Construction of Gravity anomaly map in whole Peru

秘鲁全境重力异常图构建

• 批准号: 07041090
• 负责人: FUKAO Yoshio
• 金额: $ 6.78万
• 依托单位: University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for international Scientific Research
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07041090/
• 关键词: Peruvian Andes; gravity anomaly; Peru; mountain building; terrain correction; Bouguer Anomaly; プ-ゲ-異常; 山脈隆起

We proposed a joint study for the processing of gravity data which were accumulated by the Instituto Geofisico del Peru (IGP) over the last 40 years. The primay objectives of this project is to carry out various researches by both Japanese and Peruvian participants in order (a) to check the correctness of IGP gravity data sets from the most basic level, (b) to repeat gravity measurements to obtain accurate data which can be used as the reference values, (c) to perform field surveys to obtain new gravity profiles over tectonically interesting areas, and (d) to compile all the available data into a Bouguer anomaly map of Peru and publish the map from IGP.We obtained the original readings of the gravity surveys of IGP from the field notes and digitized them completely. Using the constant tables for individual gravimeters, we tried to calculate gravity values for each measurement. Because of very unsatisfactory results as evaluted by the consistency with the values measured by us in 1980 or 1984, we remeasured the gravity values at many points in Peru to use them as the reference when the gravity data reduction is carried out. Thus we determined each gravity values of IGP data set using least suares method.Terrain correction was made using DTM3 digital terrain model which covered whole South America. DTM3 has 3'x3' precision and we interpolated them to apply terrain correction program which is used in Japan with KS-110 terrain models having 250m x 250m precision.Finally we constructed a new Bouguer anomaly map over the whole Peru with terrain corrections. This is the very first Bouguer Anomaly map over the Peruvian Andes using revised IGP gravity data. This map and revised IGP gravity data are very important towards the understandings for the mountain building process of Pervian Andes.

我们提议开展一项联合研究，对秘鲁地理研究所 (IGP) 在过去 40 年中积累的重力数据进行处理。该项目的主要目标是由日本和秘鲁参与者进行各种研究，以便（a）从最基本的层面检查IGP重力数据集的正确性，（b）重复重力测量以获得准确的数据可以用作参考值，（c）进行实地调查以获得构造有趣区域的新重力剖面，以及（d）将所有可用数据编译成秘鲁布格异常地图并从 IGP 发布该地图。获得了从现场记录中获取 IGP 重力测量的原始读数并将其完全数字化。使用各个重力计的常数表，我们尝试计算每次测量的重力值。由于与我们1980年或1984年实测值的一致性评估结果很不理想，我们重新测量了秘鲁多处点的重力值，作为重力数据缩减时的参考。由此我们采用最小苏阿雷斯法确定IGP数据集的各个重力值。利用覆盖整个南美洲的DTM3数字地形模型进行地形修正。 DTM3 具有 3'x3' 精度，我们对它们进行插值以应用在日本使用的地形校正程序，使用精度为 250m x 250m 的 KS-110 地形模型。最后，我们在整个秘鲁构建了一个新的布格异常地图，并进行了地形校正。这是第一张使用修订后的 IGP 重力数据绘制的秘鲁安第斯山脉布格异常地图。这张地图和修订后的 IGP 重力数据对于了解安第斯山脉的造山过程非常重要。

项目成果

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志知龍一、山本明彦: "西南日本における重力データベースの構築" 地質調査所. 280. 1-28 (1994)

Ryuichi Shichi、Akihiko Yamamoto：“日本西南部重力数据库的建设”日本地质调查280. 1-28 (1994)。

Woodman, R. F.: "On the crue velocity in full correlation analysis" Radio Sci.30. 1459-1465 (1995)

Woodman, R. F.：“论全相关分析中的真实速度”Radio Sci.30。

Pickering, K. T., Underwood M. B., Taira, A., and Ashi, J.: "IZANAGI sidescan sonar and high-resolution multichannel seismic reflection line interpretation of Nanakai acretionary prism and trench, offshore Japan" Archtectural style in turbidite systems, 3

Pickering, K. T.、Underwood M. B.、Taira, A. 和 Ashi, J.：“日本近海 Nanakai 增生棱柱和海沟的 IZANAGI 侧扫声纳和高分辨率多道地震反射线解释”浊积岩系统中的建筑风格，3

大林政行・桜井太郎・深尾良夫: "走時インバージョンによるマントル3次元構造" 地学雑誌. 104. 934-940 (1995)

Masayuki Obayashi、Taro Sakurai 和 Yoshio Fukao：“通过走时反演得出地幔的三维结构”地质杂志 104. 934-940 (1995)。