Seismogenic Origin of the Ancient Avdat Ruins,Negev Desert,Israel

The present communication addresses the potential use of damage features, observed in the ancient ruins of the Avdat archeological site (Negev Desert, Israel) as a tool to identify the seismic origin of the destruction there and roughly to determine the direction of seismic wave propagation. This revised version was published online in June 2006 with corrections to the Cover Date.     

Inference and Assumption in Historical Seismology

The principal aim in studies of historical earthquakes is usually to be able to derive parameters for past earthquakes from macroseismic or other data and thus extend back in time parametric earthquake catalogues, often with improved seismic hazard studies as the ultimate goal. In cases of relatively recent historical earthquakes, for example, those of the 18th and 19th centuries, it is often the case that there is such an abundance of available macroseismic data that estimating earthquake parameters is relatively straightforward. For earlier historical periods, especially medieval and earlier, and also for areas where settlement or documentation are sparse, the situation is much harder. The seismologist often finds that he has only a few data points (or even one) for an earthquake that nevertheless appears to be regionally significant.In such cases, it is natural that the investigator will attempt to make the most of the available data, expanding it by making working assumptions, and from these deriving conclusions by inference (i.e. the process of proceeding logically from some premise). This can be seen in a number of existing studies; in some cases extremely slight data are so magnified by the use of inference that one must regard the results as tentative in the extreme. Two main types of inference can be distinguished. The first type is inference from documentation. This is where assumptions are made such as: the absence of a report of the earthquake from this monastic chronicle indicates that at this locality the earthquake was not felt. The second type is inference from seismicity. Here one deals with arguments such as all recent earthquakes felt at town X are events occurring in seismic zone Y, therefore this ancient earthquake which is only reported at town X probably also occurred in this zone.While in many cases such assumptions may very well be correct, they are usually not testable – or at least untested. Furthermore, it is possible to produce numerous contrary examples. It is concluded that the use of inference to amplify poor data must be made very transparent to the end user of the results, to avoid misleading appearances of accuracy. In many cases it may be best to abandon the quest for parameters altogether and admit that the data are inadequate.     

Potential control of climatic changes on flood events in the Yangtze Delta during 1100-2002

1IntroductionClimatic warming, flood hazards and their impacts on human society receive increasing attention from governments and public (IPCC, 2001). During recent years, agriculture, industry and even the development of the whole national economy suffered tremendous loss resulted from flood and waterlogging hazards.The Yangtze Delta is densely populated and economically developed. Monsoonal climate, geomorphologic characteristics and human activities inflict floods and water-logging hazar…     

Relationship between earthquake and volcanic eruption inferred from historical records

Introduction From the records of Wudalianchi volcanic group eruption in 1720~1721 obtained from the Man ethnic group files of Heilongjiang General Yamen in Qing Dynasty (WU, 1998; CHEN, WU, 2003), we have discovered the eruption time, state, material and scale of Laoheishan and Hu-oshaoshan volcanoes, as well as numerous seismic records. These historical materials are discov-ered for the first time although the study on Wudalianchi volcanic group has a long history. These earthquakes co…     

Research in historical earthquakes in the Korean peninsula and its circumferential regions

The historical earthquake data is one of the important foundations for seismic monitoring, earthquake fore-cast and seismic safety evaluation. However, the recognition of earthquake is limited by the scientific and techno-logical level. Therefore, the earthquake can only be described using perfect earthquake catalogue after the seismo-graph is invented. Before this time, the earthquake parameters were determined according to the earthquake disas-ter on the surface and the written records in history, and the earthquake level was measured using earthquake in-tensity.     

山西断陷带太原-临汾部分的强地震平均复发间隔与未来危险段落研究

1303年山西洪洞M8大地震距今已700年. 为了分析长期地震危险性，本文将山西断陷带太原——临汾部分划分为5个震源段，根据历史地震和GPS观测资料，估算出各段的平均地震矩率与强地震平均复发间隔，进而根据最近30多年的台网地震资料计算获得的b值图象，分析不同段落现今应力积累的相对水平. 主要结果表明:临汾盆地段的平均地震矩率为2.211016~3.031016Nm/a, M7.5地震的平均复发间隔估值为1 560~2 140 a. 灵石——洪洞段M8地震的平均复发间隔估值在4300~5100 a之间, 相当于平均矩率为2.581016~3.101016Nm/a. b值图象显示灵石——洪洞段与临汾盆地段现今处于低或较低的应力水平，可能反映自1303年M8和1695年M7.5大地震破裂后，这两段的断面强度至今仍未恢复. 候马段和介休——汾阳段具有相对较高的应力水平，并结合平均复发间隔估值，判定这两个段落可能是未来强震的潜在危险段.      

从历史记录看地震与火山喷发关系

史料记载表明，五大连池火山1720~1721年喷发期间有大量地震活动.本文从描述这些地震活动的文字记录入手，并结合国际火山地震研究的新成果，探讨了地震类型及地震与火山喷发关系，指出震群是火山喷发的重要前兆指标，强调火山地震的监测对火山喷发预报的意义.      

On the recording characteristics of the original Wiechert seismographs at Göttingen (Germany)

The mechanical, automatically recording seismological instruments developed by Emil Wiechert in Göttingen at the beginning of the 20th century are still in use today. I comparethe recording characteristics of these seismographswith a modern, electrodynamic MARK L4-3D instrument. The frequency-dependent transfer functions are determined and used to restitute the`true' ground displacement. The displacement waveforms at the different instruments are well correlated at frequencies between 0.05 and 4.0 Hz.Amplitudes differ by a factor of less than two. This is sufficientfor the determination of seismological magnitudes which are defined on a logarithmicbasis. The timing accuracy is less favourable due to theslow recording speed on the smoked paper. However, relativetime differences within one second may be resolved, allowing the use of variousmodern seismological interpretation techniques.     

Completeness Analysis of the Historical Earthquake Catalogue in China

The historical earthquake catalogue of China has lasted more than 3000 years,and most of its data are inferred from historical records.The earthquake catalogue in earlier times is not complete owing to various reasons,so some events are lost.This paper estimates the loss rate of earthquakes with various magnitudes in the historical earthquake catalogue for different time intervals quantitatively by using the Gutenberg-Richter formula and modern instrumental records,which will provide the references for statistic research in seismicity.     

利用多时次资料的EOF迭代温度长期预报

考虑多时次历史资料，基于ＥＯＦ迭代方案，将观测事实与统计方法结合，建立预报因子与预报对象的联系，开展长期预报试验。对四川盆地夏季温度的预报表明：这种容纳多时次资料、基于ＥＯＦ迭代的物理－统计预报方法是一种有效的长期预报途径。