地震地质 ›› 2023, Vol. 45 ›› Issue (5): 1147-1169.DOI: 10.3969/j.issn.0253-4967.2023.05.007

• 研究论文 • 上一篇    下一篇

大别山金寨重力基线场混合重力测量试验与分析

徐如刚1,2,3)(), 张新林4)(), 梁霄1), 孙鸿博1), 储飞1), 黄显良1,3), 谈洪波4), 汪健4)   

  1. 1) 安徽省地震局, 合肥 230031
    2) 中国科学技术大学, 地球和空间科学学院, 合肥 230026
    3) 安徽蒙城地球物理国家野外科学观测研究站, 蒙城 233500
    4) 中国地震局地震研究所, 武汉 430071
  • 收稿日期:2022-11-07 修回日期:2022-12-28 出版日期:2023-11-23 发布日期:2023-11-23
  • 作者简介:

    徐如刚, 男, 1980年生, 2007年于中国地震局地震研究所获固体地球物理学专业硕士学位, 高级工程师, 主要从事重力数据处理与反演研究, E-mail:

    张新林, 男, 1980年生, 助理研究员, 主要从事重力观测数据解释和地震位错理论研究, E-mail:

    共同第一作者

  • 基金资助:
    蒙城地球物理国家野外科学观测研究站联合开放基金(MENGO202107); 蒙城地球物理国家野外科学观测研究站联合开放基金(MENGO202310); 中国地震局地震科技星火计划项目(XH19019Y); 安徽省“十三五”防震减灾重点项目和国家自然基金面上项目(42074172)

ANALYSIS FOR SYNTHETIC ADJUSTMENT OF ABSOLUTE AND RELATIVE GRAVITY OF JINZHAI GRAVITY BASELINE IN DABIE MOUNTAIN

XU Ru-gang1,2,3)(), ZHANG Xin-lin4)(), LIANG Xiao1), SUN Hong-bo1), CHU Fei1), HUANG Xian-liang1,3), TAN Hong-bo4), WANG Jian4)   

  1. 1) Anhui Earthquake Agency, Hefei 230031, China
    2) School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China
    3) Anhui Mengcheng National Geophysical Observatory, Mengcheng 233500, China
    4) Institute of Seismology, China Earthquake Administration, Wuhan 430071, China
  • Received:2022-11-07 Revised:2022-12-28 Online:2023-11-23 Published:2023-11-23

摘要:

在地震重力区域监测网数据处理过程中, 相对重力仪的格值标定和基准控制通常采用本网内的绝对重力基准值, 由于仪器格值和控制基准的影响相互耦合, 难以定量分析格值、 基准控制对测网数据平差处理的影响。文中基于大别山金寨重力基线场的混合重力测量数据, 解耦了格值、 基准控制的影响, 获得了金寨重力基线场的初值。结果表明: 金寨重力基线场可以满足安徽地震重力测网仪器标定的需求, 对提升监测效率、 节约经济成本具有重要意义, 也可为其他基线场、 地震重力区域监测网数据处理提供参考。

关键词: 混合重力测量, 格值, 基准控制, 金寨重力基线场, 大别山

Abstract:

In the data process of the regional gravity monitor network, the absolute gravity reference value is the control datum of the gravity monitor network and is usually used for calibrating the scale of the relative gravimeter. Due to the coupling influence of the gravimeter scale and the control datum, it is difficult to quantitatively analyze their influence of on the adjustment processing of the regional gravity monitor network data.

Based on the hybrid gravity observation data of the Jinzhai gravity baseline field in Dabie Mountain, the paper decouples the influence of the relative gravimeter scale and gravimetry control datum. According to analyzing the average point value, the point value, section difference, and the accuracy, we obtain the influence of the gravimeter scale and control datum on data processing of the regional gravity monitor network. The initial gravity value of the Jinzhai gravity baseline corresponds to the optimal combination of the gravimeter scale and control datum and the following conclusions are obtained:

(1)The results of the mutual difference of gravimeters, section difference, and their accuracy calculated by different combinations of gravimeter scale and control datum show that the control datum is of great significance to reduce the inter-difference between gravimeters and obtain reliable measurement results, and the control datum used to the gravimeter scale calibration should form a complete coverage of the reading range of the regional gravity monitor network.

(2)Gravity point values and their accuracy of the Jinzhai gravity baseline calculated by the different combinations of gravimeter scale and control datum show that the point values and accuracy are both affected by the gravimeter scale and control datum. When the solution point is located at the end of the control datum and the solution point is used as the control datum and participates in the solution calculation, the influence of the control datum and gravimeter scale on the solution is the same. When the solution point is not used as the control datum to participate in the solution control, the influence of the gravimeter scale on the solution is stronger than the control datum. When the solution points are between the control datum, the influence of the control datum on the solution is stronger than the gravimeter scale, and the more control points participate, the stronger the influence of the control datum on the solution.

(3)Using the all control data which fully cover the reading range of the measuring network and its corresponding gravimeter scale to resolve the observation data, the point value has the highest accuracy. The solution obtained by a combination of the end control datum and its corresponding gravimeter scale is the second. The accuracies of other references and scale combinations are equivalent and the lowest. The points between the reference are strongly controlled, while the points out of the reference, the farther from the reference, the weaker the control, and the lower the point value accuracy which shows a monotone linear increase.

(4)The data adjustment results of the Jinzhai gravity baseline based on the optimal gravimeter scale and control datum combination show that the accuracies of the section difference are better than 2μGal, and the average accuracy of the point value is better than 2.8μGal. The accuracies of the observation data of the three absolute gravity stations are better than 2.0μGal, and the accuracies about the section difference of the gravity vertical gradient are better than 1.0μGal. The results satisfy the project requirements and can be formally adopted.

(5)The analysis of the difference between scale WYB and the optimal scale 123 shows that the gravimeter scales calibrated in the same reading section can be used directly with each other.

(6)The Jinzhai gravity baseline can meet the requirements of gravimeter calibration for the gravity monitor network of Anhui. The construction and application of the Jinzhai gravity baseline are of great significance to improve monitoring efficiency and save economic cost. The data processing and analysis method of the Jinzhai gravity baseline field can also provide a reference for data processing of other baseline fields and regional gravity monitor networks. The Jinzhai gravity baseline extended to the absolute gravity point with a larger section difference can meet the gravimeter calibration requirements of the gravity monitor network with a larger gravity segment difference.

Key words: Hybrid gravity measurement, Scale, Reference control, Jinzhai gravity baseline, Dabie Mountain