【摘要】 本文主要研究活动断裂带附近地下水中的氢同位素变化与地震的相关性。2009年1月初,我们在汶川地震的发震断裂带——龙门山断裂带南缘的雅安进行考察,并开始采集地热深井的地下水样品,到5月初结束。在采样期间,龙门山断裂带发生4～5级余震多次。对所采地下水样品氢同位素δD值的分析结果表明,发震断裂带附近地下水中的氢同位素异常与该断裂带上4.0级以上地震有一定相关性。从氢同位素δD值随时间变化曲线可看出,(1)震前氢同位素δD值由背景值逐渐降低,震后升高,然后再逐渐回归背景值;(2)地震的级别越大,氢同位素δD值变化越显著;(3)从氢同位素δD值开始系统地降低到地震发生,这个过程大约可持续一周左右时间,属于临震预报的时间范畴。从本研究结果可得出地下水中氢同位素δD值异常能够反映断裂带的地震活动性,可作为5.0级以上地震临震预测的一种方法。更多还原

【Abstract】 In this paper,we studied the hydrogen isotope changes in underground water associated with the active faults.After the Wenchuan Earthquake on 12th May,2008,the geothermal samples were collected from the deep well in the Ya’an area which is at the southern edge of the Longmengshan Fault,from the beginning of Jan.,2009 to middle of May,2009.During this period,there were several aftershocks of Ms 4.0~5.0.We analyzed the hydrogen isotope of the samples. From the hydrogen isotope changes with time it can be seen,(1) hydrogen isotope value δD decreased gradually from the background before the earthquake,increased after the earthquake,and then gradually returned to background; (2) the greater the level of the earthquake,the more hydrogen isotope δD value changes; (3) the process of hydrogen isotope value reduction to the earthquake occurrence takes about one week or so,which falls into the impending earthquake prediction time.The results can be drawn from this study that hydrogen isotope in underground water reflects the abnormal seismic activity,therefore,can be used for imminent earthquake prediction over Ms 5.0.更多还原