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本文利用WRF模式及其伴随模式研究了2005年发生在西北太平洋的一对双台风玛娃和古超的移动路径与强度的伴随敏感性特征,一方面探讨了环境场对双台风的影响,另一方面也讨论了双台风之间的相互影响过程的差异.首先,利用双台风初始化技术准确地模拟了双台风的演变过程,并以此模拟结果为背景场计算了台风的中心扰动气压和引导气流的伴随敏感性.研究结果表明：伴随敏感性不但能反映环境场对双台风的影响,还能指示双台风之间相互影响过程的差异.从台风强度的敏感性来看,影响台风强度变化的高影响区均位于台风中心附近,弱台风古超的强度敏感性的量级要大于强台风玛娃的强度敏感性,表明双台风中较弱的那个更容易受到外部环境变化的影响.台风引导气流的敏感性分布也存在较大差异,强台风玛娃的移动主要受到其西北侧的高空槽,其自身环流以及台风古超的影响,而弱台风古超的引导气流的敏感性主要位于其自身环流附近以及双台风之间的区域.最后,通过在理想试验中增加初始时刻高空槽的强度以及弱台风古超的强度,证实了台风玛娃的移动路径的变化与伴随敏感性的分析一致. 相似文献
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Christopher J. Hutton 《地球表面变化过程与地形》2014,39(11):1559-1562
The pervasive application of the Null Hypothesis Significance Test in geomorphic research runs counter to widespread, long running, and often severe criticism of the method in the broader scientific literature. The application of the methodology typically leads to a binary separation of evidence into ‘significant’ and ‘not significant’ results based on a p‐value that is dependent on the null hypothesis being true. The method should not therefore be used to provide statistical support for substantive hypotheses, and is unsuitable for scientific inference in open systems where confirmation can only ever be partial. Alternative approaches based on Bayesian statistics can importantly be applied to measure partial support for hypotheses, conditional on the available data. Though not without their own assumptions, wider application of such methods can help facilitate a transition towards a broader approach to statistical, and in turn, scientific inference in geomorphic systems. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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阿尔金超高压(>7 GPa)片麻状(含)钾长石榴辉石岩 总被引：1，自引：0，他引：1
岩相学和矿物化学研究表明, 阿尔金英格利萨依一带片麻状(含)钾长石榴辉石岩中的粗粒石榴子石出溶单斜辉石和金红石. 统计石榴子石出溶的单斜辉石的面积比最高>5%, 重建出溶前该石榴子石(Grt1)单位分子式中的Si值高达3.061, 为含Na的超Si-石榴石或含有majorite分子的石榴子石. 依据石榴子石含辉石摩尔体积压力计和majoritic-石榴子石 Si-(Al+Cr)压力计估算其峰期变质压力>7 GPa, 利用三元碱性长石温度计和钛铁矿-磁铁矿固溶体的实验资料获其形成温度约1000℃. 同时, 结合其原岩具有板内基性与中性火成岩及其可能是源于大陆岩石圈地幔的基性岩浆演化产物的地球化学特征, 以及与其伴生的超高压石榴子石二辉橄榄岩的发现和超高压含石榴子石花岗质片麻岩的研究, 不仅证明区内超高压岩石的形成是陆壳深俯冲作用的产物, 而且表明这种深俯冲可能达到>200 km的地幔深处. 这对深入探讨阿尔金乃至中国西部碰撞造山带形成与演化的动力学机制提供了新的证据. 相似文献
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根据先前相似模型实验的结果 ,在板块边界驱动下 ,沿岩石圈下层 (含下地壳和岩石圈地幔 )传播的塑性流动波包括“快波”和“慢波” ,二者均属于黏性重力波 ,并分别由主波和辅波叠加而成。“快波”以 10 0 ～ 10 2 km/a量级的速度传播 ,已为塑性流动波控制下地震迁移的研究所证实。文中根据 7级以上强震的条带状分布图像 ,证明在喜马拉雅弧驱动下还存在着波速仅为 10 0 ～ 10 1m/a量级的“慢波” ,其中对 7级以上强震起控制作用的主要是“慢波”的辅波 ,其平均波长为 4 45km ,波速为 0 81～ 2 80m/a ,周期为 0 .16～ 0 .5 5Ma。“慢波”的边界起波时间距今约 1.34～ 4 .6 6Ma ,相当于上新世中期至早更新世中期 ,与喜马拉雅构造运动的主要活跃期 (幕 )之一相吻合。以喜马拉雅弧西段和东段为波源所形成的2个“慢波”系统的波峰带相互重叠 ,为 7级以上强震的发生提供了必要的能量背景 相似文献
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《世界地震译丛》2016,(1)
建筑规范中,地表到地下30m深度的走时平均剪切波速度[VS(30)]是场地分类的重要参数。利用在两个不同深度[VS(z1)和VS(z2),且z1z230m]下得到的走时平均剪切波速度,提出了用井孔中测量的浅层剪切波速度剖面估计VS(30)的新方法。选用剪切波速度剖面达30m的日本KiK-net台网594个井孔和美国加利福尼亚州的135个井孔的数据,通过VS(30)实测值与VS(30)估计值之间的相关性和用VS(30)估算值给出场地分类的准确性验证了该新方法的可靠性。结果显示,该方法可以提高VS(30)的准确度,且VS(30)的实测值与估算值之间的皮尔逊相关系数等于0.999,VS(30)的估算值给出的场地分类准确率大于96%,而z1≥10m,z2=25m。利用来自日本的数据研究了VS(z)的实测值与估算值在6个不同深度(50,100,150,200,400,600m)时的相关性,结果表明当所选的两个深度(z1,z2)接近某个深度z时,利用该假设方法估算的VS(z)(z≥50m)的准确度有所提高。相比Boore(2004)和Boore等(2011)的方法,新方法不需要对大量场地做回归分析以获得经验关系,没有区域性依赖,准确度有显著提高,且在世界的许多地方均有潜在的用途。 相似文献
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Olga V. Pavlenko 《Journal of Seismology》2016,20(3):803-826
To understand physical mechanisms of generation of abnormally high peak ground acceleration (PGA; >1g) during the Tohoku earthquake, models of nonlinear soil behavior in the strong motion were constructed for 27 KiK-net stations located in the near-fault zones to the south of FKSH17. The method of data processing used was developed by Pavlenko and Irikura, Pure Appl Geophys 160:2365–2379, 2003 and previously applied for studying soil behavior at vertical array sites during the 1995 Kobe (М w ?=?6.8) and 2000 Tottori (М w ?=?6.7) earthquakes. During the Tohoku earthquake, we did not observe a widespread nonlinearity of soft soils and reduction at the beginning of strong motion and recovery at the end of strong motion of shear moduli in soil layers, as usually observed during strong earthquakes. Manifestations of soil nonlinearity and reduction of shear moduli during strong motion were observed at sites located close to the source, in coastal areas. At remote sites, where abnormally high PGAs were recorded, shear moduli in soil layers increased and reached their maxima at the moments of the highest intensity of the strong motion, indicating soil hardening. Then, shear moduli reduced with decreasing the intensity of the strong motion. At soft-soil sites, the reduction of shear moduli was accompanied by a step-like decrease of the predominant frequencies of motion. Evidently, the observed soil hardening at the moments of the highest intensity of the strong motion contributed to the occurrence of abnormally high PGA, recorded during the Tohoku earthquake. 相似文献
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D. Rouwet Y. Taran S. Inguaggiato N. Varley J.A. Santiago Santiago 《Journal of Volcanology and Geothermal Research》2008
El Chichón volcano (Chiapas, Mexico) erupted violently in March–April 1982, breaching through the former volcano–hydrothermal system. Since then, the 1982 crater has hosted a shallow (1–3.3 m, acidic (pH ∼ 2.2) and warm (∼ 30 °C) crater lake with a strongly varying chemistry (Cl/SO4 = 0–79 molar ratio). The changes in crater lake chemistry and volume are not systematically related to the seasonal variation of rainfall, but rather to the activity of near-neutral geyser-like springs in the crater (Soap Pool). These Soap Pool springs are the only sources of Cl for the lake. Their geyser-like behaviour with a long-term (months to years) periodicity is due to a specific geometry of the shallow boiling aquifer beneath the lake, which is the remnant of the 1983 Cl-rich (24,000 mg/l) crater lake water. The Soap Pool springs decreased in Cl content over time. The zero-time extrapolation (1982, year of the eruption) approaches the Cl content in the initial crater lake, meanwhile the extrapolation towards the future indicates a zero-Cl content by 2009 ± 1. This particular situation offers the opportunity to calculate mass balance and Cl budget to quantify the lake–spring system in the El Chichón crater. These calculations show that the water balance without the input of SP springs is negative, implying that the lake should disappear during the dry season. The isotopic composition of lake waters (δD and δ18O) coincide with this crater lake-SP dynamics, reflecting evaporation processes and mixing with SP geyser and meteoric water. Future dome growth, not observed yet in the post-1982 El Chichón crater, may be anticipated by changes in lake chemistry and dynamics. 相似文献
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《中国地震研究》2014,(2)
The ancient idea of Heavenly Punishment confused natural phenomena with social issues,which resulted in Zhang Heng’s tragedy in his later years and seismoscope. The instrument might have been lost in the end of the Eastern Han Dynasty. A series of extremely serious chaotic social events caused by war took place,such as a fire in Luoyang,forging coins by destroying copper wares,relocation of the capital,sharp population decrease,and the destruction of the Ling Observatory. Zhang’s scientific thought and successful practice had played an important role in ideological enlightenments at the primary stage of modern seismology at the end of the nineteenth century. There is a glorious course of"innovation—inheritance—re-innovation"of scientific and technical development from the inception Zhang Heng’s seismoscope to the modern seismograph invented by Milne,et al. 相似文献
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《华北地震科学》2001,(4)
NO.1Q-value structure of the upper crust in Changbaishan Mt.Volcanic region…………Deng Hongzhao,Zhang Xiankang( 1 )……………………………………………………Study on the P and S wave velocity stucture under Tangshan region withdigital earthquake record Zhang xuemin,Shu peiyi et.al.( 1 0 )………………………The application of well-logging with P ang Swave in geotechnical engineering ……Liu Ganghe( 1 8)…………………………………………………………………………The macrointensity of Zhangbei … 相似文献
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“十五”期间即将实施20个省会级城市的活断层探测与地震危险性评价工程。文中对该工程的技术指导性文件“城市活断层探测与地震危险性评价工作大纲(试行)”的基本内容和领会要点进行了阐述。对“工作大纲”的5大属性(科学性、普适性、包容性、可操作性、约束性)作了说明,对探测工程的主要对象活断层和地震活断层进行了界定,对工作区和目标区的内涵及工作途径的差别做了解释。分析了工程所面对的3个层次的科学问题和实施过程中的5个步骤,并对每个步骤中需要注意的事项和应采取的对策分别进行了探讨。文章阐述了探测过程中安排中期验收的必要性,指出本工程是以往各震害防御工作的延续、发展与深入 相似文献
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Liquefaction which is one of the most destructive ground deformations occurs during an earthquake in saturated or partially saturated silty and sandy soils, which may cause serious damages such as settlement and tilting of structures due to shear strength loss of soils. Standard (SPT) and cone (CPT) penetration tests as well as the shear wave velocity (V s)-based methods are commonly used for the determination of liquefaction potential. In this research, it was aimed to compare the SPT and V s-based liquefaction analysis methods by generating different earthquake scenarios. Accordingly, the Erci? residential area, which was mostly affected by the 2011 Van earthquake (M w = 7.1), was chosen as the model site. Erci? (Van, Turkey) and its surroundings settle on an alluvial plain which consists of silty and sandy layers with shallow groundwater level. Moreover, Çald?ran, Erci?–Kocap?nar and Van Fault Zones are the major seismic sources of the region which have a significant potential of producing large magnitude earthquakes. After liquefaction assessments, the liquefaction potential in the western part of the region and in the coastal regions nearby the Lake Van is found to be higher than the other locations. Thus, it can be stated that the soil tightness and groundwater level dominantly control the liquefaction potential. In addition, the lateral spreading and sand boiling spots observed after the 23rd October 2011 Van earthquake overlap the scenario boundaries predicted in this study. Eventually, the use of V s-based liquefaction analysis in collaboration with the SPT results is quite advantageous to assess the rate of liquefaction in a specific area. 相似文献
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Continuous monitoring of soil CO2 dynamic concentration (which is proportional to the CO2 flux through the soil) was carried out at a peripheral site of Mt. Etna during the period November 1997–September 2000 using an automated station. The acquired data were compared with SO2 flux from the summit craters measured two to three times a week during the same period. The high frequency of data acquisition with both methods allowed us to analyze in detail the time variations of both parameters. Anomalous high values of soil CO2 dynamic concentration always preceded periods of increased flux of plume SO2, and these in turn were followed by periods of summit eruptions. The variations were modeled in terms of gas efflux increase due to magma ascent to shallow depth and its consequent depressurization and degassing. This model is supported by data from other geophysical and volcanological parameters. The rates of increase both of soil CO2 dynamic concentration and of plume SO2 flux are interpreted to be positively correlated both to the velocity of magma ascent within the volcano and to lava effusion rate once magma is erupted at the surface. Low rates of the increase were recorded before the nine-month-long 1999 subterminal eruption. Higher rates of increase were observed before the violent summit eruption of September-November 1999, and the highest rates were observed during shorter and very frequent spike-like anomalies that preceded the sequence of short-lived but very violent summit eruptions that started in late January 2000 and continued until late June of the same year. Furthermore, the time interval between the peaks of CO2 and SO2 in a single sequence of gas anomalies is likely to be controlled by magma ascent velocity.Editorial responsibility: H. Shinohara 相似文献
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The algorithm for monitoring the magnetotelluric field has been briefly described, and the experimental data, obtained at
the Bishkek geodynamic site, have been analyzed. The regularities in the seasonal behavior of the variations in the field
vertical magnetic component have been revealed. 相似文献
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A. V. Konovalov A. A. Stepnov D. A. Safonov A. I. Kozhurin A. S. Pavlov A. V. Gavrilov K. A. Manaychev D. Ye. Tomilev H. Takahashi M. Ichiyanagi 《Journal of Seismology》2018,22(4):943-955
An earthquake with the moment magnitude M w ?=?5.8 occurred in the middle part of the Sakhalin Island, Russian Federation, on 14 August 2016, at 11:17 a.m. UTC. The earthquake source was located west of the Central Sakhalin Fault Zone, which is considered to mark the boundary between the Okhotsk and Eurasian (Amurian) plates. Moment tensor solution of the mainshock as well as the configuration of aftershock cloud suggests that the earthquake was caused by slip on a SW-dipping reverse fault. For the first time for Sakhalin, we have got the felt reports unified in accordance with DYFI. We also analyzed observed PGA values and, based on them, produced shaking maps. 相似文献
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一种新的K-Ar和~(40)Ar-~(39)Ar等时线——~(40)Ar/~(40)K-~(36)Ar/~(40)K和~(40)Ar/~(39)Ar-~(36)Ar/~(39)Ar等时线 
下载免费PDF全文
下载免费PDF全文 通过理论推导 ,提出了一种新的K -Ar、4 0 Ar - 39Ar等时线 :4 0 Ar/ 40 K - 36Ar/ 40 K、4 0 Ar/ 39Ar - 36Ar/ 39Ar等时线。通过实例证明它与其它等时线方法可以进行相互检验。在一些不能利用其它等时线方法的情况下 ,新的4 0 Ar/ 40 K - 36Ar/ 40 K和4 0 Ar/ 39Ar- 36Ar/ 39Ar等时线方法可以充分显示它的使用价值和存在意义 相似文献
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太湖霍甫水丝蚓(Limnodrilus hoffmeisteri Claparède)的时空格局 总被引：1，自引：1，他引：0
2005年1-12月对太湖霍甫水丝蚓进行了逐月调查.太湖霍甫水丝蚓年均密度和生物量分别为3273.75 ind./m2和4.697 g/m2,均在2月份达到最大值.根据体长频数分布的周年变化,推测太湖霍甫水丝蚓一年有三代.太湖霍甫水丝蚓密度和生物量在空间上表现出明显的差异性,且随季节变化较小,其高值区域均出现在太湖北部梅梁湾和竺山湾及西部河口湖区,而在其它区域的现存量均较低.分析表明太湖霍甫水丝蚓空间差异可能与营养水平、底质类型、可摄食的食物及生境的稳定性等因素有关. 相似文献