000004695 001__ 4695
000004695 005__ 20141119144545.0
000004695 04107 $$aeng
000004695 046__ $$k2002-06-02
000004695 100__ $$aHigashihara, Hiromichi
000004695 24500 $$aHIGH-RESOLUTION SEISMIC TOMOGRAPHY BASED ON COHERENT WAVE TECHNOLOGIES

000004695 24630 $$n15.$$pProceedings of the 15th ASCE Engineering Mechanics Division Conference
000004695 260__ $$bColumbia University in the City of New York
000004695 506__ $$arestricted
000004695 520__ $$2eng$$aA brand-new high-resolution seismic tomography method is presented. In spite of its great achievements, conventional seismic tomography, which is based on travel time data, has been suffering from low resolution. As an alternative, we have been trying an active seismic tomography based on accurate harmonic wave. Our source is an oscillator that is an eccentric mass driven by a servomotor. Repeating the seismic measurement for a range of different frequencies, we get frequency transfer function. Its Fourier transform yields impulse transfer function that is the key material for the conventional seismological wave analysis. Extremely high precision of frequency of sources enables coherent wave techniques like intensive stacking or phased array of sources. This requires development of a new theory of data analysis based on the indirect measurement strategy. We deployed the instruments in a deep enormous tunnel network of around 600m deep and 5000m wide. This was located in a high seismicity region where moderate size earthquakes of around magnitude six often occur. Detection of change of crustal properties is expected to be a good exercise of the system.

000004695 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000004695 653__ $$aaccurate rotary seismic source (ACROSS), coherent wave technique, scattering tomography, seismic tomography

000004695 7112_ $$a15th ASCE Engineering Mechanics Division Conference$$cNew York (US)$$d2002-06-02 / 2002-06-05$$gEM2002
000004695 720__ $$aHigashihara, Hiromichi$$iSaeki, Masayuki$$iWeiJian, Zeng
000004695 8560_ $$ffischerc@itam.cas.cz
000004695 8564_ $$s82144$$uhttps://invenio.itam.cas.cz/record/4695/files/191.pdf$$yOriginal version of the author's contribution as presented on CD, .
000004695 962__ $$r4594
000004695 980__ $$aPAPER