Quantitative thickness estimation below tuning thickness is a great challenge in seismic exploration. Most studies focus on the thin-beds whose top and bottom reflection coefficients are of equal magnitude and opposit...Quantitative thickness estimation below tuning thickness is a great challenge in seismic exploration. Most studies focus on the thin-beds whose top and bottom reflection coefficients are of equal magnitude and opposite polarity. There is no systematic research on the other thin-bed types. In this article, all of the thin-beds are classified into four types： thin-beds with equal magnitude and opposite polarity, thin-beds with unequal magnitude and opposite polarity, thin-beds with equal magnitude and identical polarity, and thin-beds with unequal magnitude and identical polarity. By analytical study, an equation describing the general relationship between seismic peak frequency and thin-bed thickness was derived which shows there is a Complex implicit non-linear relationship between them and which is difficult to use in practice. In order to solve this problem, we simplify the relationship by Taylor expansion and discuss the precision of the approximation formulae with different orders for the four types of thin-beds. Compared with the traditional amplitude method for thin-bed thickness calculation, the method we present has a higher precision and isn＇t influenced by the absolute value of top or bottom reflection coefficient, so it is convenient for use in practice.展开更多
This paper studies the imminent anomalies observed by the Sacks volume strainmeter in Erzhangying station and Tiantanghe station before 80 earthquakes with Ms≥ 7. 0 which took place from January 2011 to April 2014 al...This paper studies the imminent anomalies observed by the Sacks volume strainmeter in Erzhangying station and Tiantanghe station before 80 earthquakes with Ms≥ 7. 0 which took place from January 2011 to April 2014 all over the world. Then, preconditions for anomaly identification are put forward for complex earthquake cases. Statistical results show that volume strain observation has a better earthquake reflecting ability for earthquakes with magnitudes larger than 7. 0 and epicentral distance within 8000kin. In addition, these results also reflect that the volume strain observation can better reflect precursory anomalies of such earthquakes. Based on categorization and description of those anomalies, we divide the anomalies into three types, that is, earth tide distortion type, abrupt change type and slow earthquake type. Furthermore, the paper makes a statistical analysis of these types and preliminarily discusses their mechanical properties as well. According to research, volume strain anomaly has an indicative significance to future strong earthquakes in the world.展开更多
Based on the data of 44 samples of hydrocarbon source rocks in Nanpu No.3 buffed-hill region, the kerogen type is judged through the pyrolysis and microscopic identification. At the same time, organic matter maturity ...Based on the data of 44 samples of hydrocarbon source rocks in Nanpu No.3 buffed-hill region, the kerogen type is judged through the pyrolysis and microscopic identification. At the same time, organic matter maturity and hydrocarbon generation threshold are studied by using vitrinite reflectance, pyrolysis yield and hydrocarbon abundance. Meanwhile the hydrocarbon expulsion threshold is calculated. And the characteristics of organic hydrocarbon generation and expulsion are preliminarily revealed and evaluated. The result shows that the No.3 buffed-hill region has abundant hydrocarbon source rocks with high content of organic carbon. And the primary types of kerogen are II, and lI 2. The hydrocarbon source rocks which passed biochemistry, thermolysis and thermal cracking have developed into the mature-postmature phase of different extents. And plenty of oil and gas were expelled out. It is believed the depth of oil-generating window is 3 600 m and the depth of hydro- carbon-expulsion threshold is 4 100 m. The comprehensive analysis indicates that Nanpu No.3 burried-hill region has a certain condition to generate hydrocarbon which is very promising in oil exploration and thus can become an important exploration and development target next.展开更多
This paper retrieves the bidirectional polarization distribution functions (BPDFs) of the distinct urban cover in the Pearl River Delta (PRD) region employing the high spatial resolution of multi-angle polarized measu...This paper retrieves the bidirectional polarization distribution functions (BPDFs) of the distinct urban cover in the Pearl River Delta (PRD) region employing the high spatial resolution of multi-angle polarized measurements made by the Directional Polarimetric Camera (DPC).The BPDF operational products of MICROPOL and POLDER measurements were used to validate the BPDF products of the DPC,with the results demonstrating that the BPDF product of the DPC measurements accurately expresses the surface polarized reflectance.The polarized reflectance of distinct surface types in the PRD region was studied using the DPC measurements.The results demonstrate that the polarized reflectances of different surface types differ and decrease as the normalized difference vegetation index increases.The polarized reflectance of a distinct surface type in the PRD region decreases with increasing scattering angle.The basic theory of investigating surface properties using multi-angle polarized measurements is proposed.展开更多
基金supported by National Key S&T Special Projects of Marine Carbonate 2008ZX05000-004CNPC Projects 2008E-0610-10
文摘Quantitative thickness estimation below tuning thickness is a great challenge in seismic exploration. Most studies focus on the thin-beds whose top and bottom reflection coefficients are of equal magnitude and opposite polarity. There is no systematic research on the other thin-bed types. In this article, all of the thin-beds are classified into four types： thin-beds with equal magnitude and opposite polarity, thin-beds with unequal magnitude and opposite polarity, thin-beds with equal magnitude and identical polarity, and thin-beds with unequal magnitude and identical polarity. By analytical study, an equation describing the general relationship between seismic peak frequency and thin-bed thickness was derived which shows there is a Complex implicit non-linear relationship between them and which is difficult to use in practice. In order to solve this problem, we simplify the relationship by Taylor expansion and discuss the precision of the approximation formulae with different orders for the four types of thin-beds. Compared with the traditional amplitude method for thin-bed thickness calculation, the method we present has a higher precision and isn＇t influenced by the absolute value of top or bottom reflection coefficient, so it is convenient for use in practice.
基金Combined project of monitoring,prediction and research of China Earthquake Administration entitled "Statistical study on the earthquake cases of imminent anomaly in Sacks volume strain measurements(154201)""Special Fund for Basic Scientific Research of Institute of Earthquake Science,CEA(2012IES010202)""Research on Regional Tectonic Stability for the Dateng Gorge Water Conservancy Hub Project Site(880456)"
文摘This paper studies the imminent anomalies observed by the Sacks volume strainmeter in Erzhangying station and Tiantanghe station before 80 earthquakes with Ms≥ 7. 0 which took place from January 2011 to April 2014 all over the world. Then, preconditions for anomaly identification are put forward for complex earthquake cases. Statistical results show that volume strain observation has a better earthquake reflecting ability for earthquakes with magnitudes larger than 7. 0 and epicentral distance within 8000kin. In addition, these results also reflect that the volume strain observation can better reflect precursory anomalies of such earthquakes. Based on categorization and description of those anomalies, we divide the anomalies into three types, that is, earth tide distortion type, abrupt change type and slow earthquake type. Furthermore, the paper makes a statistical analysis of these types and preliminarily discusses their mechanical properties as well. According to research, volume strain anomaly has an indicative significance to future strong earthquakes in the world.
文摘Based on the data of 44 samples of hydrocarbon source rocks in Nanpu No.3 buffed-hill region, the kerogen type is judged through the pyrolysis and microscopic identification. At the same time, organic matter maturity and hydrocarbon generation threshold are studied by using vitrinite reflectance, pyrolysis yield and hydrocarbon abundance. Meanwhile the hydrocarbon expulsion threshold is calculated. And the characteristics of organic hydrocarbon generation and expulsion are preliminarily revealed and evaluated. The result shows that the No.3 buffed-hill region has abundant hydrocarbon source rocks with high content of organic carbon. And the primary types of kerogen are II, and lI 2. The hydrocarbon source rocks which passed biochemistry, thermolysis and thermal cracking have developed into the mature-postmature phase of different extents. And plenty of oil and gas were expelled out. It is believed the depth of oil-generating window is 3 600 m and the depth of hydro- carbon-expulsion threshold is 4 100 m. The comprehensive analysis indicates that Nanpu No.3 burried-hill region has a certain condition to generate hydrocarbon which is very promising in oil exploration and thus can become an important exploration and development target next.
基金supported by the National Basic Research Program of China(Grant No.2010CB950800)the National Natural Science Foundation of China(Grant No.41001207)the Funds of the Chinese Academy of Sciences for Key Topics in Innovation Engineering(Grant No.KZCX2-EW-QN311)
文摘This paper retrieves the bidirectional polarization distribution functions (BPDFs) of the distinct urban cover in the Pearl River Delta (PRD) region employing the high spatial resolution of multi-angle polarized measurements made by the Directional Polarimetric Camera (DPC).The BPDF operational products of MICROPOL and POLDER measurements were used to validate the BPDF products of the DPC,with the results demonstrating that the BPDF product of the DPC measurements accurately expresses the surface polarized reflectance.The polarized reflectance of distinct surface types in the PRD region was studied using the DPC measurements.The results demonstrate that the polarized reflectances of different surface types differ and decrease as the normalized difference vegetation index increases.The polarized reflectance of a distinct surface type in the PRD region decreases with increasing scattering angle.The basic theory of investigating surface properties using multi-angle polarized measurements is proposed.
