共查询到20条相似文献,搜索用时 46 毫秒
1.
StaticsolutionofacrackdegeneratedfromdynamicsolutionofapropagatingcrackShi-YuLI(李世愚)andYun-TaiCHEN(陈运泰)(InstituteofGeophysics... 相似文献
2.
TÓMAS JÓHANNESSON 《水文科学杂志》2013,58(3):417-434
Abstract Observations from the jökulhlaup from Grímsvötn in Vatnajökull, south-eastern Iceland, in 1996 indicate that the jökulhlaup was initiated by the movement of a localised pressure wave that travelled 50 km in 10 h from Grimsvötn to the terminus, forming a subglacial pathway along the glacier bed. Shortly after this wave reached the terminus, the jökulhlaup was flowing at a high discharge through a tunnel that would have needed much longer time to form by ice melting as assumed in existing theories of jökulhlaups. Frozen sediments formed in crevasses and frazil ice on the surface of the flood waters indicate the flow of supercooled water in the terminus region, demonstrating that the rate of heat transfer from subglacial flood water to the overlying ice is greatly underestimated in current theories. 相似文献
3.
J. E. Geisler 《地球物理与天体物理流体动力学》2013,107(1-2):249-272
Abstract This paper describes the linear response of an inviscid two‐layer model of a deep ocean on an f‐plane to a hurricane translating across the surface at constant speed. The forcing is a localized, radially‐symmetric pattern of positive wind stress curl and negative pressure anomaly. Only the steady state response is considered. The principal result is the identification of an internal wake in the lee of the storm, present when the translation speed of the storm exceeds the baroclinic long wave speed. The amplitude of the wake depends on the length of time over which the stress is experienced at a given point. The angle of the wedge filled by the wake is small, an effect due to the fact that the scale of a hurricane is typically larger than the baroclinic radius of deformation. After the wake disperses, a geostrophically balanced baroclinic ridge remains along the storm track. 相似文献
4.
Sharing the results of a high-resolution ocean general circulation model under a multi-discipline framework—a review of OFES activities 总被引:1,自引:0,他引:1
Yukio Masumoto 《Ocean Dynamics》2010,60(3):633-652
Quasi-global, eddy-resolving ocean general circulation model experiments, so-called OFES (ocean general circulation model
for the Earth Simulator) project, have been conducted with a basic concept of sharing results among scientists in a multi-discipline
framework. Studies using such OFES results extend widely from the physical aspects of ocean circulations and energy considerations
to biogeochemical tracer distributions and marine ecosystem dynamics. This article reviews the OFES activities during a period
from 2004 to 2009 and highlights some interesting scientific results that emerged from the OFES project. Future plans of the
project are also presented. 相似文献
5.
A method of estimation of occurrence probability of earthquake intensity at a given site from the results of a ten-year scale of earthquake prediction described with a probability of occurrence in a given "prediction cell" is proposed in this paper. 2316 cities and towns in China were analyzed by using this method. The probability of intensity Ⅵ-Ⅸ were given for every city. These results can be used for the earthquake insurance, loss estimation, and planning of disaster protection. 相似文献
6.
Monika B. Kalinowska Paweł M. Rowiński Janusz Kubrak Dorota Mirosław-Świątek 《Acta Geophysica》2012,60(1):214-231
The problem of two-dimensional mathematical modelling of heated cooling water discharges into running waters is considered
in the paper. Two models — one for the evaluation of 2D turbulent velocity field and the other, developed by authors of the
study, for 2D heat transport in open-channels — were used in the calculations. Relevant scenarios of the spread of heated
water discharged from a designed gas-stem power plant to be constructed at the Vistula River were presented. Environmentally
most friendly variant of the discharge of the thermal pollution was selected from among four various variants. 相似文献
7.
《Acta Geochimica》2017,(3)
With the development of hydropower in the karst area of Southwest China, a series of cascade canyon reservoirs have been formed through the construction of dams. Given that hydrodynamic conditions in canyon reservoirs play a pivotal role in controlling the spatiotemporal distribution of physical and chemical properties of the stored water, hydrodynamic characteristics are of great importance in understanding biogeochemical cycles in those reservoirs. To further this understanding, a field campaign was conducted in the Wujiangdu Reservoir of Guizhou Province. It was found that from the reservoir inlet to the front of the dam, velocity(v) was negativelycorrelated and had a logarithmic relationship with distance along the ship track(s) under dry-season flow conditions[v =-0.104 ln(s) + 0.4756]. Analysis showed that dryseason flow velocity had no significant correlation with water temperature, p H, or dissolved oxygen(DO). However, when velocity decreased to 0.061 m/s, water depth increased abruptly. In addition, DO displayed a sudden drop and the trend in p H changed from increasing to decreasing, while water temperature showed an opposite trend, indicating the existence of a transition zone from the river to the reservoir. 相似文献
8.
Features of a rare advection-radiation fog event 总被引:3,自引:0,他引:3
To investigate effects of atmospheric pollutants on fog nature, a comprehensive in situ observation project was implemented in the northern suburb of Nanjing, in December of 2006. For December 24-27 there occurred a heavy fog lasting 4 d in succession. This event is of rare characteristics, namely long persistence, high concentration, tall fog top, acid fog water and explosive growth. Detailed analysis along with the causes of the fog was presented. The evidence suggests that the fog was generated by nighttime radiative cooling, maintained and developed under effects of warm, wet advection. As a result, it is an advection-radiation fog event. 相似文献
9.
We discuss various asymptotic regimes of kinematic nonlinear -dynamos in a thin differentially rotating shell as well as conditions for the applicability of the corresponding asymptotic solutions. 相似文献
10.
Studyofa3DseismicgapYUANQINGZHU1)(朱元清)CONGJUNXIA1)(夏从俊)GETUZUOLI2)(左力格图)HUIMINLI1)(李慧民)1)SeismologicalBureauofShanghai,... 相似文献
11.
Evaluation of Earthquake Losses and Establishment of a Corresponding Database System 总被引:1,自引:0,他引:1
After the Datong-Yanggao earthquake (October 1989),a special team was organized for the first time by the SSB of China to start the work of earthquake damage evaluation for the purpose of providing the government with a scientific basis for disaster relief.The result of the evaluation played an important role in speeding up rehabilitation and reducing damage losses in the earthquake area.Based on the evaluation of earthquake damage from the Datong-Yanggao earthquake and recent research results,this paper presents a method for quick evaluation of earthquake damages,introduces software entitled EDEP (earthquake damage evaluation program) for evaluating earthquake damage,and cites a case to explain the main function and application of the EDEP.Finally,for a quicker evaluation of earthquake damages,the paper also proposes the establishment of database systems of earthquake damage evaluation in the emphatically monitored areas and ways to build up such database systems. 相似文献
12.
Fuchs R Dupouy C Douillet P Caillaud M Mangin A Pinazo C 《Marine pollution bulletin》2012,64(8):1596-1613
In view of increasing environmental awareness and biodiversity conservation, understanding the main forcing mechanism driving biogeochemical cycles in coral reefs and lagoon coastal areas is a priority. La Ni?a events cause unbalanced situations in the Equatorial Pacific and result in enhanced precipitation in South West Pacific coastal areas. We investigated the impact of heavy rainfalls during the 2008 La Ni?a event on the New Caledonia lagoon using a 3D coupled on-line hydrodynamic-biogeochemical model. Simulations and data showed that the whole lagoon was impacted by river inputs and stronger hydrodynamics, enhancing chlorophyll-a concentration by a factor between 1.7 and 1.9. The coupled model provided new insights into plume transport, highlighting that eastern plumes can be advected northwards or can reach the South West Lagoon, depending on the balance between regional, tide-induced, and wind-induced surface currents. It also provided a synoptic view of lagoon biogeochemical-hydrodynamic response, when remote sensing data are not available due to cloud coverage. 相似文献
13.
The problem of point injection of charged particles into a magnetic dipole field was considered. Analytical expressions were obtained by the Störmer method for regions of allowed pulses of charged particles at random points of a dipole field at a set position of the point source of particles. It was found that, for a fixed location of the studied point, there was a specific structure of the coordinate space in the form of a set of seven regions, where the injector location in each region corresponded to a definite form of an allowed pulse region at the studied point. It was shown that the allowed region boundaries in four of the mentioned regions were surfaces of conic section revolution. 相似文献
14.
Based on the solutions of the Green’s function for a saturated porous medium obtained by the authors,and using transformation of axisymmetric coordinates,Sommerfeld integrals and superposition of the influence field on a free surface,the authors have obtained displacement solutions of a saturated porous medium subjected to a torsional force in a half-space.The relationship curves of the displacement solutions and various parameters(permeability,frequency,etc.)under action of a unit of torque are also given in this paper.The results are consistent with previous Reissner’s solutions,where a two-phase medium decays to a single-phase medium.The solution is useful in solving relevant dynamic problems of a twophase saturated medium in engineering. 相似文献
15.
Andrea Cortis Carlos E. Puente Huai-Hsien Huang Mahesh L. Maskey Bellie Sivakumar Nelson Obregón 《Stochastic Environmental Research and Risk Assessment (SERRA)》2014,28(6):1421-1429
In this study, we attempt to offer a solid physical basis for the deterministic fractal–multifractal (FM) approach in geophysics (Puente, Phys Let A 161:441–447, 1992; J Hydrol 187:65–80, 1996). We show how the geometric construction of derived measures, as Platonic projections of fractal interpolating functions transforming multinomial multifractal measures, naturally defines a non-trivial cascade process that may be interpreted as a particular realization of a random multiplicative cascade. In such a light, we argue that the FM approach is as “physical” as any other phenomenological approach based on Richardson’s eddies splitting, which indeed lead to well-accepted models of the intermittencies of nature, as it happens, for instance, when rainfall is interpreted as a quasi-passive tracer in a turbulent flow. Although neither a fractal interpolating function nor the specific multipliers of a random multiplicative cascade can be measured physically, we show how a fractal transformation “cuts through” plausible scenarios to produce a suitable realization that reflects specific arrangements of energies (masses) as seen in nature. This explains why the FM approach properly captures the spectrum of singularities and other statistical features of given data sets. As the FM approach faithfully encodes data sets with compression ratios typically exceeding 100:1, such a property further enhances its “physical simplicity.” We also provide a connection between the FM approach and advection–diffusion processes. 相似文献
16.
Different variants for interpreting the data of vertical and horizontal channels of GPS measurements are examined during experimental works. The movements of an observation point are imitated experimentally in the vertical and horizontal directions at a geophysical observatory. The experiments are carried out on a pedestal with original benchmarks in both directions. The movements are imitated in the high-frequency range with different time values of movement from one point to another, which did not exceed 1 h. The errors in imaging movements of measurement points according to the results of interpreting the readings of GPS receivers are shown in relation to the benchmark movements of measurement points in the vertical and horizontal directions. These data are processed in the differential mode using the precise point positioning (PPP) method. The experimental results confirm that there is no potential of imaging vertical movements of the Earth’s surface caused by tidal observations according to GPS receiver data. 相似文献
17.
姚清林 《地震学报(英文版)》1995,8(1):135-142
TheresearchofasolutiononlocatingoptimallyastationforseismicdisastersrescueinacityQing-LinYAO(姚清林)(InstituteofGeology,StateSei... 相似文献
18.
Application of a time-magnitude prediction model for earthquakes 总被引:1,自引:0,他引:1
In this paper we discuss the physical meaning of the magnitude-time model parameters for earthquake prediction. The gestation process for strong earthquake in all eleven seismic zones in China can be described by the magnitude-time prediction model using the computations of the parameters of the model. The average model parameter values for China are: b = 0.383, c=0.154, d = 0.035, B = 0.844, C = -0.209, and D = 0.188. The robustness of the model parameters is estimated from the variation in the minimum magnitude of the transformed data, the spatial extent, and the temporal period. Analysis of the spatial and temporal suitability of the model indicates that the computation unit size should be at least 4°× 4°for seismic zones in North China, at least 3° × 3° in Southwest and Northwest China, and the time period should be as long as possible. 相似文献
19.
Location of Tibetan earthquakes──a nonlinear approach by a simplex optimized technique 总被引:1,自引:0,他引:1
Location of Tibetan earthquakes──a nonlinear approach by a simplex optimized technique(赵珠)(丁志峰)(易桂喜/)(王建格)LocationofTibetanea... 相似文献
20.
N. S. Shilova 《Geomagnetism and Aeronomy》2008,48(6):709-712
The duration of elementary eruption process and intervals between them for flares of different importance have been determined based on the photometric data for flares, observed by a TRACE spacecraft at a wavelength of 195 Å. It has been revealed that the values of these parameters increase with increasing flare importance. It is assumed that the appearance of elementary nonstationary flare centers correlates with the origination of solitons at self-organized criticality. 相似文献