Geophysics

地震是全球最危险的地质灾害。为了更有弹性地应对它们，至关重要的是要识别导致故障的原因，并确定故障发生的频率和程度。我提出的研究计划旨在更好地了解不列颠哥伦比亚省及其周边地区的活动断层和地震行为，使用地震大地测量学（地震期间和地震之间地球如何变形）和构造地貌学（地球表面地形如何在许多地震周期中演变）领域的新的创新测量方法。有三个相互关联的项目要素：(i)利用温哥华岛近海的首次海底大地测量，我们将调查卡斯卡迪亚北部巨型逆冲断层的震间锁止程度，这被广泛认为是卡斯卡迪亚构造学中悬而未决的问题之一。我们假设，巨型逆冲断层的浅层部分缓慢而无声地蠕动，这表明在下一次大地震中断裂到海沟的可能性很低。如果得到证实，就不需要为2011年在日本东部观测到的那种规模的地震和海啸做计划了。（ii）利用陆地上大量新的遥感光探测和测距（激光雷达）数据，我们将识别和描述北美板块内的地壳断层：从西部的温哥华岛到东部的落基山脉，从北部的育空地区到南部的美国边境。这些断层产生的地震比海上巨型逆冲断层要小，但它们离人口中心和关键基础设施更近，（在当地）可能更具破坏性。我们在全省范围内对机载激光雷达数据的系统研究，以及我们部署的最先进的激光雷达无人机进行精细断层测绘，都是第一次。（iii）准确的地震预报依赖于对地震和断层机制的理解，包括控制破裂成核、传播、停止和复发的因素。研究全球大陆地震破裂，利用新兴的大地测量学和地震学成像技术，我们将测试一套假设，这些假设将地震行为的关键方面——其中许多直接影响地面震动的分布和强度——与主断层长期滑动历史（或“结构成熟度”）的简单指标联系起来。

Earthquakes are the most dangerous geological hazards globally. To become more resilient to them, it is vital to identify the causative faults and determine the frequencies and magnitudes at which they fail. My proposed research program seeks a better understanding of active faulting and earthquake behaviour within and surrounding British Columbia using new and innovative measurements from the fields of earthquake geodesy (how the Earth deforms during and between earthquakes) and tectonic geomorphology (how Earth's surface topography evolves over many earthquake cycles).There are three interrelated program elements:(i) Using the first ever sea-floor geodetic measurements from offshore Vancouver Island, we will investigate the degree of interseismic locking on the the northern Cascadia megathrust, widely recognized as one of the outstanding questions in Cascadia tectonics. We hypothesize that the shallow part of the megathrust creeps slowly and silently, which would indicate a low likelihood for rupture to the trench in the next great earthquake. If confirmed, there would be less need for planning for an earthquake and tsunami of the size observed in eastern Japan in 2011.(ii) By taking advantage of a wealth of new remotely-sensed light detection and ranging (lidar) data on land, we will identify and characterize crustal faulting within the North America plate: from Vancouver Island in the west to the Rocky Mountains in the east and from Yukon in the north to the U.S. border in the south. These faults generate smaller earthquakes than the offshore megathrust, but are located much closer to population centres and critical infrastructure and could (locally) be even more damaging. Our systematic study of airborne lidar data at the scale of the province and our deployment of a state-of-the-art lidar drone for fine-scale fault mapping are both firsts.(iii) Accurate earthquake forecasts rely upon understanding the mechanics of earthquakes and faulting, including the factors that govern rupture nucleation, propagation, arrest, and recurrence. Working on continental earthquake ruptures globally and drawing upon emerging geodetic and seismological imaging techniques, we will test a suite of hypotheses that relate critical aspects of earthquake behaviour - many of which directly influence the distribution and intensity of ground shaking - to simple metrics for the long-term history of slip (or "structural maturity") of the host fault.