Walsh F Rall, Zoback Mark D
Department of Geophysics, Stanford University, Stanford, CA 94305, USA.
Sci Adv. 2015 Jun 18;1(5):e1500195. doi: 10.1126/sciadv.1500195. eCollection 2015 Jun.
Over the past 5 years, parts of Oklahoma have experienced marked increases in the number of small- to moderate-sized earthquakes. In three study areas that encompass the vast majority of the recent seismicity, we show that the increases in seismicity follow 5- to 10-fold increases in the rates of saltwater disposal. Adjacent areas where there has been relatively little saltwater disposal have had comparatively few recent earthquakes. In the areas of seismic activity, the saltwater disposal principally comes from "produced" water, saline pore water that is coproduced with oil and then injected into deeper sedimentary formations. These formations appear to be in hydraulic communication with potentially active faults in crystalline basement, where nearly all the earthquakes are occurring. Although most of the recent earthquakes have posed little danger to the public, the possibility of triggering damaging earthquakes on potentially active basement faults cannot be discounted.
在过去5年里，俄克拉荷马州的部分地区经历了中小规模地震数量的显著增加。在涵盖了近期绝大多数地震活动的三个研究区域，我们发现地震活动的增加与盐水处置率5至10倍的增长同步。盐水处置相对较少的相邻地区近期地震则相对较少。在地震活动区域，盐水处置主要来自“产出”水，即与石油共生然后注入更深沉积层的含盐孔隙水。这些地层似乎与结晶基底中潜在的活动断层存在水力联系，而几乎所有地震都发生在结晶基底。尽管近期大多数地震对公众造成的危险较小，但在潜在活动的基底断层上引发破坏性地震的可能性不能忽视。
