加拿利区域的热点

以 ДВЕрошенко为首的俄罗斯科学院海洋研究所大西洋分部的专家们 ,审查了有关加拿利群岛、马德拉岛和佛得角群岛是由于上升地幔流在热点区活动而产生的假说。对这个假说有利的证据是 ,在加拿利群岛上火山岩的年龄由西向东随着远离强烈的火山活动区而增加。但是认为这只是一种趋向 ,还带有很大的不确定性 ,再加上群岛不是位于同一海岭上 ,还有在非洲沿岸未发现年龄更为古老的同类岩石。地幔流在其上部运动的板块上留下了火山形成物的痕迹。它们呈东西向弧状延伸 ,并不进入大陆。科学家们研究了深海钻探计划和大洋钻探计划报告中有…     

俯冲时的地震振动

在地壳中除一般的地震外 ,还可能发生其他不那么快速的地震过程。例如 ,在火山附近常记录到相当持续的振动 ,被称之为火山的抖动。2 0 0 0年日本开始起动由安置在全国各地、深度为 2 0 0～ 3 0 0m钻孔中的由 60 0台数字地震仪组成的“Hi 网络”。按仪器的灵敏度及其分布的密度 ,它超过了世界上所有其他类似的网络。“Hi 网络”记录到发生在南海俯冲区范围内地壳下层延续数分钟至数星期的振动。日本地震学家ObaraK成功地记录到离火山活动中心非常远的地壳振动。如果没有“Hi 网络”和在集中处理过程中所收集的资料 ,这些振动也许未被注意到…     

Geochemistry of recent hydrothermal systems of Mendeleev Volcano （Kuril Islands） and surrounding waters

On the Kuril Islands there are 85 volcanoes, 39 of which are active. Hot springs and mud pots are wide spread in this area and have significant inputs on the chemical composition of the surrounding surface waters and environment. We present results of trace elements as well as data on H, O, S, and He isotope ratios for hydrothermal systems of the Mendeleev Volcano （Kunashir Island） and surrounding surface waters. Water and gas samples were taken from springs and holes as well as creeks and the Lesnaya River. Among the thermal water types, three main groups can be distinguished. The first group includes the waters, in which SO4^- ion predominant. The water temperature on the surface reaches 97℃, and TDS varies from a few g/L to 7 g/L. These waters are acid to superacid with pH values ranging 0.6 to 2.3. The second group is sodium-chloride waters. A maximum TDS is 14.2 g/L. The waters are neutral or alkaline; pH varies from 6.9 to 8.2. The third group is the sodium-chloride-sulfate-bicarbonate water. The Stolbovskie springs, located in the periphery of the Mendeleev Volcano are representative of this type. The pH of these waters is close to neutral. TDS is 1.9 g/L. They are rather the derivatives of sodium-chloride waters arisen from dilution of them by subsurface waters. The Kuslyi Creek and Lesnaya River are located near the Mendeleev Volcano. The most acid springs discharge into the Kislyi Creek as a result pH of this creek being 2.5, and contents of most elements rather high. For example, the contents of dissolved solids of Si, Fe, Al, Mn, Zn, in waters of the Kislaya Creek are 22.1, 8.1, 6.2, 1.29, and 0.28 mg/L, and correspondently. The water of the Lesnaya River, （Before the Kislyi Creek, pH is about 8 with TDS 102 mg/L, but after the Kuslyi Creek, pH decreases and the concentrations of chemical elements increase. Debit of the Kislayi Creek in summer season is about 370 L/sec. It means that every day only this small creek inputs in the Lesnay River about 706 kg of Si;     

“地震与火山”公开课后的启示

在波澜起伏的教改浪潮中，我尝试开设了“地震与火山”这堂公开课。在备课过程中查寻整理资料、制作修改课件、设计创立课堂流程，自然化了不少心思，然而作为教师的我，在这一过程中所学到的远不止课程本身或其所涉及到的相关领域知识、能力。几次“模拟演习”师生都能按事先设计好的环节逐一展开，当时我感到自然、流畅、顺利，然而在有众多领导、专家、教师在场的公开课堂上，学生、课堂带给我的却是另外一种东西，那是一种感动、一种启示，甚至是一种震撼。课后我及时与学生交流沟通，我想用字表达一下几个方面的感想与启示。