitivity analysis showed that the intraseasonal glacier melt tracer variability had a marked effect on the estimated glacier melt contribution during events with large glacier melt fractions of streamflow. Intra‐daily and spatial variation of the glacier melt tracer signature played a negligible role in applying the mixing model. The results of this study (a) show the necessity to apply a multiple sampling approach in order to characterize the glacier melt end‐member and (b) reveal the importance of groundwater and rainfall–runoff dynamics in catchments with a glacial flow regime.  相似文献   

Do landslides follow landslides? Insights in path dependency from a multi-temporal landslide inventory   总被引：1，自引：0，他引：1  

Jalal Samia  Arnaud Temme  Arnold Bregt  Jakob Wallinga  Fausto Guzzetti  Francesca Ardizzone  Mauro Rossi 《Landslides》2017,14(2):547-558

Landslides are a major category of natural disasters, causing loss of lives, livelihoods and property. The critical roles played by triggering (such as extreme rainfall and earthquakes), and intrinsic factors (such as slope steepness, soil properties and lithology) have previously successfully been recognized and quantified using a variety of qualitative, quantitative and hybrid methods in a wide range of study sites. However, available data typically do not allow to investigate the effect that earlier landslides have on intrinsic factors and hence on follow-up landslides. Therefore, existing methods cannot account for the potentially complex susceptibility changes caused by landslide events. In this study, we used a substantially different alternative approach to shed light on the potential effect of earlier landslides using a multi-temporal dataset of landslide occurrence containing 17 time slices. Spatial overlap and the time interval between landslides play key roles in our work. We quantified the degree to which landslides preferentially occur in locations where landslides occurred previously, how long such an effect is noticeable, and how landslides are spatially associated over time. We also investigated whether overlap with previous landslides causes differences in landslide geometric properties. We found that overlap among landslides demonstrates a clear legacy effect (path dependency) that has influence on the landslide affected area. Landslides appear to cause greater susceptibility for follow-up landslides over a period of about 10  years. Follow-up landslides are on average larger and rounder than landslides that do not follow earlier slides. The effect of earlier landslides on follow-up landslides has implications for understanding of the landslides evolution and the assessment of landslide susceptibility.  相似文献