Makoto OKUBO

Dr. Makoto OKUBO

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Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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20 March 2025 in Research Square
Verified
Preprint
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NDNguyen Anh Duong
Nguyen Anh Duong
ICIkuo Cho
Ikuo Cho
MOMakoto OKUBO
Makoto OKUBO
TVTuan Minh Vu
Tuan Minh Vu
HNHai Thanh Nguyen
Hai Thanh Nguyen
YLYen Thi Hai Le
Yen Thi Hai Le
We have developed maps of the predominant period of the ground and average S-wave velocity to depths of 10, 20 and 30 m (VS10, 20 and 30) as the fundamental data for seismic hazard assessment for Hue City, Central Vietnam. We conducted microtremor single-station measurements at 461 sites and microtremor array measurements at 157 sites in and around the city (i.e., within an area of about 15 km x 15 km). The peak period of horizontal-to-vertical spectral ratios (HVSR) obtained from three-component microtremor waveforms at a single station were regarded as a S-wave predominant period of the ground. Rayleigh-wave phase velocity at wavelengths of 13, 25 and 40 m obtained from vertical-component array measurements were regarded as VS10, 20 and 30, respectively. It revealed that the predominant periods range from 0.03 to 1.98 s (i.e., 0.5 to 33 Hz) in Hue City, which show a tendency to be longer in the northern part of the city than in the southern part. The analysis results of the average S-wave velocity indicate that soft sediments are very thick in the northern part of the city, where VS10, 20 and 30 ranges from 149 to 189 m/s. These analysis results are consistent with an existing geological map and quantify the geoenvironmental conditions in Hue City, indicating the effectiveness of the microtremor measurements for a seismic assessment.

18 October 2015
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Book Chapter
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MOMakoto OKUBO
Makoto OKUBO
HOHiroshi Ogasawara
Hiroshi Ogasawara
SNShigeru Nakao
Shigeru Nakao
OMOsamu Murakami
Osamu Murakami
HIHiroshi Ishii
Hiroshi Ishii
AWAnthony K. Ward
Anthony K. Ward