Abstract
The Mw
> 9 Sumatra-Andaman earthquake on
December 26, 2004 has strongly excited the lowfrequency
seismic modes and is a unique opportunity to
improve the frequency and damping measurements of the
gravest seismic modes. The precise estimation of the
frequency splitting of the seismic modes below 1 mHz is
needed to improve 1D-density models of the Earth. From
this event, 2S1 is observed for the first time without any
stacking on both SG (Superconducting Gravimeter) and
seismic records. We report here analyses of SG data
obtained from 11 sites. The spectra of SG records clearly
show the splitting of 0S2 into 5 completely resolved singlets
and the splitting of 0S3 into 7 singlets at individual stations.
The present results demonstrate that SGs provide high
quality data for a precise analysis of the low-frequency
seismic modes. Citation: Rosat, S., T. Sato, Y. Imanishi,
J. Hinderer, Y. Tamura, H. McQueen, and M. Ohashi (2005),
High-resolution analysis of the gravest seismic normal modes
after the 2004 Mw = 9 Sumatra earthquake using superconducting
gravimeter data, Geophys. Res. Lett., 32, L13304, doi:10.1029/
2005GL023128.
1.
> 9 Sumatra-Andaman earthquake on
December 26, 2004 has strongly excited the lowfrequency
seismic modes and is a unique opportunity to
improve the frequency and damping measurements of the
gravest seismic modes. The precise estimation of the
frequency splitting of the seismic modes below 1 mHz is
needed to improve 1D-density models of the Earth. From
this event, 2S1 is observed for the first time without any
stacking on both SG (Superconducting Gravimeter) and
seismic records. We report here analyses of SG data
obtained from 11 sites. The spectra of SG records clearly
show the splitting of 0S2 into 5 completely resolved singlets
and the splitting of 0S3 into 7 singlets at individual stations.
The present results demonstrate that SGs provide high
quality data for a precise analysis of the low-frequency
seismic modes. Citation: Rosat, S., T. Sato, Y. Imanishi,
J. Hinderer, Y. Tamura, H. McQueen, and M. Ohashi (2005),
High-resolution analysis of the gravest seismic normal modes
after the 2004 Mw = 9 Sumatra earthquake using superconducting
gravimeter data, Geophys. Res. Lett., 32, L13304, doi:10.1029/
2005GL023128.
1.
| Original language | English |
|---|---|
| Article number | L22601 |
| Pages (from-to) | 1-4 |
| Number of pages | 4 |
| Journal | Geophysical Research Letters |
| Volume | 39 |
| Issue number | 22 |
| DOIs |
|
| Publication status | Published - 6 Aug 2005 |