1/2 times what equals 1/2? What divided by 1/4 equals 3/5? What is 2 over 3 as a percentage? How to calculate 3/4 plus 1/9 Is 1/2 greater than 1/3? What is 4.56 as a fraction? How to calculate 3/7 divided by 4/5 Equivalent Fractions of 3/9 What is the factorial of 6? 1/2 divided by what equals 3/4? Reduce 5/25 What times 1/3 equals 1/2? The Panic File Museum. Welcome to everything we've ever made. Note: old software is unsupported.

Seismic coda attenuation after the Mw = 6.2 Armenia (Colombia) earthquake of 25 January 1999

Coda 2 7 5 Equals

Abstract

Seismic wave attenuation in the central region of the Colombian Andes is studied using coda waves. Most of the events used occurred in the region on the occasion of the Armenia 25 January 1999 earthquake. The estimation of the decay rate of coda amplitudes (called coda Q-1 or Qc-1) is performed by means of the single isotropic scattering method of Sato [1977]. The attenuation parameters Qi-1 (intrinsic absorption), Qs-1 (scattering loss), and Qt-1 (total attenuation) are also estimated using the multiple lapse time window method of Hoshiba et al. [1991]. The frequencies of interest lie between 1 and 15 Hz. Results show that scattering attenuation is predominant for the frequency bands 1.5 +/- 0.5 and 13.5 +/- 1.5 Hz, whereas the intrinsic absorption and scattering contribute in equal shares to total attenuation for the 3 +/- 1, 5 +/- 1, 7.5 +/- 1.5, and 10.5 +/- 1.5 Hz frequencies. A comparison among the estimated attenuation parameters indicates that Qc-1 is close to total attenuation for all the studied frequency bands. On the other hand, no evidence in support of temporal changes of Qc-1 before and after the main shock has been found. Finally, the regionalization of Qc-1 values seems to correlate well with the geotectonic characteristics of the region.


Publication:
Pub Date:
June 2002
DOI:
10.1029/2001JB000197

Coda 2 7 5 Equals 9

Bibcode:
2002JGRB..107.2107U
Keywords:
  • Seismology: Body wave propagation;
  • Seismology: Lithosphere and upper mantle;
  • Information Related to Geographic Region: South America

Seismic coda attenuation after the Mw = 6.2 Armenia (Colombia) earthquake of 25 January 1999

Abstract

Coda 2 7 5 Equals

Seismic wave attenuation in the central region of the Colombian Andes is studied using coda waves. Most of the events used occurred in the region on the occasion of the Armenia 25 January 1999 earthquake. The estimation of the decay rate of coda amplitudes (called coda Q-1 or Qc-1) is performed by means of the single isotropic scattering method of Sato [1977]. The attenuation parameters Qi-1 (intrinsic absorption), Qs-1 (scattering loss), and Qt-1 (total attenuation) are also estimated using the multiple lapse time window method of Hoshiba et al. [1991]. The frequencies of interest lie between 1 and 15 Hz. Results show that scattering attenuation is predominant for the frequency bands 1.5 +/- 0.5 and 13.5 +/- 1.5 Hz, whereas the intrinsic absorption and scattering contribute in equal shares to total attenuation for the 3 +/- 1, 5 +/- 1, 7.5 +/- 1.5, and 10.5 +/- 1.5 Hz frequencies. A comparison among the estimated attenuation parameters indicates that Qc-1 is close to total attenuation for all the studied frequency bands. On the other hand, no evidence in support of temporal changes of Qc-1 before and after the main shock has been found. Finally, the regionalization of Qc-1 values seems to correlate well with the geotectonic characteristics of the region.


Publication:
Pub Date:
June 2002
DOI:
10.1029/2001JB000197
Bibcode:
2002JGRB..107.2107U
Keywords:

Coda 2 7 5 Equals 1

Many
  • Seismology: Body wave propagation;
  • Seismology: Lithosphere and upper mantle;
  • Information Related to Geographic Region: South America