Seismogenic zone processes of Hikurangi subduction, New Zealand: illumination using the SAHKE seismic project

大地震和海啸发生在苏门答腊、日本、秘鲁-智利和卡斯卡迪亚等俯冲带。前三个地点是最近发生地震的地点，而第三个地点预计将在未来的某个时候在美国西北海岸发生大地震。新西兰北岛附近的Hikurangi俯冲系统表现出一系列的滑动条件，从地震到强耦合，伴随着同震、慢滑和重复的微地震事件的应变释放，但它没有发生过8级以上的大地震，要么是因为这里的条件不支持这样的事件，要么更有可能是因为自19世纪中叶欧洲人到达那里以来没有发生过大地震。因此，了解Hikurangi俯冲系统的地震活动性具有重要的社会意义。多学科研究表明，上下板块构造、俯冲沉积、热效应、区域构造应力场和流体压力等因素的复杂相互作用控制着Hikurangi造震带的存在和分布。本研究对Hikurangi系统南部进行了全面的地震学研究，目的是表征其强耦合的发震带及其向地震慢滑区转变的下倾。除了其明显的社会相关性外，本研究的更广泛影响还包括对来自美国、新西兰和日本的研究生的跨国试验，以及对本科生的研究经验。

Great earthquakes and tsunamis occur at subduction zones such as Sumatra, Japan, Peru-Chile, and Cascadia. The first three localities have been sites of recent events, while the third is expected to produce a great earthquake along the northwest coast of the U.S. at some time in the furture. The Hikurangi subduction system off North Island, New Zealand exhibits a range of slip conditions, from aseismic to strongly coupled, with strain release by coseismic, slow slip, and repeating microseismic events, but it has not been the site of a great M8+ earthquake, either because conditions here do not support such an event, or, more likely, because no large event has occurred since Europeans arrived there in the mid 19th century. Consequently, understanding seismicity in the Hikurangi subduction system is a matter of considerable societal relevance. Multi-disciplinary studies reveal the complex interplay between upper and lower plate structure, subducting sediment, thermal effects, regional tectonic stress regime, and fluid pressures to control the presence and distribution of the Hikurangi seismogenic zones. This study comprises a comprehensive seismological study of the southern Hikurangi system with the aim of characterizing its strongly coupled seismogenic zone and its downdip transition into an aseismic slow slip regime. In additional to its obvious societal relvance, the broader impacts of this study include cross-natioanl trianig of graduate students from the U.S., New Zealand and Japan, and a research experience for undergraduates.