RAPID: Tsunami deposits and coastal uplift near Concepcion, Chile before and after the major earthquake of February 27, 2010

2010年2月27日，一场灾难性的9级地震和随之而来的海啸袭击了智利中部海岸。这一事件对智利第二大城市康塞普西翁周围地区的影响尤其具有破坏性。该项目将精确记录康塞普西翁地区先前描述的几个研究地点的这次地震和海啸的地貌和构造特征。2009年和2010年初，作者和智利合作者描述并调查了36.5°S至38.5°S之间10个地点的海啸沉积物和上升的沿海海洋平台。Lat. 该项目有两个目标：1）在现有研究地点调查2010年海啸的沉积物和影响，这些研究地点含有康塞普西翁地区以前海啸的地质和历史证据; 2）评估在以前地震中经历过重大隆起的现有研究地点的地震同时和地震后土地水平变化。将在2010年5月至2011年1月期间的两次单独的实地考察中开展实地工作。实地调查将包括在以前记录的地点测绘和测量2010年海啸的侵蚀和沉积影响，以将2010年海啸的沉积物与以前事件的沉积物进行比较;用观测数据校准沉积物;评估海啸沉积物在这一环境中的保存潜力;并利用2010年的沉积物来指导寻找其他可能保存多个古海啸沉积物地层记录的储存库。在陆地水平变化的位置，现场目标将是重新测量在以前的地震中被抬升的海洋平台的高度，我们的团队在2010年1月进行了调查;确定2010年地震中额外抬升的量;为地震后陆地水平变化的后续监测建立基线高程;并将2010年地震中的隆起位置和隆起量与1835年地震后测量的隆起量进行比较。这项研究有可能促进对2010年智利地震规模的灾难性事件的影响，复发和地质特征的了解，这可能导致更好的准备，教育和减少类似沿海地区的生命损失。该项目将使美国-智利合作，促进相互交流知识和专长。对最近海啸和地震引起的海岸隆起的影响进行准确测量，加上先前的测量，将能够完整地记录这些事件的重复发生间隔和受影响最严重的地区。这些数据将对受最近事件破坏的社区的重建进程具有重要价值，调查将在最需要和最有用的地方持续存在。

On February 27, 2010 a catastrophic magnitude 9 earthquake and accompanying tsunami struck the coast of central Chile. The effects of this event were particularly devastating in the area surrounding Concepción, the second largest city in Chile. This project will precisely document the geomorphic and tectonic signatures of this earthquake and tsunami at several previously described study sites in the Concepción region. In 2009 and early 2010 the author and Chilean collaborators described and surveyed tsunami deposits and uplifted coastal marine platforms at 10 sites between 36.5°S to 38.5°S. Lat. The objectives of this project are twofold: 1) Investigate deposits and impacts of the 2010 tsunami at existing study sites containing geological and historical evidence of previous tsunamis in the Concepción area; and 2) Assess co-seismic and post-seismic land-level changes at existing study sites that underwent significant uplift in previous earthquakes. Field work will be conducted in two separate field excursions between May, 2010 and January, 2011. Field investigations will include mapping and surveying the erosional and depositional effects of the 2010 tsunami at the previously documented sites to compare the deposits from the 2010 tsunami with those from previous events; calibrate the sedimentary deposits with the observational data; assess the preservation potential of tsunami deposits in this environment; and use the 2010 deposits to guide the search for additional repositories where stratigraphic records of multiple paleotsunami deposits are likely to be preserved. At the locations of land-level changes the field objectives will be to resurvey heights of marine platforms that were uplifted during previous earthquakes and surveyed by our team in January, 2010; determine the amount of additional uplift in the 2010 earthquake; establish a baseline elevation for subsequent monitoring of post-seismic land-level changes; and compare locations and amount of uplift in the 2010 earthquake with that measured after the 1835 earthquake. This research has the potential to advance knowledge of the impacts, recurrence, and geological signatures of catastrophic events on the scale of the 2010 Chilean earthquake, which could lead to better preparation, education and decreased loss of life in similar coastal areas. The project will occasion U.S.-Chile collaboration that fosters mutual exchanges of knowledge and expertise. An accurate measurement of the effects of the recent tsunami and coastal uplift from the earthquake, together with the prior measurements, will enable a complete documentation of recurrence intervals of these events and the areas that are most affected. These data will be of great value in the rebuilding process for the communities devastated by the most recent event, and the investigation will have a sustainable presence where it will be most needed and useful.