標題: Results from parallel observations of superconducting and absolute gravimeters and GPS at the Hsinchu station of Global Geodynamics Project, Taiwan
作者: Hwang, Cheinway
Kao, Ricky
Cheng, Ching-Chung
Huang, Jiu-Fu
Lee, Chiung-Wu
Sato, Tadahiro
土木工程學系
Department of Civil Engineering
公開日期: 21-Jul-2009
摘要: The Hsinchu (HS) superconducting gravimeter (SG, serial T48) station is a newly established site in the Global Geodynamics Project (GGP). Simultaneous observations of T48, three FG5 absolute gravimeters, and GPS at four stations are studied. GPS shows few mm a(-1) of horizontal and vertical motions around HS. The calibration factor and drifting rate of T48 are -75.96 +/- 0.07 mu Gal V(-1) and 0.2 +/- 0.7 mu Gal a(-1) (1 mu Gal = 10(-8) m s(-2)). Both the SG and absolute gravity records contain trends of about 2-3 mu Gal a(-1). The ocean tide gravity effects (OTGEs) were estimated from NAO. 99b, FES2004, and CSR4.0, and their amplitudes agree with the SG observations at the submicroGal level, but their phases differ from the observations up to 10 degrees. The Newtonian effect of ocean tide contributes 20% to the total OTGE at HS, and it is larger at islands in the Taiwan Strait. The inelastic body tide model of Dehant et al. (1999) is more consistent with the SG observations than the elastic model. Modeled gravity-atmosphere admittances based on an exponential distribution of air mass explain well the observed admittances. The average gravity-atmosphere admittance during typhoons is 30% larger than that in a nontyphoon time. A list of coseismic gravity changes from T48 caused by earthquakes over 2006-2007 is given for potential studies of fault parameters. The modeled effects of atmospheric pressure, groundwater, soil moisture, and polar motion explain the FG5 observed gravity trend to 1.1 mu Gal a(-1). Seasonally, the groundwater-induced gravity change contributes the most to the SG residual gravity, but its phase leads the latter by 63 days.
URI: http://dx.doi.org/10.1029/2008JB006195
http://hdl.handle.net/11536/6947
ISSN: 0148-0227
DOI: 10.1029/2008JB006195
期刊: JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
Volume: 114
Issue: 
結束頁: 
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