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Volume 49 (2003)
- Issue 4 Pages 215-
- Issue 3 Pages 159-
- Issue 2 Pages 99-
- Issue 1 Pages 1-
Volume 49, Issue 2
Displaying 1-5 of 5 articles from this issue
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Yoshimitsu Okada2003 Volume 49 Issue 2 Pages 99-119
Published: June 25, 2003
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSParadoxical behaviors are sometimes observed in vertical surface displacement fields due to a fault model. The details of the phenomena were analyzed and their causes were investi gated. (1) The subsidence of the foot-wall side of an infinitely long thrust fault breaking the ground surface turns to upheaval when the dip angle is smaller than 30 deg and the fault length becomes short. This is caused by the leaking out of the large displacement on the hanging-wall side to the foot-wall side through both edges of the fault . (2) The subsidence above a buried vertical tensile fault disappears when the fault length becomes infinite . This is caused by the vanishing of the interference of the subsidence fields generated at both endsof the fault. (3) When a buried thrust fault comes up to the ground surface, a peaking pattern appears around the shallower edge and it vanishes when the fault surface breaks the ground. The peaking is caused by the direction change of the displacement on the hanging-wall side toward the ground surface to where the resistance of the medium is small . When the fault surface cuts the ground, such a direction change suddenly becomes to be unnecessary . At the edges of a finite fault surface with a uniform dislocation, some mathematical singu larities appear in the displacement field. For the displacement component parallel to the dislocation, it exists the multi-valued singularity, whereas logarithmic infinity appears in the displacement component normal to the fault surface for a shear fault and in the displacement component toward the fault surface for a tensile fault . These singularities come from the dis placement fields due to a fault model in an infinite medium. They will disappear if the dislo cation is not uniform over the fault surface and the spatial pattern becomes continuous at the fault edge.View full abstractDownload PDF (2468K) -
Akio Kobayashi, Takeyasu Yamamoto, Hiromi Takayama, Akio Yoshida2003 Volume 49 Issue 2 Pages 121-133
Published: June 25, 2003
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSCrustal deformations in the Chubu-Kanto region at and after the 2000 seismo-volcanic activity around the northern Izu islands were investigated using GEONET coordinate data of the Geographical Survey Institute. We found that three kinds of crustal deformations of different spatial patterns occurred successively. The first and the most prominent deformation was the one produced by the seismo-volcanic activity between Miyake and Kozu islands. The second kind deformation, characterized by southward displacement of the crustal block in the Chubu district, occurred after the peak of the first one. The third one is the on-going eastward displacement that became noticeable in 2001 along the coastal region of Aichi and Shizuoka Prefectures. It is shown that the second kind deformation was diffusive. We think the tem poral change in the displacement field might have been a viscoelastic response of the crust mantle system triggered by the extensive elastic deformation in the Kanto-Tokai region at the time of the northern Izu islands event.View full abstractDownload PDF (6702K) -
Hongwei Sun, Michito Imae, Tadahiro Gotoh2003 Volume 49 Issue 2 Pages 135-142
Published: June 25, 2003
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSThe accuracy of two-way satellite time and frequency transfer (TWSTFT) in the Asia-Pacific region was estimated. The factors affecting the accuracy are satellite motion, the Earth's atmosphere and the ground station equipment. The estimated accuracy was about 1.5 nanoseconds. Comparisons of several time scales in the Asia-Pacific region by means of the TWSTFT and GPS common-view (GPS-CV) methods showed that the time transfer stability of the TWSTFT method is better than that of the GPS-CV method for sampling periods of less than 20 days, while their longer term stabilities are about the same.View full abstractDownload PDF (781K) -
Yuki Hatanaka2003 Volume 49 Issue 2 Pages 143-152
Published: June 25, 2003
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSIt is found that defects of clustering configurations of GPS networks has a significant im pact on the stability of the combined solution by checking results of a test analysis of GPS Earth Observation Network (GEONET). Four kinds of factors are involved in the biases and variations of the solutions; constraint of fiducial-free solutions arose from fixed orbits, system atic error in the fiducial-free solutions, imbalance of data weight, and weakness of connec tivity of the sub-networks and clusters. The existence of modeling errors in GPS analysis is inferred from the second one. This problem was successfully removed by improving the connectivity of the network with a careful choice of network nodes. The variance of height component of the three-week solutions is reduced by 30% by adopting the improved network configuration.View full abstractDownload PDF (1124K) -
Takeshi Iinuma2003 Volume 49 Issue 2 Pages 153-154
Published: June 25, 2003
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSDownload PDF (1160K)
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