浅部2次元S波速度構造推定を目的とした短周期微動の地震波干渉法解析-岩手大学構内における試み-  [in Japanese] Seismic interferometry analysis of short-period microtremor observed with a linear array for estimating two-dimensional shallow S-wave velocity structures -An experiment in a ground of Iwate University-  [in Japanese]

Access this Article

Search this Article

Author(s)

Abstract

<p>短周期微動を利用しての浅部2次元S波速度構造探査の新たな手法開発を目的とし,岩手大学理工学部グラウンドにおいて11点三成分リニアアレイ微動観測を実施し,上下(UD),radial(NS),transverse(EW)方向の相互相関関数を重合する地震波干渉法による解析を行った。リニアアレイで微動計を等間隔に配置した結果,重合相互相関関数は,NS,EW,UD全ての方向で波動の伝播を確認することができた。マルチプルフィルタ解析により推定した群速度は,特にNS方向でSN比が低く,妥当な推定が困難であった。それに対して,EW,UD方向では,SN比が10より高い周波数範囲が広いことが示された。また,既存モデルから計算したものと比較しても近い値をとっていたことから,妥当な群速度の推定ができたと考えられる。全組み合わせで得られた群速度を2次元表示した結果,高周波数では場所によって群速度が若干変化していることが明らかになった。</p>

<p>We applied seismic interferometry analysis to linear array records of microtremors observed with eleven three-component seismometers in order to aim to develop a new method for exploring shallow two dimensional S wave velocity structures using short period microtremors. As a result, in the stacked cross correlation analysis, it was possible to confirm characteristic phases propagating in all directions of NS, EW and UD as a result of arranging seismometers at equal intervals in the linear array. In estimating the group velocities, the signal to noise ratios (SNRs) were particularly low in the NS direction, and it was difficult to estimate correct group velocities. On the other hand, in the EW and UD directions, it was shown that the frequency range where the SNR is higher than 10 is wide. Moreover, since it was close to the value calculated from the existing model, it is considered that a reasonable group velocity could be estimated. As a result of displaying the group velocity obtained in all combinations in two dimensions, it became clear that the group velocity slightly changed in the horizontal direction at high frequencies.</p>

Journal

  • BUTSURI-TANSA(Geophysical Exploration)

    BUTSURI-TANSA(Geophysical Exploration) 72(0), 17-24, 2019

    The Society of Exploration Geophysicists of Japan

Codes

  • NII Article ID (NAID)
    130007610741
  • NII NACSIS-CAT ID (NCID)
    AN10028069
  • Text Lang
    JPN
  • ISSN
    0912-7984
  • NDL Article ID
    030260899
  • NDL Call No.
    Z15-66
  • Data Source
    NDL  J-STAGE 
Page Top