巻号一覧
46 巻 (2000)
- 4 号 p. 239-
- 3 号 p. 177-
- 2 号 p. 89-
- 1 号 p. 1-
46 巻, 2 号
選択された号の論文の4件中1～4を表示しています
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松本 剛2000 年 46 巻 2 号 p. 89-108
発行日: 2000/06/25
公開日: 2011/07/05
ジャーナル フリーGravity measurement on the sea bottom is essential to detect the precise structure under neath the sea bottom and to estimate the density of sediment and bedrock. Measurement byuse of on-land survey systems on board the deep sea submersibles SHINKAI 2000 and SHINKAI 6500 was carried out in the tectonically active sites: in the southernmost part of the Toyama Trough and the adjacent Toyama Deep Sea Channel, over the two small knolls located in the southermost part of the "Fukaura Small Hills" off Oga Peninsula, in the WMARK area, western Mid Atlantic Ridge-Kane Transform intersection, etc. In these areas high-precision gravity anomalies higher than those expected from the surface-ship survey were obtained . Active tectonicsoccurring in these sites were discussed through the analysis of the obtained gravity data.抄録全体を表示PDF形式でダウンロード (5259K) -
米澤 千夏, 竹内 章司2000 年 46 巻 2 号 p. 109-124
発行日: 2000/06/25
公開日: 2010/09/07
ジャーナル フリーThe current space-borne C-band ERS-1/SAR and RADARSAT-I data were processed and analyzed experimentally for extracting interferometric fringe. Then the possibility for detecting crustal deformation in several Japanese test sites is discussed . As the result of interfero metric analysis of ERS-1/SAR data, baseline distance should be short for generating initialinterferogram. It is found that the fringe continuity and coherence are significantly affected by not only observation interval but also land cover conditions . That proves that C-band SAR interferometry are more sensitive to ground surface stability than L-band SAR . According to this sensitivity, damaged urban areas by Hyogoken-nanbu earthquake could be detected . Local phase difference change patterns are found from the multi data pairs which interval included the earthquake. The data pair observed in the eastern part of Saitama prefecture with 933 days interval also indicates local fringe patterns which correspond with precise leveling results. As the result of interferometric analysis for RADARSAT-I data, the conditions forextracting continuous fringe are estimated to be similar to that of ERS-1/SAR data . Although the selection of test sites and data pair are important to generate continuous fringe, C-band SAR interferometry is expected to estimate local deformation in urban area.抄録全体を表示PDF形式でダウンロード (11923K) -
矢田部 学2000 年 46 巻 2 号 p. 125-148
発行日: 2000/06/25
公開日: 2010/09/07
ジャーナル フリー天体の形状は自己重力,遠心力,潮汐力など,さまざまな力に支配される.静水圧平衡を仮定すると自己重力のみが作用するとき天体は球対称な形状となる.自己重力以外の力は天体の形状を球対称から外させる.本研究では重力場から自己重力を取り除いた加速度場を残留重力場とよび,それを定式化する.更に,天体の物理形状表面を等ポテンシャル面と見なし残留重力による等ポテンシャル面の変形を静水圧平衡に基づいて論じる.定式化の一つの適用例として水星の形状がコアの扁平率と帯球調和係数J2の関係により考察されている.それによると,水星は,ほとんど球形をしていることが予測される.抄録全体を表示PDF形式でダウンロード (1781K) -
岩野 祥子, 福田 洋一2000 年 46 巻 2 号 p. 149-152
発行日: 2000/06/25
公開日: 2010/09/07
ジャーナル フリーIn order to get precise Bouguer anomalies, terrain correction is very important. Especially for so called micro gravity surveys, which have been widely applied for various purposes recently, the accuracy of the terrain correction seriously de pends on the grid size of Digital Elevation Model (DEM). We thus studied the relation between the accuracy of the terrain correction and the DEM employed for the calculation with a special attention of its spatial resolution. Practically, the 50 mintervals DEM (50 mDEM) published by the Geo graphical Survey Institute have been widely used for gravity terrain correction in Japan . We there fore decided to estimate the accuracy of terrain correction using 50 mDEM as one of the standard cases. We made 10 mDEM from 1/2, 500 city planning maps and compared the two Bouguer gravity anomalies obtained by using the 50 mDEM and the10 mDEM, respectively. The result shows that about 0.2 mgal or a better terrain correction can be obtained only by using the 50 mDEM in topographically flat areas. However, we need more detailed terrain data in topographically steep mountain areas, or even in flat areas to achieve accurate terrain correction of better than 0.1 mgal.抄録全体を表示PDF形式でダウンロード (540K)
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