Validation and Joint Inversion of Teleseismic Waveforms for Earthquake Source Models Using Deep Ocean Bottom Pressure Records: A Case Study of the 2006 Kuril Megathrust Earthquake

Abstract

Abstract-The importance of accurate tsunami simulation has increased since the 2004 Sumatra-Andaman earthquake and the Indian Ocean tsunami that followed it, because it is an important tool for inundation mapping and, potentially, tsunami warning. An important source of uncertainty in tsunami simulations is the source model, which is often estimated from some combination of seismic, geodetic or geological data. A magnitude 8.3 earthquake that occurred in the Kuril subduction zone on 15 November, 2006 resulted in the first teletsunami to be widely recorded by bottom pressure recorders deployed in the northern Pacific Ocean. Because these recordings were unaffected by shallow complicated bathymetry near the coast, this provides a unique opportunity to investigate whether seismic rupture models can be inferred from teleseismic waves with sufficient accuracy to be used to forecast teletsunami. In this study, we estimated the rupture model of the 2006 Kuril earthquake by inverting the teleseimic waves and used that to model the tsunami source. The tsunami propagation was then calculated by solving the linear long-wave equations. We found that the simulated 2006 Kuril tsunami compared very well to the ocean bottom recordings when simultaneously using P and long-period surface waves in the earthquake source process inversion.

Two subevents across the Japan Trench during the 7 December 2012 off Tohoku earthquake (Mw 7.3) inferred from offshore tsunami records

“…Offshore tsunami observations by OBP gauges such as the DART and the seafloor-cabled systems have been very useful with their high signal-to-noise ratios. Several studies have shown benefits of using the deep-sea tsunami records with seismograph data to investigate seismic/ tsunami sources [e.g., Ritsema et al, 1995;Baba et al, 2009;Yamazaki et al, 2011;Yokota et al, 2011]. For typical interplate, megathrust earthquakes that involve relatively simple mechanisms, the slip distributions can be well constrained by tsunami data alone [e.g., Fujii and Satake, 2006;Tang et al, 2009;Gusman et al, 2013].…”

The Effect of the Great Barrier Reef on the Propagation of the 2007 Solomon Islands Tsunami Recorded in Northeastern Australia

“…Similarly, if the actual slip was underneath dry land, instead of the open ocean, that could also cause a substantial change in the tsunami amplitude, even on the coast of Queensland. However, we believe that the teleseismic rupture model we obtained here should have been enough to simulate the tsunami, based on the results from a previous study of the 2006 Kuril Islands earthquake (BABA et al, 2008).…”

The 2006–2007 Kuril Islands great earthquake sequence

“…Moderate‐amplitude tsunamis were produced around the Pacific by the two earthquakes [ Rabinovich et al , 2008; Tanioka et al , 2008; Fujii and Satake , 2008; Baba et al , 2009]. Observed tsunami heights at remote distances were less than 1.2 m for the 15 November 2006 event [ Rabinovich et al , 2008], except for a 1.76 m wave that destroyed two docks and damaged another in Crescent City, California [ Kowalik et al , 2008; Horrillo et al , 2008].…”