Collaborative Research: Event response to an eruption at Axial Seamount

2015年4月24日，美国国家科学基金会资助的海洋天文台倡议(OOI)的电缆阵列探测到轴向海山可能发生喷发，预示着8000次小地震和火山口中心海底快速下沉2.4米。熔岩在火山口顶端或附近喷发的证据包括，OOI有线阵列上的仪器记录到的温度急剧上升--比事件发生后持续数周的环境高出0.6-0.7摄氏度。这次喷发很可能严重扰乱了峰顶破火山口内和周围的热液和生物系统，并提供了解决时间紧迫的科学问题的难得机会，这些问题只能通过近期的海底调查来调查。目前计划于2015年8月由NSF和NOAA资助的R/V Thompson号与ROV Jason和AUV Sentry一起前往轴海山号的邮轮为这样的反应提供了一个极好的机会。这项研究增加了3天的时间，以促进时间关键事件响应科学。使用船上多波束声纳和近底哨兵调查的详细海底测绘将覆盖预期喷发地点的火山口和邻近裂谷地带(S)。如果找到新的岩石，将使用210Po-210Pb技术进行采样和测年。热液羽流将通过CTD投射和传感器拖曳来识别。系泊设备将与微型自主羽流记录器一起部署，以测量温度、光衰减和氧化还原电位。海上团队计划向更广泛的科学界提供样本和数据，以便对海底过程进行有针对性的研究。

On 24 April 2015, the NSF-funded Ocean Observatories Initiative's (OOI) Cabled Array detected the onset of a probable eruption at Axial Seamount, heralded by a swarm of 8000 small earthquakes and a rapid subsidence of the seafloor by 2.4 meters at the center of the caldera. Evidence that lava was erupted in or near the summit caldera includes a dramatic temperature rise recorded by instruments on the OOI Cabled Array-- up to 0.6-0.7°C above ambient sustained for weeks after the event. This eruption is likely to have significantly perturbed the hydrothermal and biological systems in and around the summit caldera, and provides the rare opportunity to address time-critical scientific questions that can only be investigated with the near-term seafloor investigations. A currently scheduled NSF and NOAA funded cruise to Axial Seamount on R/V Thompson with ROV Jason and AUV Sentry in August 2015 provides an excellent opportunity for such a response. This study adds 3 days onto this cruise to facilitate time-critical event response science.Detailed seafloor mapping with shipboard multi-beam sonar and near-bottom Sentry surveys will cover areas of the caldera and adjacent rift zones that are expected eruption site(s). Fresh rock, if located, will be sampled and dated using the 210Po-210Pb technique. Hydrothermal plumes will be discerned with CTD casts and sensor tows. A mooring will be deployed with Miniature Autonomous Plume Recorders to measure temperature, light attenuation, and redox potential. The at-sea team plans to make samples and data available to the broader science community for targeted research on seafloor processes.