Collaborative Research: Event response to an eruption at Axial Seamount

合作研究：对轴向海山喷发的事件响应

• 批准号: 1546616
• 负责人: William Chadwick
• 金额: $ 1.86万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1546616&HistoricalAwards=false
• 关键词: Collaborative; Research; Event; response; eruption

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.

2015 年 4 月 24 日，美国国家科学基金会 (NSF) 资助的海洋观测计划 (OOI) 有线阵列探测到轴海山可能爆发喷发，预示着将发生 8000 次小地震，火山口中心的海底迅速下沉 2.4 米。熔岩在火山口山顶或其附近喷发的证据包括 OOI 电缆阵列上的仪器记录到的温度急剧上升——在事件发生后数周内持续比环境温度高出 0.6-0.7°C。这次喷发可能会严重扰乱山顶火山口及其周围的热液和生物系统，并为解决只能通过近期海底调查才能解决的时间紧迫的科学问题提供了难得的机会。目前计划于 2015 年 8 月由 NSF 和 NOAA 资助，乘坐 R/V Thompson 与 ROV Jason 和 AUV Sentry 前往 Axial Seamount 进行巡航，这为此类响应提供了绝佳的机会。这项研究将这次航行增加了 3 天，以促进时间紧迫的事件响应科学。利用船上多波束声纳和近海底哨兵勘测进行详细的海底测绘将覆盖预计喷发地点的破火山口和邻近裂谷带区域。如果找到新鲜岩石，将使用 210Po-210Pb 技术进行取样和测年。热液羽流将通过 CTD 铸件和传感器丝束来识别。系泊装置将部署微型自主羽流记录仪来测量温度、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。