Study of mountain uplifting mechanism of Peruvian Andes

秘鲁安第斯山脉抬升机制研究

• 批准号: 09041097
• 负责人: FUKAO Yoshio
• 金额: $ 8.58万
• 依托单位: The 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: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09041097/
• 关键词: Andes; gravity; Peru; Bouguer correstion; gravimeter; 火山岩層; 地質; IGP; 枕状溶岩; 堆積層; 断層

We collected all the data of gravity measurements carried out over the last 40 years by Instituto Geofisico del Peru (IGP). Because of long time since the data collection, some of the important information needed for data reduction were lost in the mean time. For instance, it is not quite certain which constant table among several were applied to a particular to a particular survey conducted with a certain gravimeter. There were also other difficulties caused by the nature of the IGP dataset which became apparent to us in the course of conversion of the original data to gravity values. An example of this kind is that the measurement usually started at some point on the survey route and ended at another, so that it is difficult to find gravity stations correlatable to known references. Because of these problems, it was impossible to determine the gravity values unambiguously from the IGP data alone. Accordingly, there was a need for independently determined gravity stations to which the measurements done by IGP may be compared. In order to provide reference gravity values, we recalibrated the Japanese survey data obtained in 1980 and 1984, and conducted more surveys in various parts of Peru during the period from 1995 to 1998. These gravity stations number more than 800, and provide three or more reference points for each of the IGP survey routes. Using these references, the gravity values were calculated for the IGP dataset and Bouguer corrections were applied. Finally we established more than 10,000 gravity values in all survey routes and a Bouguer anomaly map of whole Peru was successfully produced based on these data.

我们收集了秘鲁地理研究所 (IGP) 在过去 40 年中进行的所有重力测量数据。由于数据采集时间较长，数据缩减所需的一些重要信息同时丢失。例如，对于使用特定重力计进行的特定调查，不太确定几个常数表中的哪一个适用于特定的情况。 IGP 数据集的性质还带来了其他困难，这些困难在将原始数据转换为重力值的过程中变得显而易见。这种类型的一个例子是，测量通常从测量路线上的某个点开始并在另一个点结束，因此很难找到与已知参考相关的重力站。由于这些问题，仅根据 IGP 数据无法明确确定重力值。因此，需要独立确定的重力站来与 IGP 进行的测量进行比较。为了提供参考重力值，我们重新校准了1980年和1984年获得的日本测量数据，并在1995年至1998年期间在秘鲁各地进行了更多的测量。这些重力站数量超过800个，并提供三个或更多每条 IGP 调查路线的参考点。使用这些参考，计算 IGP 数据集的重力值并应用布格校正。最终我们在所有测量路线上建立了10000多个重力值，并根据这些数据成功制作了整个秘鲁的布格异常图。

项目成果

Yamamoto, A., Saito, Y.Fukao et al.: "Construction of Gravity Anomaly Map of Whole Peru" Bull.Earthq.Res.Inst.(in press). (1998)

Yamamoto, A.、Saito, Y.Fukao 等人：“整个秘鲁重力异常图的构建”Bull.Earthq.Res.Inst.（正在印刷中）。

Suda, N., N. Nawa and Y. Fukao: "Earth's background free oscillations"Science. 279. 2089-2091 (1998)

Suda, N.、N. Nawa 和 Y. Fukao：“地球背景自由振荡”科学。

Yamamoto, A.: "Estimation the optimum reduction density forgravity anomaly: A theoretical overview"Ja. Fac. Sci., HokkaidoUniv.. 11. 577-599 (1999)

Yamamoto, A.：“估计重力异常的最佳还原密度：理论概述”Ja。

Kono.M.: "Distribution of paleomagnetic directions and poles" Phys.Earth Planet.Inter.103. 313-327 (1997)

Kono.M.：“古地磁方向和磁极的分布”Phys.Earth Planet.Inter.103。

Yamamoto, A.: "Estimating the optimum reduction density forgravity anomaly : A theoretical overview"J. Fac. Sci., Hokkaido Univ.. 11. 577-599 (1999)

Yamamoto, A.：“估计重力异常的最佳还原密度：理论概述”J。