Observation and modeling of thermoelastic strain in Southern California Integrated GPS Network daily position time series

被引:74
作者
Prawirodirdjo, L
Ben-Zion, Y
Bock, Y
机构
[1] Univ Calif San Diego, Scripps Inst Oceanog, Inst Geophys & Planetary Phys, La Jolla, CA 92093 USA
[2] Univ So Calif, Dept Earth Sci, Los Angeles, CA 90089 USA
关键词
D O I
10.1029/2005JB003716
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
We suggest that strain in the elastic part of the Earth's crust induced by surface temperature variations is a significant contributor to the seasonal variations observed in the spatially filtered daily position time series of Southern California Integrated GPS Network (SCIGN) stations. We compute the predicted thermoelastic strain from the observed local atmospheric temperature record assuming an elastically decoupled layer over a uniform elastic half-space and compare the seasonal variations in thermoelastic strain to the horizontal GPS position time series. We consider three regions (Palmdale, 29 Palms, and Idyllwild), each with one temperature station and three to six GPS stations. The temperature time series is used to compute thermoelastic strain at each station on the basis of its relative location in the temperature field. For each region we assume a wavelength for the temperature field that is related to the local topography. The depth of the decoupled layer is inferred from the phase delay between the temperature record and the GPS time series. The relative amplitude of strain variation at each GPS station, calculated to be on the order of 0.1 mu strain, is related to the relative location of that station in the temperature field. The goodness of fit between model and data is evaluated from the relative amplitudes of the seasonal signals, as well as the appropriateness of the chosen temperature field wavelength and decoupled layer depth. The analysis shows a good fit between the predicted strains and the GPS time series. This suggests that the model captures the key first-order ingredients that determine the thermoelastic strain in a given area. The results can be used to improve the signal/noise ratio in GPS data.
引用
收藏
页数:10
相关论文
共 16 条
[1]  
[Anonymous], 2002, EARTH SCI-WUHAN, DOI DOI 10.1029/2001JB000329
[2]   Tectonic contraction across Los Angeles after removal of groundwater pumping effects [J].
Bawden, GW ;
Thatcher, W ;
Stein, RS ;
Hudnut, KW ;
Peltzer, G .
NATURE, 2001, 412 (6849) :812-815
[3]  
BEN-ZION Y, 1986, B SEISMOL SOC AM, V76, P1447
[4]   NOTE ON THERMOELASTIC STRAINS AND TILTS [J].
BERGER, J .
JOURNAL OF GEOPHYSICAL RESEARCH, 1975, 80 (02) :274-277
[5]   Effect of annual signals on geodetic velocity -: art. no. 2145 [J].
Blewitt, G ;
Lavallée, D .
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, 2002, 107 (B7)
[6]   A new global mode of Earth deformation:: Seasonal cycle detected [J].
Blewitt, G ;
Lavallée, D ;
Clarke, P ;
Nurutdinov, K .
SCIENCE, 2001, 294 (5550) :2342-2345
[7]  
CLARK SP, 1966, HDB PHYS CONSTANTS M
[8]   Anatomy of apparent seasonal variations from GPS-derived site position time series [J].
Dong, D ;
Fang, P ;
Bock, Y ;
Cheng, MK ;
Miyazaki, S .
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, 2002, 107 (B4)
[9]   Seasonal modulation of interseismic strain buildup in northeastern Japan driven by snow leads [J].
Heki, K .
SCIENCE, 2001, 293 (5527) :89-92
[10]   Aliased tidal signatures in continuous GPS height time series [J].
Penna, NT ;
Stewart, MP .
GEOPHYSICAL RESEARCH LETTERS, 2003, 30 (23) :SDE1-1