地震活动因子A值及其在华北地震中短期预报中的应用

综合考虑了地震活动时空强３ 个方面的震兆特征,定义了地震活动因子 Ａ值．使用１９７２ ～１９９６ 年华北地区地震资料进行空间扫描,研究中强以上地震前 Ａ 值的中短期异常变化特征．结果表明,在中短期阶段大多数地震前出现的 Ａ 值中期异常区面积明显缩小或消失,也有一些地震前１ ～３ 个月 Ａ 值异常区面积再次增大．还就用 Ａ 值进行地震中短期预报的有关问题进行了讨论     

北纬35°线附近上地幔软流圈活动格局与地震的关系

北纬３５°线是一条地震特发带,上地幔软流圈对流方向恰好在该线附近发生 转换,研究结果表明,北纬３５°线附近上地幔软流圈活动格局与地震密切相关.     

华北北部6级地震前后的地电阻率变化

研究了河北张北等３次６级地震前后地电异常的变化及特征。结果表明,６级地震的地电前兆能显示出０．５ａ左右的趋势异常变化,但台项少,强度弱,分布零散,远不及７级强震前的异常显著。发现个别地震前地电正常年变化形态发生了明显变化,完全破坏了原年变规律,出现了可辨认的异常变化。认为用地电方法在目前实现中强地震的准确预报是比较困难的     

Impact of the North Atlantic Oscillation on streamflow in Western Iran

The Middle East region, where arid and semi‐arid regions occupy most of the land, is extremely vulnerable to any natural or anthropogenic reductions in available water resources. Much of the observed interannual‐decadal variability in Middle Eastern streamflow is physically linked to a large‐scale atmospheric circulation patterns such as the North Atlantic Oscillation (NAO). In this work, the relationship between the NAO index and the seasonal and annual streamflows in the west of Iran was statistically examined during the last four decades. The correlations were constructed for two scenarios (with and without time lag). The associations between the annual and seasonal streamflows and the simultaneous NAO index were found to be poor and insignificant. The possibility of streamflow forecasting was also explored, and the results of lag correlations revealed that streamflow responses at the NAO signal with two and three seasons delays. The highest Spearman correlation coefficient of 0.379 was found between the spring NAO index and the autumn streamflow series at Taghsimab station, indicating that roughly 14% of the variance in the streamflow series is associated with NAO forcing. Copyright © 2013 John Wiley & Sons, Ltd.     

对朝鲜2006年、2009年和2013年3次地下核试验的相对定位

采用双差定位方法, 对朝鲜2006年、2009年和2013年的3次核试验进行相对定位.根据19个区域地震台和8个远震台的垂直分量波形资料, 计算了多种震相(P波、S波和LR波等)的互相关时差, 并由测量时差反演两两核爆的相对空间位置, 通过随机生成部分台站组合进行扰动实验以估算定位的不确定度.结果表明, 相对于朝鲜2009年核试验, 2013年核试验位于其南257 m、西385 m, 2006年核试验位于其南503 m、东2589 m.当扰动实验中随机选取的台站数目为20个时, 在95%置信度下, 朝鲜2013年和2006年核试验相对于2009年核试验的地表定位结果的不确定度约为150 m.     

Sensitivity of the surface temperature to changes in total solar irradiance calculated with the WRF model

The temperature sensitivity of the WRF model to changes in Total Solar Irradiance (TSI). The simulations were performed for a region centered over the North Atlantic Ocean, including portions of Eastern North America, Western Europe and Northwest Africa. Four simulations were run with different TSI values. Also, a fifth simulation was performed in which we varied the initial atmospheric conditions, in order to compare the effect on the temperature of both, changes in the TSI and initial atmospheric conditions. Comparing temperature monthly averages we found that changes in TSI and in the initial conditions have a measurable impact on temperature in the region of study. The sensitivity of the model using non-dimensional parameters was also estimated. The numerical experiments show some features that might allow to distinguish between the effects on the temperature due to changes in TSI from those caused by initial conditions. However, TSI changes are of the same order of magnitude than those of disturbances in the initial conditions. We also found that the mean monthly values of temperature over the full grid, did not present significant variations due to changes of either initial conditions or TSI.     

Nitrogen and carbon cycling in the North Sea and exchange with the North Atlantic—A model study. Part I. Nitrogen budget and fluxes

The three-dimensional biogeochemical model ECOHAM was applied to the Northwest European Shelf (47°41′–63°53′N, 15°5′W–13°55′E) for the years 1993–1996. Nitrogen budgets were calculated for the years 1995 and 1996 for the inner shelf region, the North Sea (511,725 km²). Simulated temperatures as well as nitrate, oxygen, and chlorophyll concentrations are compared with observations.     

华北成组强震孕育过程及预测研究

利用华北丰富的历史地震资料, 通过研究地震与块体活动的联系, 揭示了地震高潮期的形成过程。 认为地震高潮期成组强震的孕育与区域块体的运动方式相联系。 一个地震活动期可分为二个阶段, 在前期块体边界的运动是很不平衡的, 各组地震主要是由于各局部范围若干闭锁段破裂和破裂间相互作用的结果, 当沿块体边界的破裂发展到一定程度时, 这些边界所围的地块就会进入以整体运动为主的阶段, 这时块体边界的运动具有一定程度的同步性, 加之闭锁段破裂后不再重新闭锁, 从而导致块体边界闭锁段由弱到强渐进式的破裂过程, 直至一组强闭锁段完成破裂, 形成地震活动高潮。 这是成组强震形成的根本原因, 另外强震间的诱发作用也是强震成组发生的重要原因。 最后概述了如何利用以上模式预测地震高潮期的时间、 强度和主体活动场所。     

华北活动地块区南缘阜南-霍邱地区地壳活动习性初探

阜南-霍邱地区地处华北和华南活动地块区边缘构造带，通过对其进行地震地质调查和综合分析研究，发现晚更新世以来该区存在强度较弱的构造变形现象，即：小震沿着主要断裂呈线性条带状分布；研究区南部及断裂近侧的上更新统中发育共轭剪节理；1970年代，研究区固始、霍邱和阜南等地陆续发生过长度不一、宽窄不等、方向不同的地裂缝，展布与肥中断裂或王老人集断裂近乎一致。本文认为，研究区局部小震丛集、上更新统中赋存共轭剪节理、裂面充填物显微揉皱变形和现代地裂缝的生成等现象，反映出地壳能量被缓慢释放和相应断裂发生微弱活动；研究区曾发生过一次破坏性地震(江口集Ms43/4地震)。综上所述，研究区地壳晚第四纪以来具有微弱活动性，且主要表现为蠕滑活动方式。     

Buruanga peninsula and Antique Range: Two contrasting terranes in Northwest Panay,Philippines featuring an arc–continent collision zone

Alternating chert–clastic sequences juxtaposed with limestone blocks, which are units typical of accretionary complexes, constitute the Buruanga peninsula. New lithostratigraphic units are proposed in this study: the Unidos Formation (Jurassic chert sequence), the Saboncogon Formation (Jurassic siliceous mudstone–terrigenous mudstone and quartz‐rich sandstone), the Gibon Formation (Jurassic(?) bedded pelagic limestone), the Libertad Metamorphics (Jurassic–Cretaceous slate, phyllite, and schist) and the Buruanga Formation (Pliocene–Pleistocene reefal limestone). The first three sedimentary sequences in the Buruanga peninsula show close affinity with the ocean plate stratigraphy of the North Palawan terrane in Busuanga Island: Lower–Middle Jurassic chert sequences overlain by Middle–Upper Jurassic clastics, juxtaposed with pelagic limestone. Moreover, the JR5–JR6 (Callovian to Oxfordian) siliceous mudstone of the Saboncogon Formation in the Buruanga peninsula correlates with the JR5–JR6 siliceous mudstone of the Guinlo Formation in the Middle Busuanga Belt. These findings suggest that the Buruanga peninsula may be part of the North Palawan terrane. The rocks of the Buruanga peninsula completely differ from the Middle Miocene basaltic to andesitic pyroclastic and lava flow deposits with reefal limestone and arkosic sandstone of the Antique Range. Thus, the previously suggested boundary between the Palawan microcontinental block and the Philippine Mobile Belt in the central Philippines, which is the suture zone between the Buruanga peninsula and the Antique Range, is confirmed. This boundary is similarly considered as the collision zone between them.