Since the installation of a dense cabled observation network around the Japan Trench (S-net) by the Japanese government that includes 150 sensors, several tsunami forecasting methods that use the data collected from the ocean floor sensors were developed. One of such methods is the tsunami forecasting method which assimilates the data without any information of earthquakes. The tsunami forecasting method based on the assimilation of the ocean-bottom pressure data near the source area was developed by Tanioka in 2018. However, the method is too simple to be used for an actual station distribution of S-net. To overcome its limitation, we developed an interpolation method to generate the appropriate data at the equally spaced positions for the assimilation from the data observed at sensors in S-net. The method was numerically tested for two large underthrust fault models, a giant earthquake (Mw8.8) and the Nemuro-oki earthquake (Mw8.0) models. Those fault models off Hokkaido in Japan are expected to be ruptured in the future. The weighted interpolation method, in which weights of data are inversely proportional to the square of the distance, showed good results for the tsunami forecast method with the data assimilation. Furthermore, results indicated that the method is applicable to the actual observed data at the S-net stations. The only limitation of the weighted interpolation method is that the computed tsunami wavelengths tend to be longer than the actual tsunamis wavelength.

中文翻译：

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利用海底压力传感器网络（S-net）改进近场海啸预报方法

由于日本政府在日本海沟 (S-net) 周围安装了一个包含 150 个传感器的密集有线观测网络，因此开发了几种使用从海底传感器收集的数据的海啸预报方法。其中一种方法是海啸预报方法，它在没有任何地震信息的情况下同化数据。基于源区附近海底压力数据同化的海啸预报方法是谷冈于2018年开发的，但该方法过于简单，无法用于S-net的实际站点分布。为了克服它的局限性，我们开发了一种插值方法，以在等距位置生成适当的数据，以便从 S-net 中传感器观察到的数据中进行同化。该方法对两个大型逆冲断层模型、大地震（Mw8.8）和根室大地震（Mw8.0）模型进行了数值测试。日本北海道附近的断层模型预计将来会破裂。数据权重与距离的平方成反比的加权插值法对于数据同化的海啸预报方法取得了较好的效果。此外，结果表明该方法适用于S-net站的实际观测数据。加权插值法的唯一限制是计算出的海啸波长往往比实际海啸波长长。日本北海道附近的断层模型预计将来会破裂。数据权重与距离的平方成反比的加权插值法对于数据同化的海啸预报方法取得了较好的效果。此外，结果表明该方法适用于S-net站的实际观测数据。加权插值法的唯一限制是计算出的海啸波长往往比实际海啸波长长。日本北海道附近的断层模型预计将来会破裂。数据权重与距离的平方成反比的加权插值法对于数据同化的海啸预报方法取得了较好的效果。此外，结果表明该方法适用于S-net站的实际观测数据。加权插值法的唯一限制是计算出的海啸波长往往比实际海啸波长长。结果表明，该方法适用于S-net台站的实际观测数据。加权插值法的唯一限制是计算出的海啸波长往往比实际海啸波长长。结果表明，该方法适用于S-net台站的实际观测数据。加权插值法的唯一限制是计算出的海啸波长往往比实际海啸波长长。