EAPSI: A Better Understanding of Shallow, Subduction Zone Earthquakes Through Bayesian Analysis: A Case Study of the 2015 Illapel, Chile Earthquake

2015年9月16日，里氏8.3级地震导致秘鲁-智利海沟部分破裂。这次事件似乎有一个时间上复杂的破裂，近场和远震距离的仪器都很好地记录了这一事件。拟议的项目将采用一种自适应非线性贝叶斯反演方法，利用从陆地测量和海洋验潮仪和海啸记录收集的数据，解决最近智利地震的断层破裂问题。这种方法通过对数据的显式处理和沿震源区的模型可解析性来量化地震破裂。与其他常规方法相比，这种反演方法的优点是它对测量中的不确定性及其空间和时间分辨率给予了更高的关注。这导致了在网格布置或问题正则化中不引入偏差的情况下提高了置信度的反演结果。这项研究将在菲尔·康明斯教授的指导下在澳大利亚国立大学地球科学学院进行。康明斯集团以数学和地球物理角度的地震学和海啸波传播方面的专业知识而闻名。2015年9月16日，智利中部海岸发生大地震，过去几十年来，该地区经常发生极大的破坏性地震。对破裂的空间和时间成分的初步分析表明，这一事件本质上是复杂的。该项目与澳大利亚国立大学的研究科学家合作，提议通过使用非线性贝叶斯自适应反演来量化2015年智利地震的滑动。这种方法更注重所使用的每一种测量的不确定性以及它们的空间和时间分辨率。这可以更好地理解地震是如何破裂的，同时最大限度地减少分析师主导的偏差，这可能会极大地改变模型的结果。最终，该项目的结果有助于更好地了解秘鲁-智利海沟这一地区的地震危险性。该奖项由东亚和太平洋夏季学院项目资助一名美国研究生的暑期研究，由NSF和澳大利亚科学院联合资助。

On September 16, 2015, a Mw 8.3 earthquake ruptured a portion of the Peru-Chile trench. This event appears to have a temporally complex rupture and was well recorded by instruments both in the near-field and at teleseismic distances. The proposed project will apply an adaptive non-linear Bayesian inversion method to solve for the fault rupture of the recent Chilean earthquake, using the preponderance of collected data from both on-land measurements and ocean based tide gauge and tsunami recordings. This approach results in a quantification of the earthquake rupture through an explicit treatment of the data and model resolvability along a source region. The benefit of this type of inversion method compared to other conventional methods is that it gives a higher level of focus to the uncertainties in measurements and their spatial and temporal resolvability. This leads to an inversion result that has improved confidence levels without introducing biases in grid placement or problem regularization. This research will be conducted at the Australian National University School of Earth Sciences under the mentorship of Professor Phil Cummins. The Cummins group is noted for specialized expertise in seismology and tsunami wave propagation from a mathematical and geophysical perspective.On September 16, 2015, a large magnitude earthquake struck of the coast of Central Chile in a region that has been prone to very large and destructive earthquakes over the past decades. An Initial analysis of the spatial and temporal components of the rupture suggests that this event was complex in nature. In conjunction with research scientists at the Australian National University, this project proposes to quantify the slip from the 2015 Chile earthquake through use of a non-linear Bayesian adaptive inversion. This approach gives a higher level of focus on the uncertainties of each measurement used as well as their spatial and temporal resolvability. This results in a better understanding of how the earthquake ruptured while minimizing the amount of analyst led biases, which can greatly alter the model results. Ultimately, the results of this project allows for a better understanding of the seismic hazard of this region of the tectonically active Peru-Chile trench. This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the Australian Academy of Science.