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，并且轴心海山中心的海底会迅速下沉 2.4 米。火山口顶部或附近喷发熔岩的证据包括火山口仪器记录的温度急剧上升。 OOI 电缆阵列——事件发生后数周内温度持续高于环境温度 0.6-0.7°C，这次喷发可能对山顶火山口及其周围的热液和生物系统产生了显着干扰，并提供了难得的机会来解决时间问题。关键的科学问题只能通过近期的海底调查来研究，目前计划由 NSF 和 NOAA 资助，于 8 月乘坐 R/V Thompson 与 ROV Jason 和 AUV Sentry 前往 Axial Seamount。 2015 年为此类响应提供了绝佳的机会。这项研究将这次航行延长了 3 天，以促进时间紧迫的事件响应科学。利用船载多波束声纳和近海底哨兵调查进行详细的海底测绘将覆盖破火山口和邻近地区。如果找到了预计喷发地点的裂谷区，将使用 210Po-210Pb 技术对新鲜岩石进行采样和测年。 CTD 铸件和传感器拖曳将与微型自主羽流记录仪一起部署，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，用于海底过程的有针对性的研究。 。