Seismic crustal structure beneath the BC convergent margin

BC汇聚边缘下方的地震地壳结构

• 批准号: 156159-2011
• 负责人: Spence, George
• 金额: $ 2.4万
• 依托单位: University of Victoria
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2011
• 资助国家: 加拿大
• 起止时间: 2011-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=476121
• 关键词: Seismic; crustal; structure; beneath; BC

The interface between the underthrust oceanic plate and over-riding continental plate is currently locked and accumulating energy which will be released in a future great earthquake similar to the magnitude 9 event in 1700. However, we do not know whether the earthquake will rupture the seafloor and contribute to tsunami generation. At present, there is a lack of information as basic as whether there are even any small earthquakes in the region offshore Vancouver Island. Such information is critical to provide the scientific basis for informing the public of earthquake, tsunami and seafloor-landslide hazards, and may help prevent the potential loss of life. In collaboration with researchers at the Geological Survey of Canada and seismologists at the Japan Agency for Marine-Earth Science & Technology (JAMSTEC), I deployed 33 ocean bottom seismometers (OBSs) from JAMSTEC for a 3-month period in summer 2010. As well, 10 broadband OBSs from Woods Hole Oceanographic Institution (currently deployed for 1-year period) plus 2 near-real-time NEPTUNE-Canada broadband instruments form part of our grid. Phase 2 of the project is planned in 2012, with ~35 Japanese OBSs to be deployed in a more focused study. We anticipate that these deployments will allow us to detect earthquakes at an unprecedented sensitivity. The broadband instruments will also allow us to record "Very Low Frequency Earthquakes", slow-slip events often associated with low-amplitude seismic tremor.

逆冲海洋板块和上覆大陆板块之间的界面目前被锁定并积聚能量，这些能量将在未来类似1700年9级事件的大地震中释放。然而，我们不知道这次地震是否会导致海底破裂并导致海啸的产生。目前，连温哥华岛近海地区是否发生小地震等基本信息都缺乏。此类信息对于向公众通报地震、海啸和海底滑坡灾害提供科学依据至关重要，并可能有助于防止潜在的生命损失。 2010 年夏季，我与加拿大地质调查局的研究人员和日本海洋地球科学技术机构 (JAMSTEC) 的地震学家合作，在为期 3 个月的时间内部署了 JAMSTEC 的 33 个海底地震仪 (OBS)。此外，伍兹霍尔海洋研究所的 10 个宽带 OBS（目前部署时间为 1 年）加上 2 个近实时的 NEPTUNE-Canada 宽带仪器成为我们的一部分 网格。该项目的第二阶段计划于 2012 年进行，在一项更有针对性的研究中部署约 35 个日本 OBS。我们预计这些部署将使我们能够以前所未有的灵敏度检测地震。宽带仪器还将使我们能够记录“甚低频地震”，即通常与低振幅地震颤动相关的慢滑事件。