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941.
<Emphasis Type="Italic">M</Emphasis><Subscript>W</Subscript>9 Tohoku earthquake in 2011 in Japan: precursors uncovered by natural time analysis 下载免费PDF全文
Panayiotis A. Varotsos Nicholas V. Sarlis Efthimios S. Skordas Mary S. Lazaridou-Varotsos 《地震科学(英文版)》2017,30(4):183-191
This paper reviews the precursory phenomena of the 2011 M W9 Tohoku earthquake in Japan that emerge solely when we analyze the seismicity data in a new time domain termed natural time. If we do not consider this analysis, important precursory changes cannot be identified and hence are missed. Natural time analysis has the privilege that enables the introduction of an order parameter of seismicity. In this frame, we find that the fluctuations of this parameter exhibit an unprecedented characteristic change, i.e., an evident minimum, approximately two months before Tohoku earthquake, which strikingly is almost simultaneous with unique anomalous geomagnetic field variations recorded mainly on the z component. This is consistent with our finding that such a characteristic change in seismicity appears when a seismic electric signal (SES) activity of the VAN method (from the initials of Varotsos, Alexopoulos, Nomicos) initiates, and provides a direct confirmation of the physical interconnection between SES and seismicity. 相似文献
942.
B. A. Kagan A. A. Timofeev E. V. Sofina 《Izvestiya Atmospheric and Oceanic Physics》2010,46(5):652-662
The modeling results of surface and internal M2 tides for summer and winter periods in the Arctic Ocean (AO) are presented. We employed a modified version of the three-dimensional
finite-element hydrothermodynamic model QUODDY-4 differing from the original model by using a rotated (instead of spherical)
coordinate system and by considering the equilibrium-tide effects. It has been shown that the modeling results for the surface
tide differs little from the results obtained earlier by other authors. According to these results, the amplitudes of internal
tidal waves (ITWs) in the AO are significantly lower than in other oceans and the ITWs proper have the character of trapped
waves. Their source of generation is located at the continental slope northwest of the New Siberian Islands. Our results are
consistent with the fields of average (over a tidal cycle) and integral (by depth) densities of baroclinic tidal energy, the
maximum baroclinic tidal velocity, and the coefficient of diapycnic mixing. The local rate of baroclinic tidal energy dissipation
at the AO ridges increases as it approaches the bottom, as was observed on Mid-Atlantic and Hawaii ridges (but merely within
the bottom boundary layer) and is two to three orders of magnitude lower than in other oceans. The ITW degeneration scale
in the AO is several hundreds of kilometers in summer and winter, remaining within the range of its values between 100 and
1000 km in mid- and low-latitude oceans. In both seasons, the integral (over the AO area) rate of baroclinic tidal energy
dissipation is two orders of magnitude lower than the global estimate (2.5 × 1012 W). 相似文献
943.
Deshcherevskii A. V. Modin I. N. Sidorin A. Ya. 《Izvestiya Atmospheric and Oceanic Physics》2018,54(10):1490-1511
Izvestiya, Atmospheric and Oceanic Physics - In geophysical studies, particularly when searching for precursors of earthquakes, there are problems of investigating the geoelectric structure of the... 相似文献
944.
945.
M. Déqué R. G. Jones M. Wild F. Giorgi J. H. Christensen D. C. Hassell P. L. Vidale B. Rockel D. Jacob E. Kjellström M. de. Castro F. Kucharski B. van den Hurk 《Climate Dynamics》2005,25(6):653-670
Four high resolution atmospheric general circulation models (GCMs) have been integrated with the standard forcings of the
PRUDENCE experiment: IPCC-SRES A2 radiative forcing and Hadley Centre sea surface temperature and sea-ice extent. The response
over Europe, calculated as the difference between the 2071–2100 and the 1961–1990 means is compared with the same diagnostic
obtained with nine Regional Climate Models (RCM) all driven by the Hadley Centre atmospheric GCM. The seasonal mean response
for 2m temperature and precipitation is investigated. For temperature, GCMs and RCMs behave similarly, except that GCMs exhibit
a larger spread. However, during summer, the spread of the RCMs—in particular in terms of precipitation—is larger than that
of the GCMs. This indicates that the European summer climate is strongly controlled by parameterized physics and/or high-resolution
processes. The temperature response is larger than the systematic error. The situation is different for precipitation. The
model bias is twice as large as the climate response. The confidence in PRUDENCE results comes from the fact that the models
have a similar response to the IPCC-SRES A2 forcing, whereas their systematic errors are more spread. In addition, GCM precipitation
response is slightly but significantly different from that of the RCMs. 相似文献
946.
A. V. Kiryukhin N. P. Asaulova O. B. Vereina A. Yu. Polyakov 《Journal of Volcanology and Seismology》2014,8(3):156-167
It is shown that the productive reservoir received considerable quantities of meteoric water during the operation of the Pauzhetka geothermal field (1960–2007), which amounted to 30% of the total with-drawal of heat carrier. This led to cooling of the productive reservoir and reduced steam extraction. Modeling the operation process with the infiltration zones sealed shows that steam extraction can be enhanced by 23.2%. Multi-option modeling for the operation of the Dachnyi site of the Mutnovskii geothermal field shows that the most-likely scenario is infiltration of meteoric water with a discharge of about 60 kg/s into the productive reservoir from above. These results are consistent with the decrease in the steam concentration during the first 4 years of operation. 相似文献
947.
948.
The chemical and trace-element features of the Late Cretaceous and Early Paleogene ignimbrite complexes of East Sikhote Alin are discussed. The Turonian-Campanian volcanic rocks of the Primorsky Complex compose linear structure of the Eastern Sikhote Alin volcanic belt. They are represented by crystalrich rhyolitic, rhyodacitic, and dacitic S-type plateau ignimbrites produced by fissure eruptions of acid magmas. The Maastrichtian-Paleocene volcanic rocks occur as isolated volcanic depression and caldera structures, which have no structural and spatial relations with the volcanic belt. This period is characterized by bimodal volcanism. The Samarginsky, Dorofeevsky, and Severyansky volcanic complexes are made up of basalt-andesite-dacite lavas and pyroclastic rocks, while the Levosobolevsky and Siyanovsky complexes are comprised of rhyolitic and dacitic tuffs and ignimbrites. Petrogeochemically, the felsic volcanic rocks are close to the S-type plateau ignimbrites of the Primorsky Complex. The Paleocene-Early Eocene silicic volcanics of the Bogopolsky Complex are represented by S- and A-type dacitic and rhyolitic tuffs and ignimbrites filling collapsed calderas. The eruption of A-type ferroan hyaloignimbrites occurred at the final stage of the Paleogene volcanism (Bogopolsky Complex). The magmatic rocks show well expressed mineralogical and geochemical evidence for the interaction between the crustal magmas and enriched sublithospheric mantle. It was shown that the revealed differences in the mineralogical and geochemical composition of the ignimbrite complexes are indicative of a change in the geodynamic regime of the Asian active continental margin at the Mesozoic-Cenozoic transition. 相似文献
949.
950.