RAPID: Quantifying Temporal Changes in Rockfall Magnitude-Frequencies for Well-Characterized Rockslopes Shaken by the 2018 Alaska Earthquake

RAPID：量化 2018 年阿拉斯加地震震动的特征明确的岩坡落石震级频率的时间变化

• 批准号: 1929304
• 负责人: Ben Leshchinsky
• 金额: $ 5.5万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-15 至 2020-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1929304&HistoricalAwards=false
• 关键词: RAPID; Quantifying; Temporal; Changes; Rockfall

Earthquakes cause many hazards during shaking, but some of the hazards linger long after the seismic event is over. For example, heightened frequency of landslides and rockfalls commonly occur in the months - and even years - following an earthquake. This Rapid Response Research (RAPID) project seeks to capture perishable data from several rock slopes highly susceptible to rockfall that were affected by the recent earthquake in Anchorage. By doing this, we may compare the rate and frequency of rockfall occurrence to pre-earthquake levels in order to better understand how much rockfall activity increases following shaking, and how long it takes to return to pre-earthquake levels. This has implications for post-earthquake recovery and seismic resilience throughout much of the US and abroad. Earthquakes often trigger significant rockfall activity in steep cliffs. The recent 2018 November 30th Alaska earthquake caused significant shaking (up to 0.4g) across the Anchorage region, resulting in numerous rockfalls, landslides, and lateral spreads. The combination of potentially large volumes, high velocities, long travel distances, and impact forces make the rockfall hazard significant. Based on observations from past events in New Zealand, it is believed that rockfall activity over at least the next several months will exceed "normal" baseline levels before decreasing. Nevertheless, as is often the case, the previous research does not have detailed baseline information prior to the event. This prior research begs three primary scientific questions: what is "baseline" rockfall activity? How does shaking translate to increased rockfall activity, magnitude, and frequency particularly in the heterogenous geologic conditions encountered in the rock slopes surrounding Anchorage? And lastly, how quickly does rockfall activity and magnitude return to baseline conditions? This project seeks to collect rockfall activity rates through repeat terrestrial laser scanning at well-characterized rockfall sites near Anchorage. Change detection will be performed and the rate of rockfall activity characterized in comparison to previous epochs and the serial data collected as part of this project. With existing baseline data not influenced by recent seismic activity, we will characterize and compare the activity rate following shaking. This investigation will provide fundamental knowledge about the process that dictates both the increase and decay in rockfall activity after seismic disturbance. The resulting knowledge will provide data needed to support and advance modern performance- and risk-based extreme event design methodologies.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

地震在摇晃过程中造成许多危险，但是在地震事件结束很久之后，其中一些危害持续了下来。例如，地震后几个月甚至几年发生的几个月甚至几年，山体滑坡和岩石的频率升高。这项快速响应研究（快速）项目旨在捕获几个受到摇滚极易受到岩石fall的影响的易腐烂数据，这些岩石受到摇滚的影响，这些岩石受到锚定近期地震的影响。通过这样做，我们可以将岩石发生的速率和频率与练习前水平进行比较，以便更好地了解摇晃后的落叶活动增加了多少，以及返回到射线前的水平需要多长时间。 这对美国和国外大部分地区的地震后恢复和地震韧性具有影响。 地震经常引发陡峭的悬崖上的巨大摇摆活动。最近的2018年11月30日阿拉斯加地震在整个锚地区域造成了巨大的摇动（高达0.4克），导致许多岩石，滑坡和侧向蔓延。潜在的大容量，高速度，长途距离和影响力的结合使岩石危险危险很大。基于新西兰过去事件的观察结果，据信至少在接下来的几个月中的岩石活动在减少之前将超过“正常”基线水平。然而，正常情况下，以前的研究在活动之前没有详细的基线信息。这项先前的研究提出了三个主要的科学问题：什么是“基线”摇滚活动？摇动如何转化为增加的岩石活动，幅度和频率，特别是在锚固周围的岩石斜率中遇到的异质地质条件下？最后，摇滚活动和幅度恢复到基线条件的速度如何？ 该项目旨在通过在安克雷奇附近的良好特征岩石场所进行重复的陆地激光扫描来收集落石活动率。将进行变更检测，并且与以前的时期相比，岩石活动的速率和作为该项目的一部分收集的序列数据的特征。由于现有的基线数据不受最近的地震活动的影响，我们将表征和比较摇晃后的活动率。这项调查将提供有关地震干扰后岩石活动活动的增加和衰减过程的基本知识。最终的知识将提供支持和推进基于现代性能和风险的极端事件设计方法所需的数据。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛的影响审查标准通过评估来支持的。