Johnson HP, Hutnak M, Dziak RP, Fox CG, Urcuyo I, Cowen JP, Nabelek J, Fisher C
School of Oceanography, University of Washington, Seattle 98195-7940, USA.
Nature. 2000 Sep 14;407(6801):174-7. doi: 10.1038/35025040.
Hydrothermal vents on mid-ocean ridges of the northeast Pacific Ocean are known to respond to seismic disturbances, with observed changes in vent temperature. But these disturbances resulted from submarine volcanic activity; until now, there have been no observations of the response of a vent system to non-magmatic, tectonic events. Here we report measurements of hydrothermal vent temperature from several vents on the Juan de Fuca ridge in June 1999, before, during and after an earthquake swarm of apparent tectonic origin. Vent fluid temperatures began to rise 4-11 days after the first earthquake. Following this initial increase, the vent temperatures oscillated for about a month before settling down to higher values. We also observed a tenfold increase in fluid output from the hydrothermal system over a period of at least 80 days, extending along the entire ridge segment. Such a large, segment-wide thermal response to relatively modest tectonic activity is surprising, and raises questions about the sources of excess heat and fluid, and the possible effect on vent biological communities.
众所周知，东北太平洋大洋中脊上的热液喷口会对地震扰动做出反应，喷口温度会出现明显变化。但这些扰动是由海底火山活动引起的；到目前为止，尚未观察到喷口系统对非岩浆构造事件的反应。在此，我们报告了1999年6月在胡安德富卡洋脊上几个喷口处进行的热液喷口温度测量结果，测量时间涵盖了一次明显源于构造活动的地震群发生之前、期间和之后。在第一次地震发生后的4至11天，喷口流体温度开始上升。在最初的温度升高之后，喷口温度振荡了大约一个月，然后才稳定在较高的值。我们还观察到，在至少80天的时间里，热液系统的流体排放量增加了10倍，且这种增加沿着整个洋脊段延伸。对相对适度的构造活动出现如此大规模、全段范围的热响应令人惊讶，并引发了关于多余热量和流体来源以及对喷口生物群落可能影响的问题。
