RAPID: Deploying a dense network to record seismicity at the Rattlesnake Ridge landslide

2017年10月，在华盛顿州亚基马以南的响尾蛇岭上发现了一系列裂缝。 当时，它们大约有1米深。 截至2017年12月下旬，仅仅两个月后，这些裂缝已经发展到超过80米深。 这些裂缝代表了响尾蛇岭滑坡的侧缘，估计有400万立方米的物质正在缓慢地下山。 缓慢移动的岩体位于（弱）沉积岩层之上，沉积岩层位于较厚的哥伦比亚河泛滥玄武岩层之间。 最好的情况（也是最有可能的情况）是这种物质继续缓慢地向南移动，落入一个沥青采石场。 然而，另一种（不太可能的）情况涉及灾难性的故障，可能会阻塞82号公路，并大坝的亚基马河淹没周围地区。 这一快速建议的目的是在周围地区部署40个节点地震仪，以持续监测来自滑坡的地震信号。节点地震仪（或节点）是小型、轻型、无电缆、三分量地震仪。 这种最先进的技术是为石油和天然气勘探开发的，但是节点也可以用于研究各种其他地震过程，例如地震和滑坡。 单个传感器的大小和（相对）低的成本允许容易部署的密集观测网络产生高质量的数据。 由此产生的数据集可用于确定来自滑坡的地震信号的位置、时间和性质。 与滑坡相关的地震活动的空间和时间演变可以用来更好地描述滑坡的特征，并可能预测何时可能发生故障。将在华盛顿州亚基马附近的Rattlesnake Ridge滑坡周围部署40个节点地震仪。 这些仪器将每30天进行一次“热交换”，直到滑坡失效或滑坡达到稳定状态。 这些部署将产生三个分量的地震数据，根据这些数据将计算旅行时间，以形成潜在震源的3D网格。网络波束形成方法将遵循检测，定位和表征地震信号来自滑坡。 这些信息将提供新的见解的大小和性质的幻灯片的岩石块以及程度的内部变形。该项目具有潜在的广泛社会影响，将有助于量化和了解滑坡过程。

In October of 2017, a series of cracks were discovered on Rattlesnake Ridge south of Yakima, WA. At that time, they were ~1 m deep. As of late December 2017, just two months later, those same cracks had grown to over 80 m deep. These cracks represent the lateral margin of the Rattlesnake Ridge landslide, which consists of an estimated 4 million cubic meters of material that is making its way downhill slowly. The slowly moving rock mass sits atop a (weak) sedimentary rock layer between thicker layers of Columbia River flood basalt. The best case (and most likely scenario) is that this material continues to move south slowly and fall into an asphalt quarry. However, an alternative (unlikely) scenario involves catastrophic failure which could block Highway 82, and dam the Yakima River flooding the surrounding area. The objective of this RAPID proposal is to deploy 40 nodal seismometers in the surrounding area to continuously monitor seismic signals coming from the slide. Nodal seismometers (or nodes) are small, lightweight, cable free, three-component seismometers. This state-of-the-art technology was developed for oil and gas exploration, however, nodes can also be used to study a variety of other seismic processes, such as earthquakes and landslides. The size and (relatively) low cost of individual sensors allows for easily deployable, dense observation networks that produce high-quality data. The resulting dataset can be used to determine the location, timing and nature of seismic signals coming from the slide. The spatial and temporal evolution of slide related seismicity can be used to better characterize the landslide and potentially to predict when failure may occur.Forty nodal seismometers will be deployed around the Rattlesnake Ridge landslide near Yakima, WA. These instruments will be "hot swapped" every 30 days until the landslide fails or until the landslide reaches steady-state. These deployments will result in three component seismic data from which travel times will be computed to form a 3D grid of potential sources. A network beamforming approach will be followed to detect, locate, and characterize seismic signals coming from the landslide. This information will provide new insight into the size and nature of the slide of this rock block as well as the degree of internal deformation. This project has a potential broad societal impact and will help quantify and understand the landslide process in general.