Descriptions This dataset contains supplementary materials for the manuscript under revision for Geophysical Research Letters; the preprint has been uploaded to ESS Open Archive: Sandanbata, O., Watada, S., Satake, K., Kanamori, H., & Rivera, L. (2023). Two volcanic tsunami events caused by trapdoor faulting at a submerged caldera near Curtis and Cheeseman Islands in the Kermadec Arc. Geophysical Research Letters, 50, e2022GL101086. https://doi.org/10.1029/2022GL101086 We constructed a source model for the 2017 earthquake at Curtis caldera in the Kermadec Arc. The dislocation distributions and source geometries of this source model, presented in Figure 3, are contained in this dataset.
Abstract. On 4 March 2021, two tsunamigenic earthquakes (Mwâ7.4 and Mwâ8.1) occurred successively within 2âh in the Kermadec Islands, offshore New Zealand. We examined sea level records at tide gauges located at â¼100 to â¼2000âkm from the epicenters, conducted Fourier and wavelet analyses as well as numerical modeling of both tsunamis. Fourier analyses indicated that the energy of the first tsunami is mainly distributed over the period range of 5â17âmin, whereas it is 8â32âmin for the second tsunami. Wavelet plots showed that the oscillations of the first tsunami continued even after the arrival of the second tsunami. As the epicenters of two earthquakes are close to each other (â¼55âkm), we reconstructed the source spectrum of the second tsunami by using the first tsunami as the empirical Green's function. The main spectral peaks are 25.6, 16.0, and 9.8âmin. The results are similar to those calculated using tsunami-to-background ratio method and are also consistent with the source models.
We conduct moment tensor (MT) inversion for the 2005 earthquake at the Sierra Negra caldera, the Galapagos Islands. For the inversion, we assumed different centroid locations in 3D space, i.e., on the x–y (longitude-latitude) plane at a depth of 2.5 km below the solid surface, and the x–z (longitude–depth) plane along a latitude of 0.83°S across the Sierra Negra caldera. Data Sets S1 and S2 contain MT solutions obtained by the MT inversion with a constraint of zero trace; those solutions are used for Figure 7 in "Main Text". Data Sets S3 and S4 contain MT solutions obtained by the MT inversion with constrains of zero trace and zero DS component (\(M_{r\theta}=M_{r\phi}=0\)); those are are used for Figure S1 in "Supporting Information". For the detailed methodology and data, see Section 3 in "Main Text" and Text S1 in "Supporting Information" of our manuscript.
Abstract Teleseismic body wave analysis revealed that the 7 December 2012 off‐Sanriku earthquake ( M W 7.3) at the outer rise of Japan Trench consisted of two successive subevents. The first subevent with reverse‐fault mechanism (Event 1, M W 7.1) at 56 km depth was followed by, approximately 20 s later, the second subevent with normal‐fault mechanism (Event 2, M W 7.2) at 6 km depth. Finite‐fault slip models show that the slip of Event 1 was concentrated around the initial rupture point with the maximum of 2.7 m and that Event 2 had two asperities with the maximum of 4.5 m at both sides of the initial rupture point. The static Coulomb Failure Function analyses suggested that Event 1 triggered Event 2 and that both subevents were promoted by the 2011 Tohoku earthquake ( M W 9.1).
Kenji Satake (Active Fault Research Center, GSJ/AIST) Than Tin Aung (Research Center for Deep Geological Environments, GSJ/AIST) Yuki Sawai (Active Fault Research Center, GSJ/AIST) Yukinobu Okamura (Active Fault Research Center, GSJ/AIST) Kyaw Soe Win (Nagoya University) Win Swe (Myanmar Geoscience Society) Chit Swe (Yangon Technological University) Tint Lwin Swe (Yangon Technological University) Soe Thura Tun (Yangon University) Maung Maung Soe (Department of Meteorology and Hydrology) Thant Zin Oo (Department of Meteorology and Hydrology) Saw Htwe Zaw (Myanmar Engineering Society)
The December 2004 Indian Ocean tsunami was the worst tsunami disaster in the world's history with more than 200,000 casualties. This disaster was attributed to giant size (magnitude M ~ 9, source length >1000 km) of the earthquake, lacks of expectation of such an earthquake, tsunami warning system, knowledge and preparedness for tsunamis in the Indian Ocean countries. In the last ten years, seismology and tsunami sciences as well as tsunami disaster risk reduction have significantly developed. Progress in seismology includes implementation of earthquake early warning, real-time estimation of earthquake source parameters and tsunami potential, paleoseismological studies on past earthquakes and tsunamis, studies of probable maximum size, recurrence variability, and long-term forecast of large earthquakes in subduction zones. Progress in tsunami science includes accurate modeling of tsunami source such as contribution of horizontal components or "tsunami earthquakes", development of new types of offshore and deep ocean tsunami observation systems such as GPS buoys or bottom pressure gauges, deployments of DART gauges in the Pacific and other oceans, improvements in tsunami propagation modeling, and real-time inversion or data assimilation for the tsunami warning. These developments have been utilized for tsunami disaster reduction in the forms of tsunami early warning systems, tsunami hazard maps, and probabilistic tsunami hazard assessments. Some of the above scientific developments helped to reveal the source characteristics of the 2011 Tohoku earthquake, which caused devastating tsunami damage in Japan and Fukushima Dai-ichi Nuclear Power Station accident. Toward tsunami disaster risk reduction, interdisciplinary and trans-disciplinary approaches are needed for scientists with other stakeholders.
