试论体视学方法在地球科学中的某些应用

本文论述了体视学的科学含义和方法的某些特征。体视学是定量研究人体或生物器官、材料、介质或物体三维组织结构的科学分支：其广泛的含义可以理解为：由天空对象的低维信息和数据,用以获取研究对象的高维（三维或更高）性质或图像特征,包括它们所涉及的定量参数之间的数学关系,并中以应用的一门交叉性科学分支。根据当前科学的发展水平,例举出体视学方法在地球科学中有以下几方面的应用：（１）在监测火山岩浆囊活动中的作用;     

2001年发生厄尔尼诺事件的天文条件

据 2 0 0 1年 8月 2 3日《长春晚报》报道 ,最近上海天文台预测 ,厄尔尼诺事件将在今年年末发生 .笔者在1999年就曾预报 2 0 0 0～ 2 0 0 1年将发生厄尔尼诺事件 ,并在 2 0 0 1年进一步预测其发生时间在 2 0 0 1年末[1～ 3 ] .当太阳、地球和月球大致成一线 ,月球处于近地点 ,地球处于春分、秋分或近日点 ,地球扁率发生最大变化 ,是发生厄尔尼诺事件的天文条件 .行星冲日 ,亦称为特殊天象组合期 ,地球自转异常减慢[2～ 8] ,会对厄尔尼诺事件的发生起强化作用 .关于潮汐对地球气候影响的研究在近年来取得了令人瞩目的成果 .地壳、地幔排液排…     

黑龙江镜泊湖火山地区电性结构初步研究

在黑龙江镜泊湖火山地区做了 30个点的大地电磁测深工作。结果表明 :测区为非一维结构 ,中部为二维结构 ,走向为北东向。上下大致可分为 3个电性层 ,电阻率上部为中阻 ,中部为高阻 ,下部为低阻。测区四周电阻率高 ,中部有一个截面不规则的北东向拉长的低阻立式柱状体 ,该柱体的电阻率从上到下也呈“中 -高 -低”形式     

核工程选址中的火山调查与评价——以吉林省为例

火山活动是核电厂选址中无法回避的重要课题。吉林省新生代以来火山活动极为强烈,特别是第四纪和现代火山活动更为突出,据吉林省火山分布与喷发活动特点,分析了火山与地震活动、火山与构造活动、火山与深部环境的关系,以及火山类型与性质、火山危险性预测和灾害评估。在上述讨论的基础上,提出了在核电厂选址工作中有关火山调查和评价方法的建议     

对1991—1992年厄尔尼诺事件形成的一种看法

本文对１９９１－１９９２年厄尔尼诺事件前兆及形成过程进行了分析，与１９８２－１９８３年和１９８６－１９８７年厄尔尼诺事件进行了对比。对自西向东传播的厄尔尼诺事件的形成特点及传播规律进行了解释。     

Results of repeated leveling surveys at Newberry Volcano, Oregon, and near Lassen Peak Volcano, California

 Personnel from the U.S. Geological Survey's Cascades Volcano Observatory conducted first-order, class-II leveling surveys near Lassen Peak, California, in 1991 and at Newberry Volcano, Oregon, in 1985, 1986, and 1994. Near Lassen Peak no significant vertical displacements had occurred along either of two traverses, 33 and 44 km long, since second-order surveys in 1932 and 1934. At Newberry, however, the 1994 survey suggests that the volcano's summit area had risen as much as 97±22 mm with respect to a third-order survey in 1931. The 1931 and 1994 surveys measured a 37-km-long, east–west traverse across the entire volcano. The 1985 and 1986 surveys, on the other hand, measured only a 9-km-long traverse across the summit caldera with only one benchmark in common with the 1931 survey. Comparison of the 1985, 1986, and 1994 surveys revealed no significant differential displacements inside the caldera. A possible mechanism for uplift during 1931–1994 is injection of approximately 0.06 km³ of magma at a depth of approximately 10 km beneath the volcano's summit. The average magma supply rate of approximately 1×10^–3 km³/year would be generally consistent with the volcano's growth rate averaged over its 600,000-year history (0.7–1.7×10^–3 km³/year). Received: 10 September 1998 / Accepted: 4 December 1998     

Elementary analysis of data from Tianchi Volcano

Tianchi Volcano is the largest potential erupticve volcano in China. Analyzing these data on seismic monitoring, deformation observation and water chemistry investigation gained from the Tianchi Volcano Observatory (TVO), the authors consider that the Tianchi Volcano is in going into a new flourishing time.     

Lyttelton Volcano, Banks Peninsula, New Zealand: Primary volcanic landforms and eruptive centre identification

Lyttelton Volcano, Banks Peninsula, New Zealand, has historically been viewed as a simple volcanic cone. This paper uses digital terrain models (DTM) and primary volcanic landforms to reinterpret Lyttelton Volcano as having multiple eruptive centres. Primary volcanic landforms are features produced during active volcanism, classified as constructional, hypabyssal, and erosional volcanic features. Constructional volcanic features are lava flows, scoria cones and domes; hypabyssal volcanic features are dykes and sills; and erosional volcanic features are valley and ridge patterns and orientations. Lava flow trends are recognised from aerial photograph analysis and supported by field observations, highlighting radiating lava trends around specific locations within Lyttelton Harbour. Scoria cones and domes occur on the outer flanks of volcanic cones, and are used as such in the identification of remnant cone surfaces. Dyke orientations are plotted and then projected to the interior of the volcano, defining 13 zones of convergence. The projected arrays of these orientations highlight defined regions along the erosional crater rim, each indicating a radial dyke swarm, from which the projected trends of the associated dykes indicate an eruptive centre. Valley and ridge orientations are projected from the longest valley or ridge segment, towards the inner harbour. Radiating erosive patterns are incepted during the growth and degradation of a volcanic cone, with the resulting trends orienting to the summit. Zones of convergence/eruptive centres are identified from lava flow orientations, onlapping lava sequences, scoria cones, and intrusive locations. The summit of a volcanic edifice can be identified from the orientations of valleys and ridges, while radial dyke systems determine whether this summit was a volcanic centre or simply a local topographic high. Volcanic landforms are used to identify cone sectors, the preserved sector associated with a particular eruptive centre. Cone sector limits are defined by a basal footprint and an erosional crater rim, with similar arcuate features (remnant cone features) being exposed in the interior of the volcano. Lyttelton Volcano comprises fifteen volcanic cones, with vent locations controlled by underlying fault lineaments. The growth and erosion of each volcanic cone is reflected in primary volcanic landforms, with the preserved features of cones confined to cone sectors and cone artefacts.     

长白山天池火山研究区地壳三维界面与速度分布联合成像

迅速发展并得到广泛应用的空间深地震测深技术通过采用三维数据采集的观测系统,利用三维层析技术,以求获得区域地壳三维分层结构和三维速度分布图像。它与传统的二维宽角反射－折射剖面技术相结合,可以有效地研究区域性地壳结构,特别是壳内深断裂和低速层的空间展布特征。Kanasewich等(1985)给出了利用空间深地震测深资料重建地壳三维界面的方法,我们在其方法的基础之上,进一步提出地壳三维界面和速度分布联合反演的方法。正问题的计算是在Chander(1977)关于三维平界面的快速两点追踪算法上的改进,在获得界面三维反演结果的基础之上,利用剩余走时残差,采用模型不分块反演技术(Tarantola,Nercession 1986)重建地壳三维速度图像。 1998年国家地震局地球物理勘探中心在长白山火山区实施了三维深地震测深观测,目的是研究天池火山的岩浆系统。利用本次实验所获得的780余个PmP波走时数据,采用上述的方法重建了研究区莫霍界面和地壳三维速度分布图像。研究结果表明,本区莫霍界面由北东方向向南逐渐加深,在天池火山口下达最深,并且被一些可能存在的地壳厚度陡变带(或深断裂)所切割。在东西方向莫霍面由西向东缓缓加深,其变化较南北方向缓和。特别值得注意的是,存在着一条近北东方向的莫霍面深度陡变带(或深断裂带)从天池火山口西部穿过,相应位置与马鞍山—三道白河地堑型断裂相一致,该断裂带可能对天山火山喷发时岩浆的运移起到重要作用。深度为15km和25km的P波速度图像表明,在天池火山口下分布着近南北走向明显的低P波速度分布,其南北方向延伸的范围约为80－90公里左右。比较这两个深度上的低P波速度体的分布特点,可以看出这个低P波速度体尺度随深度逐渐变小,但在25km深度处仍清晰可见,这表明该区岩浆自上地幔侵入地壳的“痕迹”,这也意味着,长白山天池火山的岩浆系统极有可能延伸到上地幔或更深一些。