Abstract
The Earth's surface is under the continuous influence of a variety of natural forces and human induced sources. Strain data are good examples of such disturbed signals. To determine the geodetic strain behavior before and after the 2003 Tokachi-oki earthquake (M8.0), we decomposed the disturbed strain data into trend, air pressure, earth tide, and precipitation responses components. The decomposition of the disturbed strain data and the interpolation of the missing observations are performed very effectively by using state-space modeling and the Kalman filter/smoother. The validity of the data processing is confirmed by the fact that the model derived to fit the strain data matches the GPS data extremely well.
1The following contribution was presented at the WDS conference and presents a more complete explanation of the data processing and its implementation. Subsequent to the Conference, the authors completed their research and have published a comprehensive paper presenting their final results in [Modeling of the post-seismic slip of the 2003 Tokachi-oki earthquake M8 off Hokkaido: constraints from volumetric strain, Earth, Planets and Space, doi: 10.5047/eps.2012.12.003, in press]. That paper includes not only a preliminary data processing presented here, but also contains many additional results concerned with a geophysical phenomenon. The CODATA Data Science Journal regrets the delay in publishing this conference paper.