Since their first discovery, predictions of the incidence of high temperature submarine vents has been made from along-axis surveys for the presence or absence of particle-rich “black smoker” hydrothermal plumes in the overlying water column. Recent work along intermediate and fast spreading ridges, however, has shown that abundant lower-temperature forms of seafloor fluid flow might be overlooked by this approach. Here, we report new data that allow us to test for both high- and low-temperature venting along the fast-spreading (110–132 mm/yr) equatorial East Pacific Rise (EPR), between 1.9°N and 4.9°S. We identify at least 32 discrete sites of hydrothermal activity, of which just 11 would have been resolved by particle-plume only survey methods. Such an approach would lead to a predicted frequency of high-temperature venting (F_s) along this section of the EPR of 4.2 sites/100 km, consistent with other particle-plume only surveys conducted under the auspices of InterRidge. When we include ORP sensor data to prospect for near-seafloor evidence of low-temperature venting, however, the calculated spatial frequency (Fs) for all styles of seafloor fluid flow increases by more than 3-fold, to Fs ≥ 15.5 sites/100 km. Hence, this study provides confirmation that low-temperature venting should be widespread along all fast-spreading mid-ocean ridges. While an appreciation of the importance of low-temperature axial venting to geophysical fluxes (heat, mass) is well established, our results reveal evidence for low-temperature fluid flow that is out of geochemical (redox) equilibrium with the overlying water column. Consequently, these fluxes may also play an important but previously overlooked role in global-scale ocean biogeochemical cycles.

自从他们的第一个发现以来，就通过沿轴向调查来确定上层水下水柱中是否存在富含颗粒的“黑烟”热液羽流，从而预测了高温海底通风孔的发生率。但是，最近在中间和快速扩散脊上的工作表明，这种方法可能会忽略大量低温形式的海底流体流动。在这里，我们报告了新的数据，这些数据使我们能够在1.9°N和4.9°S之间的快速扩展（110-132 mm / yr）赤道东太平洋上升（EPR）上测试高温和低温通风。我们确定了至少32个离散的水热活动点，其中只有11个可以通过仅颗粒状颗粒调查方法解决。这种方法将导致高温通风的预测频率（F_s）沿着EPR的这一部分为4.2个站点/ 100 km，这与InterRidge主持下进行的其他仅针对颗粒软垫的调查一致。但是，当我们将ORP传感器数据包括在近海底低温通风的证据中时，所有样式的海底流体流动的计算空间频率（Fs）都会增加3倍以上，达到Fs≥15.5个位点/ 100公里 因此，这项研究证实了低温通风应在所有快速扩散的中洋海脊中广泛传播。虽然人们已经充分认识到低温轴向通风对地球物理通量（热量，质量）的重要性，但我们的结果揭示了低温流体流动与上覆水柱处于地球化学（氧化还原）平衡之外的证据。因此，这些通量在全球规模的海洋生物地球化学循环中也可能起着重要但以前被忽视的作用。