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51.
52.
利用卫星遥感资料对南海北部陆架海洋表层温度锋的分析 总被引:4,自引:0,他引:4
利用7年(1993~1999)月平均的SST卫星遥感资料,分析了南海北部陆架区域海洋表层温度锋在一年中的逐月变化特征,表明南海北部陆架海洋表层温度锋存在明显的季节内变化。结合风场的卫星遥感资料,分析了东北季风对南海北部陆架温度锋的影响,表明东北季风风速的增加有利于温度锋强度的增强。通过对黑潮南海流套入侵较强的1999年2月与流套入侵较弱的1998年2月的SST卫星遥感资料的对比分析,考察了黑潮南海流套的入侵对南海北部陆架温度锋的影响,结果表明黑潮流套的较强入侵能够增加陆架温度锋的强度,对温度锋的走向也会产生一定的影响。 相似文献
53.
Mingqiang Fang 《Journal of Oceanography》2006,62(5):759-766
This study reveals the physical backgrounds of the geometric centroid and the thermal centroid of the Western Pacific Warm Pool (WPWP) and points out their differences. The geometric centroid (actually a very close approximation to the mass centroid) anomaly of the surface WPWP correlates more closely with the Niño-3 region sea surface temperature anomaly (Niño-3 SSTA, an important indicator of El Niño/La Niña events) than the surface thermal centroid. Taking the WPWP depth (or heat storage) into account, the “real” mass or thermal centroid of the WPWP might correlate better with the El Niño/Southern Oscillation (ENSO) signals. 相似文献
54.
Apatite fission-track (AFT) thermochronological modeling as a diagnostic tool for periods of stability (peneplanation) and tectonic activity (orogeny) has been broadly used in tectonic studies of Central Asia in recent years. We discuss more than 100 AFT ages of samples from the Kyrgyz Tien Shan and Altai and compare them with AFT data from northern Kazakhstan. Geological, geomorphological, and AFT data indicate intense activity in the Late Cenozoic Eurasian continental interior. The impact from the India-Eurasia collision on the northern Tien Shan, Altai, and northern Kazakhstan regions showed up at 11, 5, and 3 Ma, respectively, as a result of stress propagation into the continent, with the ensuing reactivation and mountain growth. We hypothesize that a distant effect of the Late Cenozoic India-Eurasia collision was to rejuvenate Paleozoic fault zones and to deform the Mesozoic sedimentary cover north of the collision front as far as the West Siberian Plate. The reactivation facilitated formation of tectonic oil and gas traps. The activity in northern Central Asia under the effect of the Indian indentation into Eurasia appears to continue and may evolve to include uplift of southern West Siberian plate with uplift. 相似文献
55.
震前卫星热红外环形应力场特征 总被引:6,自引:1,他引:5
本文包括两部分内容:①描述了1996年2月3日云南丽江Ms7.0级地震,震前几天的卫星热红外图像呈现圆形,它的NNW、NW、SN、及NE向的热旋扭面往S收敛。该地震地表破裂由一系列张扭性裂缝组成,呈左旋左列,水平位错不明显,垂直断距数厘米。垂直力对构造变动的作用较为明显;而丽江地震震源机制解破裂面II的走向NNE6o,倾向W,倾角44o,P轴方位为NNE3o、仰角75o,近于直立,综合热旋扭面展布、地震地表破裂特征及震源机制解,得出该旋扭椭圆为地幔外侧右旋上涌所造成;②菲律宾萨马岛Ms7.0~7.5强震群及青海共和Ms7.0地震前热应力环椭圆的推进路径。根据这一特征得出交变潮汐力的地球动力学解释。卫星热红外图像震前应力热场的方法是临震预测地震的有效方法,卫星热红外技术辅以震源机制解和地表破裂带力学分析是研究地球动力学有力工具。地球自转速度变化,交变潮汐力和地幔旋扭上涌力是地球动力学的主因。 相似文献
56.
Taeko Shinonaga Helmuth Aigner Dilani Klose Peter Spinder Heinz Fröschl David Donohue 《Geostandards and Geoanalytical Research》2008,32(1):93-101
The recommended concentrations of 239Pu, 240Pu and 239+240Pu in reference material IAEA‐315 (marine sediment) were estimated by three analytical methods: isotope dilution thermal ionisation mass spectrometry (TIMS), isotope dilution inductively coupled plasma‐mass spectrometry (ICP‐MS) and alpha spectrometry. The determination of 239Pu and 240Pu (239+240Pu by alpha spectrometry) was carried out with samples from randomly selected bottles using each method. Plutonium‐238 was also measured by alpha spectrometry. A plutonium‐242 reference material was used as a spike for the quantitative analysis. The influence of 242Pu in the samples was therefore calculated; however, this contribution was less than the range of uncertainty and did not influence the final results. The obtained data were statistically analysed using variance component analysis and paired comparison. The combined standard uncertainties from “method/measurement”, “bottle” and “sub‐sample” were in the order of 3 to 6%. The main contributions to the uncertainty were from the material heterogeneity and from systematic differences between methods. Based on this study with twenty‐seven analyses using 10–14 g sample mass, concentrations of (38 ± 3) Bq kg?1, (28 ± 3) Bq kg?1 and (66 ± 4) Bq kg?1 are proposed as recommended values for 239Pu, 240Pu and 239+240Pu, respectively, and (9.5 ± 0.4) Bq kg?1 for 238Pu as an information value in reference material IAEA‐315. In mass concentration units, these amount to (16.4 ± 1.2) ng kg?1, (3.3 ± 0.4) ng kg?1 and (0.015 ± 0.003) ng kg?1 for 239Pu, 240Pu and 238Pu, respectively. The certified reference materials NIST 4350B and NIST 4354 were also analysed by TIMS for quality assurance of the method used in this study. 相似文献
57.
利用傅立叶变换红外光谱(FTIR)分析技术,对乌达矿区低温氧化和新鲜煤样进行了红外光谱测试,通过两类煤样的特征官能团吸光度的对比分析.揭示了煤在氧化前后特征官能团的变化规律:氧化后的煤样中脂肪族和芳烃CH减少,酸酐C=O从无到有,芳烃骨架C=C基本不变,进而研究了其对煤自燃倾向性的影响。结果表明脂肪族和羟基含量越高,煤自燃倾向性越大。 相似文献
58.
J. B. W. Day 《Environmental Geology》1996,27(2):77-78
Predictably, in a country such as Britain, with its preponderance of consolidated, sedimentary, mainly fissure-flow aquifers, there is a very large number of springs, many of which are, or have been, used for public supply. Migratory springs are a feature of the British (Ur. Cretaceous) Chalk, the most important British aquifer. The Chalk's low specific yield and high capillary moisture retention together give rise to very considerable fluctuations (more than 33 m in some areas) of the unconfined water table. Along the gentle dip slopes of the Chalk (North and South Downs of southern and southeastern England) springs may migrate laterally for several miles, giving rise to seasonal streams locally known as bournes or lavants. However, springs such as at Duncton, West Sussex, at the base of the much steeper scarp slopes of the Chalk, form point sources, the flows from which tend to be relatively steady; such springs commonly supply and are the original reason for the existence of many of the small towns and villages which nestle along the bases of the chalk scarps of Sussex and Kent.Where the Chalk forms coastal cliffs, a number of springs break out at the base of the cliff between high and low tide levels; there are major chalk coastal springs, for instance, at St. Margaret's Bay (Kent) and at Arish Mells, east of Lulworth Cove, Dorset. Such springs are not used for direct supply (their salinity is usually too high) but are indicators of the presence of local reserves of groundwater for possible future development. 相似文献
59.
We have obtained infrared colors and limiting magnitudes from 1.25–4.8µm for a sample of 26 of the cm continuum radio sources located in the core of the Oph molecular cloud. Their colors demonstrate that the majority of the sources appear to be heavily reddened objects surrounded by circumstellar accretion disks. In these cases the radio emission most likely diagnoses accretion driven energetic outflow phenomena: either ionized winds or possibly synchrotron emission from shocked gas associated with stellar jets. 相似文献
60.
为研究天环坳陷北段下古生界天然气成藏规律,利用探井资料和有机地球化学方法,评价了天环坳陷北段奥陶系烃源岩特征并恢复其成熟演化史。天环坳陷北段奥陶系乌拉力克组和克里摩里组烃源岩有机碳含量和生烃潜量相对较高,烃源岩有机质丰度以中等—好为主,少部分为差烃源岩;三道坎组和桌子山组烃源岩以差为主。干酪根组分鉴定表明,天环坳陷北段奥陶系烃源岩主要为Ⅱ1~Ⅰ型干酪根,热演化程度高,处于生干气阶段。成熟演化史模拟显示,古生代—中生代早期地温梯度低,地层埋藏浅,烃源岩成熟演化程度低。燕山期,由于构造热事件,地温梯度迅速升高,早白垩世烃源岩经历的最高温度超过200℃,达到生气高峰期,早白垩世是油气成藏的主要时期。早白垩世之后,鄂尔多斯盆地整体抬升,地温梯度减小,生烃作用停止。 相似文献