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Estimation of underground structures in the Osaka-Kobe area by array-network observations of microtremors; Bido no array kansoku ni yoru Osaka-Hyogo chiiki no chika kozo no suitei

Abstract

Microtremor observations have been carried out with an objective to estimate underground structures including the foundation depth in the Osaka-Kobe area which has been greatly damaged by the Hyogoken-nanbu earthquake in 1995. Different organizations have made seismic surveys and boring investigations in this area, by which elucidation has been made on the underground structures. The present observations are intended to identify S-wave velocity distribution in a wide area from the ground surface to the foundation, which is difficult to be verified by using conventional surveys and investigations. Methods to detect surface waves which are contained in microtremors include the frequency-wave number method (the F-K method) and the spatial autocorrelation method (the SPAC method). The SPAC method can estimate phase velocities of longer waves for the size of an array than with the F-K method, and is more advantageous in estimating ground structures at greater depths. S-wave velocity structure was estimated down to the foundation rocks existing in depths of about 0.5 to 2.0 km. For estimating the phase velocities in Raleigh waves, the SPAC method and the expanded spatial autocorrelation method were used. The underground structures thus derived showed a good agreement with the results of explorations using other methods.  More>>
Authors:
Okada, H; Ishikawa, K; Ling, S; [1]  Sasabe, K [2] 
  1. Hokkaido University, Sapporo (Japan)
  2. Ministry of Construction, Tokyo (Japan)
Publication Date:
May 27, 1997
Product Type:
Conference
Report Number:
CONF-9705167-
Reference Number:
SCA: 150301; 580000; PA: NEDO-97:912292; EDB-97:116188; SN: 97001846584
Resource Relation:
Conference: 96. SEGJ conference, Butsuri tansa gakkai dai 96 kai (1997 nendo shunki) gakujutsu koenkai, Tokyo (Japan), 27-29 May 1997; Other Information: PBD: 27 May 1997; Related Information: Is Part Of Proceeding of the 96th (spring, fiscal 1997) SEGJ Conference; PB: 502 p.; Butsuri tansa gakkai dai 96 kai (1997 nendo shunki) gakujutsu koenkai koen ronbunshu
Subject:
15 GEOTHERMAL ENERGY; 58 GEOSCIENCES; SEISMIC ARRAYS; MICROEARTHQUAKES; GEOLOGIC STRUCTURES; JAPAN; SUBSURFACE STRUCTURES; VELOCITY; SEISMIC S WAVES; DISTRIBUTION; BASEMENT ROCK; RAYLEIGH WAVES; PHASE SHIFT
OSTI ID:
522692
Research Organizations:
Society of Exploration Geophysicists of Japan, Tokyo (Japan)
Country of Origin:
Japan
Language:
Japanese
Other Identifying Numbers:
Other: ON: DE97770262; TRN: 97:912292
Availability:
Available from The Society of Exploration Geophysicists of Japan, 2-18, Nakamagome 2-chome, Ota-ku, Tokyo, Japan; OSTI as DE97770262
Submitting Site:
NEDO
Size:
pp. 435-439
Announcement Date:
Sep 29, 1997

Citation Formats

Okada, H, Ishikawa, K, Ling, S, and Sasabe, K. Estimation of underground structures in the Osaka-Kobe area by array-network observations of microtremors; Bido no array kansoku ni yoru Osaka-Hyogo chiiki no chika kozo no suitei. Japan: N. p., 1997. Web.
Okada, H, Ishikawa, K, Ling, S, & Sasabe, K. Estimation of underground structures in the Osaka-Kobe area by array-network observations of microtremors; Bido no array kansoku ni yoru Osaka-Hyogo chiiki no chika kozo no suitei. Japan.
Okada, H, Ishikawa, K, Ling, S, and Sasabe, K. 1997. "Estimation of underground structures in the Osaka-Kobe area by array-network observations of microtremors; Bido no array kansoku ni yoru Osaka-Hyogo chiiki no chika kozo no suitei." Japan.
@misc{etde_522692,
title = {Estimation of underground structures in the Osaka-Kobe area by array-network observations of microtremors; Bido no array kansoku ni yoru Osaka-Hyogo chiiki no chika kozo no suitei}
author = {Okada, H, Ishikawa, K, Ling, S, and Sasabe, K}
abstractNote = {Microtremor observations have been carried out with an objective to estimate underground structures including the foundation depth in the Osaka-Kobe area which has been greatly damaged by the Hyogoken-nanbu earthquake in 1995. Different organizations have made seismic surveys and boring investigations in this area, by which elucidation has been made on the underground structures. The present observations are intended to identify S-wave velocity distribution in a wide area from the ground surface to the foundation, which is difficult to be verified by using conventional surveys and investigations. Methods to detect surface waves which are contained in microtremors include the frequency-wave number method (the F-K method) and the spatial autocorrelation method (the SPAC method). The SPAC method can estimate phase velocities of longer waves for the size of an array than with the F-K method, and is more advantageous in estimating ground structures at greater depths. S-wave velocity structure was estimated down to the foundation rocks existing in depths of about 0.5 to 2.0 km. For estimating the phase velocities in Raleigh waves, the SPAC method and the expanded spatial autocorrelation method were used. The underground structures thus derived showed a good agreement with the results of explorations using other methods. 8 figs., 1 tab.}
place = {Japan}
year = {1997}
month = {May}
}