The characteristic photoluminescence and EPR features of superdeep diamonds (São-Luis,Brazil)     

Olga P. Yuryeva  Mariana I. Rakhmanova  Vladimir A. Nadolinny  Dmitry A. Zedgenizov  Vladislav S. Shatsky  Hiroyuki Kagi  Andrey Yu. Komarovskikh 《Physics and Chemistry of Minerals》2015,42(9):707-722

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Time-scale and state dependence of the carbon-cycle feedback to climate     

Matteo Willeit  Andrey Ganopolski  Daniela Dalmonech  Aideen M. Foley  Georg Feulner 《Climate Dynamics》2014,42(7-8):1699-1713

Climate and atmospheric CO₂ concentration are intimately coupled in the Earth system: CO₂ influences climate through the greenhouse effect, but climate also affects CO₂ through its impact on the amount of carbon stored on land and in the ocean. The change in atmospheric CO₂ as a response to a change in temperature ( $\varDelta CO_{2}/\varDelta T$ ) is a useful measure to quantify the feedback between the carbon cycle and climate. Using an ensemble of experiments with an Earth system model of intermediate complexity we show a pronounced time-scale dependence of $\varDelta CO_{2}/\varDelta T$ . A maximum is found on centennial scales with $\varDelta CO_{2}/\varDelta T$ values for the model ensemble in the range 5–12 ppm °C^?1, while lower values are found on shorter and longer time scales. These results are consistent with estimates derived from past observations. Up to centennial scales, the land carbon response to climate dominates the CO₂ signal in the atmosphere, while on longer time scales the ocean becomes important and eventually dominates on multi-millennial scales. In addition to the time-scale dependence, modeled $\varDelta CO_{2}/\varDelta T$ show a distinct dependence on the initial state of the system. In particular, on centennial time-scales, high $\varDelta CO_{2}/\varDelta T$ values are correlated with high initial land carbon content. A similar relation holds also for the CMIP5 models, although for $\varDelta CO_{2}/\varDelta T$ computed from a very different experimental setup. The emergence of common patterns like this could prove to usefully constrain the climate–carbon cycle feedback.  相似文献   

The peripheral magma chamber of Ploskii Tolbachik,a Kamchatka basaltic volcano: Activity,location and depth,dimensions, and their changes based on magma discharge observations     

S. A. Fedotov  I. S. Utkin  L. I. Utkina 《Journal of Volcanology and Seismology》2011,5(6):369-385

The Klyuchevskoi group of volcanoes (KGV) in Kamchatka is the most powerful existing island arc and subduction zone volcanic center. The Holocene volcanic activity in the southern part of the KGV is concentrated in a large basaltic volcano, Ploskii Tolbachik (PT), altitude 3085 m and in its Tolbachik zone of cinder cones (TZ), length 70 km, which are similar to Hawaiian-type volcanoes and their rifts. A variety of different basalt types are erupted at a rate of 18 × 10⁶ t/yr.  相似文献   

Deep neogene structure and modern seismicity of the southern part of the Koryak Highland academician     

S. A. Fedotov  V. D. Chekhovich  A. V. Egorkin 《Doklady Earth Sciences》2011,437(2):455-459

The Northern Kamchatka and southern part of the Koryak Highland is considered to be an accretion-collision system in the Late Cretaceous and Cenozoic the development of which was caused by the subsequent accretion of various large terranes to the Asian continental margin. The Paleogene Goven Terrane accreted in the Miocene closes this system. Its boundary with the Olyutor Terrane is hidden under the Cenozoic sediments of the Il’pino-Pakhachino interarc trough. The destructive Khaily (March 8, 1991) and Olyutor (April 20, 2006) earthquakes are characterized by an aftershock area extended in the northeastern direction along the axial part of the Il’pino-Pakhachino trough. The aftershock area was intersected by a profile of the earthquake converted-wave method (ECWM) the interpretation of which reveals a correlation loss of the deep reflecting horizons under this area and three faults dipping to the southeast on seismograms.  相似文献   

The Critical Richardson Number and Limits of Applicability of Local Similarity Theory in the Stable Boundary Layer   总被引：7，自引：7，他引：0  

Andrey A. Grachev  Edgar L Andreas  Christopher W. Fairall  Peter S. Guest  P. Ola G. Persson 《Boundary-Layer Meteorology》2013,147(1):51-82

Measurements of atmospheric turbulence made over the Arctic pack ice during the Surface Heat Budget of the Arctic Ocean experiment (SHEBA) are used to determine the limits of applicability of Monin–Obukhov similarity theory (in the local scaling formulation) in the stable atmospheric boundary layer. Based on the spectral analysis of wind velocity and air temperature fluctuations, it is shown that, when both the gradient Richardson number, Ri, and the flux Richardson number, Rf, exceed a ‘critical value’ of about 0.20–0.25, the inertial subrange associated with the Richardson–Kolmogorov cascade dies out and vertical turbulent fluxes become small. Some small-scale turbulence survives even in this supercritical regime, but this is non-Kolmogorov turbulence, and it decays rapidly with further increasing stability. Similarity theory is based on the turbulent fluxes in the high-frequency part of the spectra that are associated with energy-containing/flux-carrying eddies. Spectral densities in this high-frequency band diminish as the Richardson–Kolmogorov energy cascade weakens; therefore, the applicability of local Monin–Obukhov similarity theory in stable conditions is limited by the inequalities Ri < Ri _cr and Rf < Rf _cr. However, it is found that Rf _cr  =  0.20–0.25 is a primary threshold for applicability. Applying this prerequisite shows that the data follow classical Monin–Obukhov local z-less predictions after the irrelevant cases (turbulence without the Richardson–Kolmogorov cascade) have been filtered out.  相似文献   

A Seti Correspondent Helps us to Discover their Signals, Lost in the Noise of our Receivers (A working hypothesis)     

N.T. Petrovich 《Astrophysics and Space Science》1997,252(1-2):59-66

It could be that SETI signals have arrived at the Earth, but are lower than the noise level, and our receivers cannot detect them. We analyze the situation when a SETI correspondent sends signals that can be accumulated upon reception, permitting detection of even very weak signals. It is shown that using this method, we can already transmit SETI signals over our entire Galaxy.  相似文献   

Systematic Errors of High–Precision Photometric Catalogues     

Aleksey Mironov  Andrey Zakharov 《Astrophysics and Space Science》2002,280(1-2):71-76

A very accurate imitation of Hipparcos and Tycho Hp, B _T, andV _T magnitudes was made using W, B, V, R magnitudes from the Tien Shan photometric catalogue. The calculated magnitudes were compared to the observed ones. It is shown that there are systematic differences between calculated and observed magnitudes. The systematic errors are supposed to be bound up with the sky scanning procedure on the Hipparcos satellite. Polynomials in powers of coordinates have been proposed to take into account the systematic errors. 6558 stars have been found to be appropriate high-precision photometric standards. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Intergranular diamonds derived from partial melting of crustal rocks at ultrahigh-pressure metamorphic conditions     

Andrey V. Korsakov  Karel Theunissen  Larissa V. Smirnova 《地学学报》2004,16(3):146-151

By reporting for the first time intergranular diamond in quartz–feldspar (Qtz–Kfs) aggregates, the processes of metamorphic diamond formation have to be reconsidered. Based on their Kfs/Qtz ratio, the texture of these aggregates are proposed to result from ‘granitic’ melt with a calculated composition that corresponds well with that of experimental data for the pelitic system. Taking into account experiments on CO₂ solubility in silicate melt under ultrahigh‐pressure conditions, a granitic melt is further suggested to act as a crystallization medium as well as a transport medium for producing metamorphic diamond.  相似文献   

Southern East Siberia Pliocene–Quaternary faults: Database, analysis and inference     

Oksana V. Lunina  ;Riccardo Caputo  ;Anton A. Gladkov  ;Andrey S. Gladkovt 《地学前缘(英文版)》2014,5(4):605-619

This paper presents the first release of an Informational System（IS）devoted to the systematic collection of all available data relating to Pliocene-Quaternary faults in southern East Siberia,their critical analysis and their seismotectonic parameterization.The final goal of this project is to form a new base for improving the assessment of seismic hazard and other natural processes associated with crustal deformation.The presented IS has been exploited to create a relational database of active and conditionally active faults in southern East Siberia（between 100°-114° E and 50°-57° N）whose central sector is characterized by the highly seismic Baikal rift zone.The information within the database for each fault segment is organized as distinct but intercorrelated sections（tables,texts and pictures,etc.）and can be easily visualized as HTML pages in offline browsing.The preliminary version of the database distributed free on disk already highlights the general fault pattern showing that the Holocene and historical activity is quite uniform and dominated by NE-SW and nearly E-W trending faults;the former with a prevailing dip-slip normal kinematics,while the latter structures are left-lateral strike-slip and oblique-slip（with different proportion of left-lateral and normal fault slip components）.These faults are mainly concentrated along the borders of the rift basins and are the main sources of moderate-to-strong（M≥5.5）earthquakes on the southern sectors of East Siberia in recent times.As a whole,based on analyzing the diverse fault kinematics and their variable spatial distribution with respect to the overall pattern of the tectonic structures formed and/or activated during the late Pliocene-Quaternary,we conclude they were generated under a regional stress field mainly characterized by a relatively uniform NW-SE tension,but strongly influenced by the irregular hard boundary of the old Siberian craton.The obtained inferences are in an agreement with the existing models of the development of  相似文献   

Geochemical signal of seasonality in annually laminated organic- carbonate sediments in Shira lake(Khakasia)     

Ivan KALUGIN  Andrey DARIN  Denis ROGOZIN  Gennady TRET’YAKOV 《《地质学报》英文版》2014,88(Z1):12-13

正1 Introduction The most valuable for the task of climate reconstruction are the time series with an annual resolution,which allows to reveal natural periodicity and pass to the search for mechanisms of regional and global climatic changes.Bottom sediments of lakes are one of the best climate archives in addition to tree ring series,ice cores etc.  相似文献