期刊文献+
共找到6篇文章
< 1 >
每页显示 20 50 100
Characteristics of gravity anomalies and prediction of volcanosedimentary boron deposit distribution in the Xiongba area,Tibet 被引量:2
1
作者 宋丽蓉 于常青 +2 位作者 李桂花 冯杨洋 何俊杰 《Applied Geophysics》 SCIE CSCD 2015年第4期516-522,627,共8页
Volcanosedimentary boron deposits are present within Tertiary lacustrine sediments and volcanic rocks in Xiongba, Tibet. Boron deposits are characterized by low density relative to country rocks; thus, it is possible ... Volcanosedimentary boron deposits are present within Tertiary lacustrine sediments and volcanic rocks in Xiongba, Tibet. Boron deposits are characterized by low density relative to country rocks; thus, it is possible to locate them by gravity measurements. We conducted a 1:50000 high-precision gravity survey in the Xiongba area, Tibet, and obtained the Bouguer and residual gravity anomalies. We analyzed fault systems and the distribution of sedimentary and volcanic rocks and their relation to the volcanosedimentary boron deposits. The processing of the gravity data revealed local gravity variations and fault structures. We applied preferential downward continuation and wavelet transform to the gravity data, and in conjunction with geological data, we predicted the distribution of volcanosedimentary boron deposits. 展开更多
关键词 Volcanosedimentary boron deposits gravity survey preferentialwavelet transform
下载PDF
Spherical External Gravity Correction 被引量:4
2
作者 杨战军 柴玉璞 《Applied Geophysics》 SCIE CSCD 2005年第3期131-134,i0001,共5页
In mountainous area, gravity survey external corrections, including terrain and Bouguer corrections, are the prerequisites for gravity data processing and interpretation. This paper presents a suite of techniques for ... In mountainous area, gravity survey external corrections, including terrain and Bouguer corrections, are the prerequisites for gravity data processing and interpretation. This paper presents a suite of techniques for spherical terrain and slab corrections for a finite spherical shell based on the analysis of conventional external corrections and deduces an equation for spherical terrain correction. The processing of gravity data acquired in the ZJJ area, South China shows that this technique significantly improves the accuracy of terrain corrections, and the quality of the data reaches or approaches the data acquired on plains. 展开更多
关键词 mountainous area gravity survey spherical external correction
下载PDF
High-precision gravity correction methods for loess plateau areas, a case study 被引量:1
3
作者 Ji Liansheng Zheng Li 《Applied Geophysics》 SCIE CSCD 2007年第2期89-93,共5页
The loess plateau is featured by a sharply undulated and remarkably incised surface. The sharp surface undulation means great variation of loess thickness. Since the loess layer exhibits significant density contrast w... The loess plateau is featured by a sharply undulated and remarkably incised surface. The sharp surface undulation means great variation of loess thickness. Since the loess layer exhibits significant density contrast with the underlying formation, a high frequency gravity anomaly with a certain magnitude will appear. The high frequency gravity anomaly can result in some difficulties for processing and interpreting the gravity data, thereby reducing the usefulness of gravity surveys in loess plateau areas. We carried out a high precision gravity survey in the SHJZ structural zone. During data processing, we applied terrain and loess corrections to effectively remove or suppress the gravity effect resulting from surface undulation and variation of loess thickness. We obtained high precision gravity data which matches well with other geophysical data. The comprehensive interpretation based on the final gravity data help to study local structure integrated with other published geophysical data. 展开更多
关键词 high precision gravity survey gravity anomaly DENSITY loess correction terrain correction
下载PDF
A marine gravimeter based on electromagnetic damping and its tests in the South China Sea 被引量:1
4
作者 Pengfei WU Lin WU +3 位作者 Lifeng BAO Long WANG Bo WANG Danling TANG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第2期792-803,共12页
A new gravity sensor based on electromagnetic damping for the JMGrav marine gravimeter is presented.The new gravity sensor considered the advanced construction methods of the electromagnetic damping system of the grav... A new gravity sensor based on electromagnetic damping for the JMGrav marine gravimeter is presented.The new gravity sensor considered the advanced construction methods of the electromagnetic damping system of the gravimeter.The design features of the new system are discussed and the research survey data in the South China Sea are shown.Numerical simulations are applied to model the magnetic and mechanical characteristics of the system using finite element analysis and to evaluate the force distribution and the resulting damping effects.The performance characteristics of the system were tested on a motion simulator in laboratory,and the gravimeter was subjected to vertical accelerations of up to 100 Gal in 1-1000 s.It was found that the amplitude reduction of vertical accelerations in 3-15 s is 30-45 dB,with a time lag of 2-5 s,while the effect on gravity in period greater than 600 s is less than 0.5 dB,with a time lag of less than 100 s.The accelerations cause discrepancies of approximately only 1 mGal between the static value and the mean dynamic value.The sea tests were conducted in September 2020.Gravity measurements were taken with a JMGrav marine gravimeter onboard the R/V Dongfanghong 3,and the effective survey line exceeded 2000 km.Completely irregular accelerations with peaks up to 100 Gal yielded a reduction of approximately 40 dB in amplitude.The survey data were evaluated using ocean gravity field models and grid line tests.The results show that the accuracy of the gravity measurements is better than 2 mGal. 展开更多
关键词 electromagnetic damping JMGrav marine gravimeter marine gravity survey
下载PDF
Preliminary Analysis for Ground Structure around Source Region of 2008 Iwate-Miyagi Nairiku Earthquake
5
作者 Hitoshi Morikawa Masachika Tanigawa +1 位作者 Taiyo Kobayashi Hiroko Matsuo 《Journal of Civil Engineering and Architecture》 2011年第2期175-179,共5页
To obtain a detailed model of the three-dimensional ground structure, the microtoremor and gravity surveys were carried out around Kurikoma area, Japan, where is the source reagion of 2008 Iwate-Miyagi nairiku earthqu... To obtain a detailed model of the three-dimensional ground structure, the microtoremor and gravity surveys were carried out around Kurikoma area, Japan, where is the source reagion of 2008 Iwate-Miyagi nairiku earthquake and is located about 90 km north of Sendai. Using the microtremor data, velocity structures of shallow sediments are estimated and the results at some of the sites are reported preliminarily. We could not find the detailed velocity structure to bedrock, because small arrays for the microtremor observation were applied, However, significant structures are observed for shallow velocity structure at some sites. Furthermore, gravity data provided Bouguer anomaly, which is one of gravity anomalies, around the target area. From the Bouguer anomaly, area with low anomaly is tbund around the south-eastern area of the fault plane. 展开更多
关键词 gravity survey microtremor array observation ground structure 2008 Iwate-Miyagi Nairiku Earthquake.
下载PDF
Comparison of Absolute Gravity Measurements Obtained with FG5/232 and FG5/214 Instruments 被引量:23
6
作者 XING Lelin LI Hui +1 位作者 LI Jiancheng HE Zhitang 《Geo-Spatial Information Science》 2009年第4期307-310,共4页
This paper introduces the comparison of absolute gravity measurements in China during 2006-2008,and analyzing the survey and comparing the results,it shows that there is no obvious system error between the gravimeter ... This paper introduces the comparison of absolute gravity measurements in China during 2006-2008,and analyzing the survey and comparing the results,it shows that there is no obvious system error between the gravimeter of FG5/214 and FG5/232,the surveying accuracy is very high and repetition is good,and their inner surveying accuracy is about 2-3 microGal. 展开更多
关键词 COMPARISON absolute gravity surveying gravity change EARTHQUAKE
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部