Nobumasa Takagi's Page                                                   Japanese version is here.


Dear guests for this website.

Thank you for visiting my website.
I graduated from Tohoku University in March 2006,
and I am belonging to a certain company not related to seismology or geophysics.
However, this website remain for the time being.
Nobumasa Takagi


Last modified on March 24, 2006
If you have any questions on this website, please send a E-mail.
takagi @ zisin.geophys.tohoku.ac.jp


Profile

Name Nobumasa Takagi
Academic Year Master course 2nd. in 2005.
Organization Graduate School of Science, Tohoku University
Society Seismological Society of Japan



Study Interest

Estimation of Seismic-Wave Propagation's Process
-Based on the Cross-Correlation Analysis of Coda Waves or Seismic Noise-

  Recently, a new method using multiple scattering waves in heterogeneous media to retrieve Green's function is proposed. As an example of phenomenal study, Campillo and Paul (2003) showed that Rayleigh waves were retrieved from the cross-correlation analysis of coda waves in Mexico. And Snieder (2004) proved that the cross-correlation function calculated from the wave fields recorded at two different points well coincides with Green's function between the two points. Following their studies, I am practicing the cross-correlation analysis of coda waves and/or ambient seismic noise. Obtaining the Green's function, and estimating the seismic-wave propagation's process, I would like to consider the relationship between the propagation's process and the interior structure of the Earth.




Master Thesis

Propagation characteristics of surface waves revealed from the cross-correlation analysis of ambient seismic noise

Abstract (PDF)  in Japanese




Presentation on Academic Society or Workshop

----
Nobumasa Takagi, Haruo Sato , Takeshi Nishimura and Kazushige Obara
Group velocity measurement of Rayleigh and Love waves in northeastern Japan on the basis of the cross-correlation analysis of microseisms
AGU Fall Meeting 2005, Dec., 2005, San Francisco.

Abstract (PDF)    Poster (PDF)   in English

----
Nobumasa Takagi, Haruo Sato and Takeshi Nishimura and Kazushige Obara
Group velocity of Rayleigh waves revealed from the cross-correlation analysis of ambient seismic noise
Workshop for "Scattering Party", Jan., 2006, Earthquake Research Institute, University of Tokyo.

Abstract (PDF)   in Japanese

----
Nobumasa Takagi, Haruo Sato , Takeshi Nishimura and Kazushige Obara
Group velocity of Rayleigh waves revealed from the cross-correlation analysis of ambient seismic noise
Seismological Society Japan 2005 Fall Meetings, Oct., 2005, Sapporo.

Abstract (PDF)   in Japanese

----
Nobumasa Takagi, Haruo Sato and Takeshi Nishimura
Group Velocity of Rayleigh Waves Revealed from the Cross-Correlation Analysis of Ambient Seismic Noise
21COE International Symposium 2005 "Spatial and Temporal Fluctuations in the Solid Earth - Clues to the Future of Our Planet -", Jul., 2005, Sendai.

Abstract (PDF)    Poster (PDF)    in English

----
Nobumasa Takagi, Haruo Sato and Takeshi Nishimura
Propagation Characteristics Revealed from the Cross-Correlation Analysis of Ambient Seismic Noise at a Long Distance
Japan Earth and Planetary Science Joint Meeting, May., 2005, Chiba.

Abstract (PDF)    in English

----
Nobumasa Takagi, Haruo Sato and Takeshi Nishimura,
Detection of Flow of Scattered Waves' Energy
Based on the Cross-Correlation Analysis of Coda Waves
Workshop for "Scattering Party", Jan., 2005, Earthquake Research Institute, University of Tokyo.

Abstract (PDF)   in Japanese

----
Nobumasa Takagi, Haruo Sato and Takeshi Nishimura,
Flow of Scattered Waves' Energy From the Fore-Arc to the Back-Arc in Eastern Japan
Revealed From the Cross-Correlation Analysis of Coda Waves
Workshop on "Probing Earth Media Having Small-Scale Heterogeneities",
Nov., 2004, Sendai.

Abstract (PDF)    Poster (PDF)    in English

----
Nobumasa Takagi, Haruo Sato and Takeshi Nishimura,
Estimation of Seismic-Wave Propagation Velocity
Based on the Cross-Correlation Analysis of Coda Waves,
Seismological Society Japan 2004 Fall Meetings, Oct., 2004, Fukuoka.

Abstract (PDF)    Poster (PDF)   in Japanese