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Determination of streaming potential coefficients in various physical and chemical conditions to quantitatively estimate interstitial fluid's flow from tempral and spatial self-potential variations on Miyakejima island

确定各种物理和化学条件下的流动势系数，以根据三宅岛的时间和空间自势变化定量估计间质液的流动

基本信息

批准号：
14540390
负责人：
UYESHIMA Makoto
金额：
$ 1.86万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14540390/
关键词：
streaming potential coefficient room experiment self potential Miyakejima island

项目摘要

We determined zeta-potential in various physical and chemical conditions by room experiment to quantitatively evaluate interstitial fluid's flow from temporal and spatial self-potential variations in association with Miyakejima 2000 summit eruption. In the first year, we designed and prepared necessary apparatus and collected rock samples on Miyakejima and Kozushima islands. Since we found that the topographic effect on Kozushima island is about 10mV/m (10mV decrease pre 1m altitude change), which is 10 times larger than that on Miyakejima island (1mV/m), measurement and comparison of zeta-potentials for the rock samples in both islands become another target of this study. Mikyakejima and Kozushima islands are composed of basalts and rhyolites, respectively.Main results are as follows:(1)p dependence of zeta-potential for Miyakejima rocks was determined by using interstitial fluids of HCl-KCl-KOH composition. Zeta-potential values in pH 3-10 range from -10 to -20 mV, whose absolute value is 10 times smaller than Ishido & Mizutani (1981)'s results, which were regarded as representative zeta-potential values. In the higher pH conditions, zeta-potential absolute value gets larger and becomes similar to their results.(2)For both islands' rocks, pH dependence of zeta-potential in pH>3 range is almost the same. In the smaller pH range, zeta-potential absolute value of Miyakejima rocks is getting smaler, becomes zero at about pH 2 and changed to be positive in further acid condition, whereas that of Kozushima rocks shows no such significant variation and remains negative.(3)For results with the finer rock samples, the larger zeta-potential absolute value is obtained.

通过室内实验测定了不同物理化学条件下的ζ电位，从时空自电位变化定量评价了与2000年宫古岛火山喷发相关的间隙流体流动。第一年，我们设计并准备了必要的仪器，并在三宅岛和小竹岛采集了岩石样本。由于我们发现小竹岛的地形效应约为10mV/m（海拔变化1m前降低10mV），是三宅岛（1mV/m）的10倍，因此测量和比较两岛岩石样品的ζ电位成为本研究的另一个目标。三宅岛和小竹岛分别由玄武岩和流纹岩组成。主要结果如下：(1)利用HCl-KCl-KOH组成的间质流体确定了三宅岛岩石ζ电位的p依赖性。pH值3-10的ζ电位值范围为-10 ~ -20 mV，其绝对值比Ishido & Mizutani（1981）的结果小10倍，被认为是具有代表性的ζ电位值。在较高的pH条件下，ζ电位绝对值变得更大，并变得与它们的结果相似。(2)两岛岩石在pH bbbb3范围内ζ电位的pH依赖性基本相同。在较小的pH范围内，三宅岛岩石的ζ电位绝对值越来越小，在pH 2左右变为零，在进一步的酸性条件下变为正，而小竹岛岩石的ζ电位绝对值变化不明显，仍然为负。(3)岩样越细，ζ电位绝对值越大。