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1.
Strong vibrations of the Earth’s crust in the frequency range of 7–9 Hz, referred to as the “voice of the sea,” have been recorded in the course of processing synchronous experimental data obtained during recording of variations in the deformation of the Earth’s crust using a shore laser strainmeter, atmosphere pressure variations using a laser nanobarograph, and hydrosphere pressure variations using a laser meter for hydrospheric pressure and wind velocity variations. The nature of these vibrations and their transformation to adjacent geospheres have been discussed. 相似文献
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V. S. Zakharov 《Moscow University Geology Bulletin》2013,68(5):282-288
The spatial and temporal peculiarities of seismic “nails” are analyzed. Some nails are related to strong earthquakes, or volcanic eruptions, while some do not show any coincidence with any fault zone or other tectonic structures. In some cases, poorly expressed trends in the depths of earthquake occurrence sequences occur. Based on the calculation of the Hurst exponent, a stable tendency in the order sequence for the depths of hypocenters that form a nail has been revealed. This tendency is consistent with self-organization models, which demonstrate positive feedback during interactions between fluid flows and tectonic deformations and have been used to explain the earthquake generation mechanism. The peculiarities of changes in earthquake numbers on the day when a nail is formed agree well with the acoustical emission dynamics during earthquake triggering through water injections, based on the long-term experimental data. The most probable mechanism that generates the seismic nails that are not related to strong earthquakes is seismic activation under the effects of fluids. 相似文献
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Yu. N. Parijskij A. I. Kopylov A. V. Temirova N. S. Soboleva O. P. Zhelenkova O. V. Verkhodanov W. M. Goss T. A. Fatkhullin 《Astronomy Reports》2010,54(8):675-695
We present the results of spectroscopy of 71 objects with steep and ultra-steep spectra (α < −0.9, S ∝ ν
α) from the “Big Trio” (RATAN-600-VLA-BTA) project, performed with the “Scorpio” spectrograph on the 6-m telescope of the Special
Astrophysical Observatory (Russian Academy of Sciences). Redshifts were determined for these objects. We also present several
other parameters of the sources, such as their R magnitudes, maximum radio sizes in seconds of arc, flux densities at 500, 1425, and 3940 MHz, radio luminosities at 500 and
3940 MHz, and morphology. Of the total number of radio galaxies studied, four have redshifts 1 ≤ z < 2, three have 2 ≤ z < 3, one has 3 ≤ z < 4, and one has z = 4.51. Thirteen sources have redshifts 0.7 < z < 1 and 15 have 0.2 < z < 0.7.Of all the quasars studied, five have redshifts 0.7 < z < 1, seven have 1 ≤ z < 2, four have 2 ≤ z < 3, and one has z = 3.57. We did not detect any spectral lines for 17 objects. 相似文献
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V. A. Bol’shakov 《Stratigraphy and Geological Correlation》2017,25(6):659-678
The terms “glaciation” and “interglacial” are considered from the point of view of palaeoclimatic proxies obtained from the Pleistocene deep-water and continental deposits. It is shown that the crucial factor in substantiation of these notions is determination of the cause-and-effect mechanism in the considered climatic oscillations. It is noted that oxygen isotope data on deep-water deposits have an undoubted advantage because a more accurate quantitative estimate of climatic oscillation parameters can be made on their basis. It is concluded that the role played by quantitative estimates of palaeoclimatic changes, represented by, first of all, amplitude and time characteristics of climatic oscillations, will become more significant as the methods of paleogeographic studies of both continental and deep-water deposits of the Pleistocene improve; in contrast, the formal determination of the rank of palaeoclimatic oscillations will become less significant. Special attention is paid to the cases of misfits between the Pleistocene deep-water and continental paleoclimatic records and to the necessity to make them consistently as good as possible, especially in the case of Early Pleistocene deposits. 相似文献
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Astronomy Reports - As a rule, sigmoidal structures in the colar corona, i.e., structures having the appearance of an S or reversed S, are taken to be evidence for twisting of the magnetic-field... 相似文献
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Giovanni Zanchetta Carlo Giraudi Roberto Sulpizio Michel Magny Russell N. Drysdale Laura Sadori 《Quaternary Research》2012,78(2):236-247
A study of six tephra layers discovered in different deposits between 1600 and 2700 m a.s.l. in the Apennine chain in central Italy allowed precise stratigraphic constraints on environmental and climatic changes between ca. 4.5 and 3.8 cal ka BP. Chemical analyses allowed the correlation of these tephra layers with the eruptions of Agnano Mt Spina (AMST) from Phlegrean Field and Avellino (AVT) from Somma–Vesuvius. Major environmental changes in the high mountains of the Central Apennines occurred just after the deposition of the AMST and predate the deposition of the AVT. At this time, renewed growth of the Calderone Glacier occurred, marking the onset of the Apennine “Neoglacial”. The presence of the AMST and AVT enabled us to make a precise, physical correlation with other archives in central Italy. Synchronization of records between sites showed that the period intervening the deposition of the AMST and AVT layers coincided with environmental changes that were not always exactly in phase. This highlights the fact that stratigraphic correlations using only radiocarbon chronologies (the most common method used for dating archives during the Holocene) could produce erroneous correlation of events, giving rise to oversimplified paleoclimatic reconstructions. 相似文献
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《Geoforum》2017
Coworking spaces (CWS) and the associated practice of coworking, have emerged in numerous forms and various urban contexts to critically challenge traditional concepts of the workplace and location of creative work, while simultaneously confronting the way in which creative workers interact with and relate to each other as well as with space and to place. Heralded as a solution to increasingly atomised work patterns, CWS are imagined and presented as spaces of serendipitous encounter, spontaneous exchange and collaboration. Nonetheless, little is known about how coworking positively supports workers and how coworking relates to wider urban transformation processes has been largely un-researched. This paper contributes to a critical discussion through empirical analysis of a project aimed at establishing new creative CWS in city-centre locations across SE England. The study adopts a novel approach using Q-methodology. Motivations for coworking and benefits (or dis-benefits) of co-location are assessed, as is the extent to which coworking facilitates interactional effects and wider neighbourhood interactions. In particular, the role of the CWS manager as “mediator” is explored. Coworker benefits relate primarily to peer-interaction and support rather than formal collaboration. While CWS managers play a key connecting role, also ensuring coworker complementarity and compatibility, the coworker profile (motivations, needs, experiences) ultimately influences outcomes. The study cautions against the use of CWS as “quick fix” urban renewal tools, with little indication that the benefits of coworking reach beyond immediate members or that linkages are easily established between coworkers and local (resident or business) communities. 相似文献
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We consider perturbations in interstellar gas excited by the gravitational field of the spiral-density wave that is responsible
for the Galactic arms, taking into account thermal effects. Under the conditions of fairly efficient cooling, the reaction
of the gas to the perturbing field is non-trivial: the thickness of the gaseous layer is reduced in the region of the Galactic
disk where the density of the gas is enhanced. We call this effect “self-focusing,” and explain it using observational results
for the Galactic radio emission in the 21 cm line. Under our assumptions, we find the control parameter (δ) governing the relationship between perturbations of the thickness of the gaseous disk and the gas density in the vicinity
of the Galactic equator, i.e., this parameter shows whether the correlation between these quantities is positive or negative,
and provides important additional information on the thermal properties of the medium. It can be used as a diagnostic in joint
studies of Galactic structure and large-scale features of the interstellar gas. Estimates for the typical Galactic parameters
show that the effect of self-focusing should be clearly manifest in the Galaxy. 相似文献
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V. A. Zubakov 《Stratigraphy and Geological Correlation》2011,19(1):108-124
An international scientific conflict has arisen around the International Stratigraphic Scale, the main document that regulates
the rules of reading of geological records and, hence, concerns all Earth sciences. The matter of debate is the geological
time scale of 2004, developed by the International Commission on Stratigraphy, where the Quaternary system was abandoned. This ICS decision triggered a protest among Quaternary geologists, members of
INQUA, and became the subject of much controversy. This article provides a comprehensive analysis of the Quaternary problem
and proposes a reasonable scientific solution that may be appropriate for both parties. 相似文献
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David E. Alexander 《Natural Hazards》2014,72(2):1159-1173
The trial and conviction of seven public officials in L’Aquila, central Italy, for having allegedly given out misleading and incorrect information to the public before the 6 April 2009 earthquake has proved to be one of the most momentous developments of recent times in science and disaster risk reduction—and also one of the most misunderstood. It highlights the difficulty in transforming the findings of the earth sciences, which are often characterised by uncertainty, into information that can be used to protect ordinary citizens. This paper describes those elements of the disaster at L’Aquila which are pertinent to the trial and the legal proceedings that followed them. It analyses the political, social and scientific context of the trial, and the reaction of scientists and their institutions in Italy and other countries. I conclude that the defendants were tried as responsible public officials, not as scientists. The mass media in Italy and abroad tended to insist that what was on trial was the ability to predict earthquakes, and this had an enormous influence on the opinion of scientists in many different places. However, the trial was actually about the apparently fatal consequences of misleading the public with “incomplete, imprecise and contradictory information”, as the prosecutors put it. I believe that much of the international reaction to the trial was misguided because it was based on incomplete, second-hand information about the proceedings. If scientists were to make judgements on their own work in such a superficial manner, the results would be highly unreliable and public faith in science would plummet. 相似文献
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The recent publication of evidence for a new mechanism producing background radio emission of the Galaxy at centimeter wavelengths (in addition to synchrotron radiation, free—free transitions in ionized gas, and the weak radio emission of standard dust) gave rise to a strong reaction among observers, and requires independent experimental verification. This signal is of special concern in connection with studies of the polarization of the cosmic microwave background (CMB) using new-generation experiments. We have derived independent estimates of the validity of the “spinning-dust” hypothesis (dipole emission of macromolecules) using multi-frequency RATAN-600 observations. Test studies in the Perseus molecular cloud show evidence for anomalous extended emission in the absence of strong radio sources (compact HII regions) that could imitate an anomalous radio spectrum in this region. A statistical analysis at centimeter wavelengths over the Ratan Zenith Field shows that the upper limit for the polarized noise from this new component in the spinning-dust hypothesis is unlikely to exceed 1 µK at wavelengths of 1 cm or shorter on the main scales of the EE mode of Sakharov oscillations. Thus, this emission should not hinder studies of this mode, at least to within several percent of the predicted level of polarization of the CMB emission. 相似文献
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Dolgikh G. I. Chupin V. A. Gusev E. S. Ovcharenko V. V. 《Doklady Earth Sciences》2021,501(2):1087-1090
Doklady Earth Sciences - The generation zones of “voice of the sea” microseisms of three typhoons were determined from the field data using a two-coordinate laser strainmeter. From... 相似文献
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Around 8500 cal years BP, at the time of the maximum of the African Humid Period, lakes and wetlands expanded in the present-day Sahara while large paleodrainages were formed or re-actived, in response to an orbitally-induced increase in monsoon rainfall. It has been suggested that the direct consequence of this increase in rainfall was the northward displacement of the Sahara/Sahel boundary, thought to have reached 23°N in central and eastern Africa. Here, we show a more complex situation characterized by an increase in biodiversity as the desert accommodated more humid-adapted species from tropical forests and wooded grasslands: tropical plant species now found some 400 to 500 km to the south probably entered the desert as gallery-forest formations along rivers and lakes where they benefited from permanent fresh water. At the same time, Saharan trees and shrubs persisted, giving rise to a vegetation that has no analogue today. In this article, we present distribution maps of selected plant species to show both the amplitude of the vegetation change compared to the present and the composition of the past plant communities. We also estimate the migration rate of tropical plant taxa to their northernmost position in the Sahara. This study is based on the use of several data sets: a data set of the modern plant distribution in northern Africa and a data set of modern and fossil pollen sites (from the African Pollen Database, http://fpd.mediasfrance.org/ and http://medias.obs-mip.fr/apd/). 相似文献
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N. V. Goreva A. S. Alekseev T. N. Isakova O. L. Kossovaya 《Stratigraphy and Geological Correlation》2009,17(1):43-61
Micro- and macrofauna remains were studied from transitional deposits of Moscovian and Kasimovian Stages in the Donskaya Luka (Volgograd Region). The preliminary analysis of microfauna showed that “sub-Triticites Beds” of the Donskaya Luka contain fusulinid and conodont assemblages enabling correlation of the Middle and Upper Carboniferous deposits in the study region with the type sections of Moscow area and Donbass. Conodonts from the “sub-Triticites Beds” stratotype were studied for the first time. As is established, upper part of the Sukhov Fm. and the base of the Seleznev Fm. belong to the Protriticites pseudomontiparus-Obsoletes obsoletus Zone. Based on fusulinids, higher parts of the Seleznev Fm. belong to the Montiparus Zone of the Khamovnikian Substage, whereas conodonts suggest their correlation with lower part of the Khamovnikian Substage, i.e., with the Ratmirovo Fm. or a basal part of the Neverovo Fm. Middle part of the Seleznev Fm. is correlated to middle cycle of the Neverovo Fm. of the Khamovnikian Substage in Moscow area. The Middle-Upper Carboniferous boundary deposits of the Donskaya Luka are represented by deposits of extremely shallow-water settings and contain only sporadic microfauna. These sections cannot be considered as possible candidates for the GSSP of the Kasimovian Stage base. 相似文献
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Grant M.Young 《地学前缘(英文版)》2015,6(4)
The second half of the Ediacaran period began with a large impact e the Acraman impact in South Australia, which was accompanied by a negative d13Ccarb anomaly and an extinction-radiation event involvi... 相似文献