RAPID: Reconnaissance of Twin Landslides and Tsunami of 17 June 2017 in Greenland

2017年6月17日，滑坡引发的海啸影响了格陵兰西部北方的一个大型峡湾系统。 这个快速反应研究（RAPID）赠款奖支持美国参与对这两起山体滑坡和海啸的侦察调查。 该小组将与格陵兰政府协调勘测活动，并遵循极端地质事件勘测和国际海啸勘测小组（教科文组织）的议定书。 这一事件代表了一个独特的研究机会，因为两个相邻的滑坡活动与不同的结果。 两次滑坡的东部向Karrat峡湾深处1公里，并在Uummannaq峡湾系统引发海啸。 山体滑坡引发的海啸将4名遇难者和几栋房屋冲入距离山体滑坡约30公里的Nuugaatsiaq峡湾。 Nuugaatsiaq和Illorsuit的目击者用视频记录了海啸造成的洪水。 活跃的西部滑坡具有后崖和大裂缝，因此仍然是Karrat Fjord的危险，并导致一些当地村庄的长时间疏散。 该奖项支持的侦察调查团队将收集Karrat Fjord滑坡，悬崖和碎片雪崩轨迹的高质量倾斜航空摄影测量（OAP）以及地面海啸淹没测量。 实地观察将使研究界能够推断不同滑坡和海啸模型的预测能力。 海啸目击者视频将在现场进行校准，以提取水流深度和速度的时间序列。 所得的现场数据将与过去实验项目收集的现有实验室滑坡海啸数据进行密切分析。 主要的项目交付成果将是一个综合的多尺度、地质参考数据库，包括滑坡参数、海啸破坏和洪水区特征，并结合数值模型结果。 将在所调查的土著村庄和访谈的目击者中举办教育和外联讲座和情况介绍会。 格陵兰岛滑坡引发的海啸突出了沿海地区对不常遭受地震引发的海啸的社区的危害。在重大自然和人为事件发生后进行的灾后勘察，对事件的特征以及遭受这些灾难性事件的自然和人为基础设施的性能都有了重要的新见解。 进行这些协调良好、执行良好的滑坡源和海啸勘测活动的好处包括及早收集易腐数据和建立多因素信息数据库，这些数据库构成详细的长期后续调查和主要基于建模的调查的基础。 通过这项研究，研究人员可能能够了解夏至几天内北极地区4人死亡的异常情况。 这一事件代表了一个独特的机会，因为一个滑坡陷入卡拉特峡湾，而另一个相邻的仍然是一个活跃的危险。 这将导致对一次滑坡引发的海啸进行灾后观测，并可能在第二次滑坡引发的海啸发生前获得基线数据。 这两个滑坡体积将估计与倾斜航空摄影测量（OAP）。 与物理模型中的颗粒状滑坡相比，“Sturzbahn”的碎片雪崩体积的传播将提供滑坡基准。 根据最近的山崩和冰川事件，将重新审查海啸的来源和历史上海啸的规模。 收集高质量的洪水测量数据将使社区能够推断不同模型的预测能力，并评估其在洪水绘图和业务预测方面的潜在用途。 本研究生成的数据集和分析工具将在NSF支持的NHERI DesignSafe-CI.org门户网站上提供。 这项研究将为地方当局提供重要信息，因为他们正在考虑滑坡监测和海啸预警系统或永久搬迁疏散的村庄。 它还将为参与侦察的美国学生提供重要的国际经验。

A 17 June 2017 landslide-generated tsunami impacted a large fjord system in the northern part of western Greenland. This Grants for Rapid Response Research (RAPID) award supports the US participation in the reconnaissance survey of the twin landslides and tsunami. The team will coordinate the reconnaissance activities with the Government of Greenland, and follow protocols of the Geotechnical Extreme Events Reconnaissance (GEER) and the International Tsunami Survey Team (UNESCO). This event represents a unique research opportunity since two adjacent landslides were active with different outcomes. The eastern of the two landslides plunged 1 km into the Karrat Fjord and generated a tsunami in the Uummannaq fjord system. The landslide-generated tsunami washed 4 victims and several houses into the fjord at Nuugaatsiaq, about 30 km from the landslide. Eyewitnesses at Nuugaatsiaq and Illorsuit recorded the tsunami inundation on video. The active western landslide features a back scarp and large cracks, and therefore remains a hazard in Karrat Fjord, and has led to extended evacuations of a few native villages. The reconnaissance survey team supported on this award will collect high quality oblique aerial photogrammetry (OAP) of the landslide, scarp, and debris avalanche track as well as ground based tsunami inundation measurements in Karrat Fjord. The field observations will allow the research community to infer the predictive capability of different landslide and tsunami models. Tsunami eyewitness videos will be calibrated in situ to extract time series of flow depth and velocity. The obtained field data will be analyzed closely with the existing laboratory landslide tsunami data collected by past experimental projects. The primary project deliverable will be a comprehensive multi-scale, geo-referenced database of landslide parameters, tsunami damage, and flood zone characteristics combined with numerical model results. Education and outreach lectures and briefings will be given at native villages surveyed and to eyewitnesses interviewed. The Greenland landslide-generated tsunami highlights coastal hazards to communities not commonly exposed to earthquake generated tsunamis.Post disaster reconnaissance following major natural and man-induced events has yielded significant new insights into both the characteristics of the events and the performance of natural and man-made infrastructure subjected to these catastrophic events. The benefits of conducting these well-coordinated, well-executed landslide source and tsunami reconnaissance activities include early collection of perishable data and the establishment of multi-factor databases of information that form the basis for detailed long-term follow-on and mostly modeling based investigations. Through this study, researchers may be able to understand the unusual death toll of 4 people in the Arctic within days of the summer solstice. This event represents a unique opportunity as one landslide plunged into Karrat Fjord, while another neighboring one remains an active hazard. This will lead to post disaster observations of one landslide generated tsunami and potentially before disaster baseline data of a second one. Both landslide volumes will be estimated with oblique aerial photogrammetry (OAP). The spreading of the debris avalanche volume down the "Sturzbahn" will provide a landslide benchmark in comparison with the granular landslide spreading in physical models. The tsunami sources and magnitudes of historic tsunamis will be revisited in light of recent landslide and glaciological events. Collecting high quality inundation measurements will allow the community to infer the predictive capability of different models and evaluate their potential uses for inundation mapping and operational forecasts. Datasets and analytical tools generated by this research will be made available on the NSF-supported NHERI DesignSafe-CI.org web portal. This study will provide important information to local authorities as they are considering landslide monitoring and tsunami warning systems or permanent relocation of the evacuated villages. It will also provide a significant international experience for the U.S. students involved in the reconnaissance.