主应变比异常理论在青海祁连地震预报中的应用

本文利用主应变比异常理论分析了祁连建站以来地应变观测资料，认为肃南──祁连断裂段上及附近发生的地震是由于构造应力场的变化，在引张应力状态下，正断层或走滑断层易于活动而导致的。     

新疆钻孔应变异常特征及其与地震三要素关系研究

将新疆高精度钻孔应变仪１０年来观测到的应变异常划分为趋势异常、短期异常、临震异常三类，并对这三种异常的特征进行了分析总结．认为，地震三要素与应变异常参量关系密切，震级与异常量级、震中距有着确定性关系。     

均匀半空间条件下水平细柱体不均匀介质影响场的定量研究

采用边界元数值计算法解决地电阻率（ρ＿ｓ）法中不均匀介质细柱体对ρ＿Ｓ测值影响的定量计算问题，给出细柱体自身参数变化，（电阻率、长度）、柱体与观测装置相对位置的变化（方向和位置）以及观测装置尺度改变时影响场的定量计算结果和影响特征。计算结果可供条件相当的台站使用。     

新疆新源台固体潮潮汐因子特征浅析

采用Venedikov调和分析方法对新源台倾斜固体潮整点观测数据进行处理，得到倾斜固体潮鸩波潮汐因子变化曲线。分析其震兆异常特征，给出了新源台倾斜固体潮潮汐因子异常标准，结果发现异常与周围200km范围内的5级以上地震对应较好，具有较高的预报效能并通过了尺值评分检验。     

青藏高原腹地现今地应力测量与应力状态研究

青藏高原腹地现今构造活动强烈，为了解强烈构造活动下的应力背景，我们在五道梁、风火山、雁石坪和安多不同构造部位的四个测点采用压磁应力解除法进行了现场应力实测工作，测量深度12～20m.测量结果表明, 最大主应力方向总体为北东向，与地质、地震以及大地测量等方面的研究成果基本吻合；最大主应力量值为36～68MPa（安多测点除外），与其他地区测量结果相比，属于中等偏高；安多测点最大主应力方向为北西西向，最大主应力量值为81MPa，与其他测点有较大差别，反映了板块缝合带附近现今应力状态的复杂性.     

Identification of buried sinkholes using refraction tomography at Ft. Campbell Army Airfield,Kentucky

Karst aquifers are highly susceptible to contamination, with numerous points of entry for contaminants through recharge features such as sinkholes, swallow holes and solutionally enlarged fractures. These recharge features may be filled or obscured at the surface, requiring the use of geophysical or remote sensing techniques for their identification. This study uses seismic refraction data collected at the Ft. Campbell Army Airfield (CAAF), Kentucky, USA, to test the hypothesis that refraction tomography is a useful tool for imaging bedrock depressions beneath thick overburden (greater than 20 m of unconsolidated sediment). Southeast of the main taxiway of CAAF seismic velocity tomograms imaged a bedrock low, possibly a closed depression, at a depth of 25 m that had been earlier identified through delay-time analysis of the same refraction data. Tomography suggests the bedrock low is about 250-m wide by 10-m deep at its widest point. High rates of contaminant vapor extraction over the western extension of this feature suggest a high concentration of contaminants above, and within, this filled bedrock low, the base of which may contain solutionally enlarged fractures (i.e. karst conduits) that could funnel these contaminants to the upper or lower bedrock aquifers. This study thus demonstrates the viability of seismic refraction tomography as a tool for identification of filled sinkholes and bedrock depressions in karst areas.     

Late Quaternary paleoenvironments of an ephemeral wetland in North Dakota,USA: relative interactions of ground-water hydrology and climate change

This study of fossils (pollen, plant macrofossils, stomata and fish) and sediments (lithostratigraphy and geochemistry) from the Wendel site in North Dakota, USA, emphasizes the importance of considering ground-water hydrology when deciphering paleoclimate signals from lakes in postglacial landscapes. The Wendel site was a paleolake from about 11,500 ¹⁴C yr BP to 11,100 ¹⁴C yr BP. Afterwards, the lake-level lowered until it became a prairie marsh by 9,300 ¹⁴C yr BP and finally, at 8,500 ¹⁴C yr BP, an ephemeral wetland as it is today. Meanwhile, the vegetation changed from a white spruce parkland (11,500 to 10,500 ¹⁴C yr BP) to deciduous parkland, followed by grassland at 9,300 ¹⁴C yr BP. The pattern and timing of these aquatic and terrestrial changes are similar to coeval kettle lake records from adjacent uplands, providing a regional aridity signal. However, two local sources of ground water were identified from the fossil and geochemical data, which mediated atmospheric inputs to the Wendel basin. First, the paleolake received water from the melting of stagnant ice buried under local till for about 900 years after glacier recession. Later, Holocene droughts probably caused the lower-elevation Wendel site to capture the ground water of up-gradient lakes.     

The November 2002 eruption at Piton de la Fournaise volcano,La Réunion Island: ground deformation,seismicity, and pit crater collapse

An eruption on the eastern flank of Piton de la Fournaise volcano started on 16 November, 2002 after 10 months of quiescence. After a relatively constant level of activity during the first 13 days of the eruption, lava discharge, volcanic tremor and seismicity increased from 29 November to 3 December. Lava effusion suddenly ceased on 3 December while shallow earthquakes beneath the Dolomieu summit crater were still recorded at a rate of about one per minute. This unusual activity continued and increased in intensity over the next three weeks, ending with the formation of a pit crater within Dolomieu. Based on ground deformation, measured by rapid-static and continuous GPS and an extensometer, seismic data, and lava effusion patterns, the eruptive period is divided into five stages: 1) slow summit inflation and sporadic seismicity; 2) rapid summit inflation and a short seismic crisis; 3) rapid flank inflation, onset of summit deflation, sporadic seismicity, accompanied by stable effusion; 4) flank inflation, coupled with summit deflation, intense seismicity, and increased lava effusion; and finally 5) little deflation, intense shallow seismicity, and the end of lava effusion. We propose a model in which the pre-intrusive inflation of Stage 1 in the months preceding the eruption was caused by a magma body located near sea level. The magma reservoir was the source of an intrusion rising under the summit during Stage 2. In Stage 3, the magma ponded at a shallow level in the edifice while the lateral injection of a radial dike reached the surface on the eastern flank of the basaltic volcano, causing lava effusion. Pressure decrease in the magmatic plumbing system followed, resulting in upward migration of a collapse front, forming a subterranean column of debris by faulting and stoping. This caused intense shallow seismicity, increase in discharge of lava and volcanic tremor at the lateral vent in Stage 4 and, eventually the formation of a pit crater in Stage 5.     

江苏省锡山市西部地区地下水资源计算模型研究

从地下水运动均衡原理的角度分析江苏省锡山市西部地区第Ⅱ承压含水层天然和现状开采条件下的地下水均衡要素.揭示了该区地下水开采与地面沉降的关系,其中现状开采条件下的75%～80%的开采量来自于粘性土层的压密水量.根据地面沉降的发生机理剖析地面沉降严重发育地区忽略地面沉降影响因子建立的地下水资源计算模型中存在的问题针对存在的问题,提出了地下水可开采资源合理的计算方法,并对融有地面沉降影响因子的地下水资源计算模型的可实现性进行了分析.     

山西榆次地裂缝形变微动态的观测与研究

通过对山西榆次地裂缝及墙体裂缝的动态监测，发现如下特征：地裂缝总体趋势为增大，年速率小于等于1mm/a。东部地裂缝带地裂平均速率为0．6mm/a，且大于西部地裂缝带，地裂有向东南方向（榆次市区）扩展的态势；从曲线形态看，无论是地面测点还是建筑物上的测点，都不同程度地受气温变化和降水的干扰。裂缝与温度的变化呈负相关，与降水的变化呈正相关。从地裂的分布形状、区域形变场特征及新构造运动的角度看，附近的断裂活动与地裂的发展似有一定的关系。