Illuminating the seismogenic zones of large, hazardous faults with seismic arrays

地球的构造板块在地壳中称为断层的裂隙处相互移动。断层以不同的方式移动-一些断层缓慢蠕动，而另一些断层被锁定，直到它们在灾难性的地震中突然移动。我们现在明白，断层不是离散的平面，而是几米到几公里宽的形变带。实验室和数值模型告诉我们，断裂带的结构和性质控制着断层的运动方式，包括控制地震的大小、速度、深度和方向--所有这些因素都决定了断层运动造成的破坏程度。因此，为了了解地震发生的地点和方式，以及它们的破裂形式可能是什么，我们必须更好地识别断裂带结构和对地震孕育行为的控制。在断裂带上部署地震台阵是在断裂带内部“看到”的最好方法。地震技术和计算能力的进步现在使在偏远地区部署密集地震阵列成为可能。我将使用地震阵列来研究很少被研究但具有全球意义的断层，这些断层为地震科学中的紧迫问题提供了答案。为什么在突如其来的地震中，有些断层会持续蠕动，而另一些则会滑动？为什么只有一小部分有记录的地震以超切变速度破裂，而地面震动相应增加？巨大的空间(和时间)温度变化如何影响与活火山共存的断层的破裂？解决这些问题对于我们减轻地震危险和更好地理解断层和地震的物理学的能力至关重要。

Earth's tectonic plates move past each other at cracks in Earth's crust called faults. Faults move in diverse ways - some faults slowly creep, while others are locked until they suddenly move in catastrophic earthquakes. We now understand that faults are not discrete planes but are zones of deformation, metres to kilometres wide. Laboratory and numerical models tell us that the structure and properties of fault zones control how a fault moves, including governing the size, speed, depth and direction of earthquakes - all factors that determine how much damage results from fault motion. To understand where and how earthquakes occur, and what their rupture styles are likely to be, we therefore have to better discern fault zone structure and controls on seismogenic behaviour.The best way to 'see' inside faults is by deploying seismic arrays above them. Advances in seismic technology and computing power now make deploying dense seismic arrays in remote areas feasible. I will use seismic arrays to investigate rarely studied but globally significant faults that offer answers to pressing questions in earthquake science. Why do some faults continuously creep whereas others slip in sudden earthquakes? Why do only a small proportion of recorded earthquakes rupture at supershear speeds, with a corresponding increase in ground shaking? How do large spatial (and temporal) temperature variations influence the rupture of faults that are co-located with active volcanoes? Addressing these questions is critical to our ability to mitigate seismic hazard and better understand the physics of faulting and earthquakes.