摘要：The radial seismic normal mode 0 S 0 was strongly excited by the 2004 Mw = 9.3 Sumatra-Andaman earthquake at a period of 20.5 min. In a spherically symmetric Earth model, 0 S 0 amplitude is the same everywhere on the Earth’s surface. However, when the ellipticity and rotation of the Earth are taken into consideration, theoretical computations predict an amplitude of 0 S 0 1% higher at the pole than at the equator. Based on a realistic three-dimensional heterogeneous rotating elliptic Earth model, our predictions indicate that the amplitude of 0 S 0 is 2% higher at the pole than at the equator. A longitude dependency of 0 S 0 amplitude is also shown. The analysis of 13 superconducting gravimeter (SG) records of the 2004 Sumatra-Andaman earthquake supports the predicted geographical variations of 0 S 0 amplitude. We have also obtained new estimates for the frequency and Q of 0 S 0 : 0.8146566±1.6 10 −6 mHz and 5506±19.
