Location Accuracy of the China National Seismograph Network Estimated by Repeating Events

INTRODUCTIONDigital seismological observation in China has had a significant development in recent years,especiallysince the last five years(Liu Ruifeng,et al.,2003).For further development,it isnecessarytoassessthe monitoringcapabilityof the existingseismological network.One of theimportantassessments is the estimation of regionalizedlocation accuracy.Upto present,several approaches have been proposed to assess the location accuracy,such asthe groundtruth event approach(e.g.,Lienert,199…     

The Statistical Analysis of Migration of Strong Earthquakes─Taking the North China Region as an Example

INTRODUCTIONMigrationofstrongearthquakesisaphenomenonwherebystrongearthquakestakeplaceinsuccessionincertainspatiallyregularpatterns (ZhangGuomin ,etal,2 0 0 1 ) .Seismologistsintheworldhavenoticedthisphenomenonforalongtime .Manyinstanceswerediscoveredinthepastdecades ,suchasthemigrationofstrongearthquakesalongtheNorthAnatolianFaultinTurkeysince1 939(Richter,1 958)andthemigrationofaseriesofearthquakes (MS ≥ 6 0 )aftertheMS7 9earthquakeinKwandong ,Japan (Utsu ,1 987) .Theexamplesofre…     

A review of: “The earth's core”

Abstract

by J. A. Jacobs, 1975, Academic Press, London, New York, San Francisco, U.S.A., viii + 253 pages.     

A review of: “The origin and evolution of galaxies”

Abstract

By B. J. T. Jones and J. E. Jones (Editors), D. Reidel, x + 358 pp. Dfl. 125, US$ 54.50 (ISBN 90 277 1507 6) 1983.     

A review of: “The earth's magnetic field”

Abstract

By Ronald T. Merrill and Michael W. McElhinny. Academic Press, 420 pp. Paperback: $30.00/£17.50 (UK only) ISBN: 0 12 491242 7 Hardback $67.50/$39.50 (UK only) ISBN: 0 12 491240 0 1983.     

A review of: “The physics of the earth's core: An introduction”

Abstract

By Paul Melchior. Pergamon Press, 1986. vi + 256 pp. $19.95 (ISBN 0080326064).     

A review of: “The earth's climate: Past and future” and “Theory of climate”

Abstract

The earth's climate: Past and future by M. I. Budyko. international geophysics series, Vol. 29, Academic Press, New York, London, x+307pp. £26.20, $39.50 (ISBN 0 12 139460 3) 1982.

Theory of climate by B. Saltzman. advances in geophysics, Vol. 25, Academic Press, New York, London, xiit505pp. £42.40, $64.00 (ISBN 0 12 018825 2) 1983.     

A review of: “The earth's variable rotation: Geophysical causes and consequences”

Abstract

By K. Lambeck (Cambridge Monograph on Mechanics and Applied Mathematics). Cambridge University Press, Cambridge, England, 1980. xi +449 pp. (Hard cover £35.00) (ISBN 0 521 22769 0).     

Modeling urban land use conversion of Daqing City,China: a comparative analysis of “top-down” and “bottom-up” approaches

During the past decades, Daqing City, China has experienced unprecedented urban expansion due to the rapid development of petroleum industry. With rapid urbanization and lack of strategic planning, Daqing is facing many socio-economic and environmental problems, and it is essential to examine the process of urbanization, and to develop policy recommendations for sustainable development. To address this problem, this paper examined the urbanization process of Daqing City through developing two multi-level models: an integrated system dynamic (SD) and CLUE-S model (SD-CLUES), and an integrated SD and stochastic cellular automata model (SD-CA). Analysis of results suggests that these two models generate significantly different results. With the SD-CLUES model, new urban developments are clustered in the downtown area or along major transportation networks, indicating exogenous driving forces playing an important role in shaping urban spatial dynamics. With the SD-CA model, on the contrary, the resultant new urban cells are spread over the entire study area, and associated with existing urban areas. Further, visual comparisons and validations indicate that the SD-CA model is a better alternative in explaining the urbanization mechanism of Daqing City. In addition, analysis of results suggests that the stochastic factor in the CA model has significant impact on the modeling accuracy.     

Micro-earthquakes “Just-underneath” Seismic Stations as Ground Truth Events——Application to the 2008 Wenchuan Aftershock Sequence

Analyzing the aftershock sequence of the 2008 Wenchuan earthquake, we considered 26 microearthquakes ＂just underneath＂ seismic stations. Making use of such special station-event configurations to determine the depth of these micro-earthquakes provided accurate relocation of aftershocks with a reference set of ＂ground truth （GT） events＂.     

The quiescence of earthquakes with M_L≥4.0 as an important precursory characteristic prior to strong shocks in North China region

Before a strong earthquake, there is often a process of quiescence or (absence( of regional seismic activity, which is a phenomenon that has attracted the attention of many scholars in China and other countries (LU, et al, 1985; Wesson, 1973). In the past ten-odd years, some Chinese seismologists made, earlier or later, special studies on the quiescence anomaly of seismicity in some specified areas from different angles. Taking the converted annual frequency of M=5.0 earthquakes in North Ch…     

A review of: “The earth: 1 the upper atmosphere,ionosphere and magnetosphere”

Abstract

Edited by Charlotte W. Gordon, V. Canuto and W. Ian Axford, Gordon and Breach Science Publishers, 412 pp., $63.00 ($35.00). (ISBN O 677 16100 X.) 1978.     

The sustainability of drinking water supply in rural China: Does the provision of drinking water investment mismatch the demand of residents?

It is doubted that the top down nature of investment planning may lead to mismatches between drinking water investment and the demands of local residents in rural China. Statistical and econometric analysis based on data of 2020 rural households from five Chinese provinces from 1998 to 2011 are used to illustrate the linkage between demand for drinking water investment and construction of drinking water projects. Household's demand significantly affects drinking water projects implemented by upper level governments and implemented jointly, but is not significant in explaining the projects implemented by village. There is evidence to suggest that the demands of local leaders override those of households in the implementation of drinking water projects provided by village in the early stage of 2005–2008. The situation improves in the latter stage of 2008–2011when the village level participatory bodies begin to provide opportunities for households to voice their preferences on public goods investment. The results of this study imply that it is important to explore appropriate regulations and policies that enabling local cadres to better meet local demands of their communities to ensure the sustainability of rural drinking water supply.     

A review of: “Energetics of the earth”

Abstract

By John Verhoogen. National Academy Press, 1980. 139 pp. ($9.00) (ISBN 0 309 03076 5) 1980.     

A review of: “Interiors of the planets”

Abstract

By A. H. Cook (Cambridge Planetary Sciences Series). University Press, Cambridge, 1980. xi + 348 pp. (£25.00) (ISBN 0 521 23214 7).     

Comment on the paper “The Centenary of solar-terrestrial physics”

Some additional data are given for the development of solar-terrestrial physics during the 19th and 20th centuries.