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1.
the Kalpin nappe is an important multiple thrust system. It is important to study the Cenozoic tectonic of the Tianshan Mountain. Holocene active characteristics and paleoearthquake of the Kalpin nappe can be used to evaluate the neotectonic of this area. In this paper, we accurately measured the fault scarp in the front of three thrust-fold faults and analyzed paleoearthquake events in the trenches of the Kalpin nappe. Using the 10Be exposure age, we obtained those geomorphic surface ages and paleoearthquake times. The result showed that the slip rates of the west Kalpintag fault, aozitag fault and the tuoketag fault were 1.45(+1.68/-0.44) mm/a, 0.81(+0.35/-0.19) mm/a and (0.3±0.05) mm/a, respectively since the Holocene. The slip rate indicated that the increased activity transferred from back-row fault to front-row fault and accorded with the piggy-back propagation model in the Tianshan Mountain. Displacements and recurrence intervals of paleoearthquakes was similar to the slip rate characteristics. It also showed paleoearthquakes in the front row fault were stronger than paleoearthquakes of the back row fault. The strong paleoearthquake which caused the highest surface rupture happened in the Kalpintag fault. The interval of paleoearthquakes was about 4 ka and the displacement of every paleoearthquake was about 3 m in the west Kalpintag fault; the interval of paleoearthquakes was about 2 ka and the displacement of every paleoearthquake was about 1m in the aozitag fault; the tuoketag fault ruptured only one paleoearthquake since 7 ka. The Piqiang tear fault was the tectonic result of different shortening rate between the west Kalpin system and the east Kalpin system. The shortening rate of west Kalpin system was obviously stronger than the east Kalpin system. The huge separation distance was near 20 km between the east and the west back-row fault. Because the slip rate of system transferred to the front-row fault in the piggy-back propagation model, the separation distance (~4 km) between the east and the west front-row fault was increasing.  相似文献   
2.
利用宿州地区5个气象观测站1981—2015年的逐日降水资料,将Morlet小波分析方法应用于宿州地区年暴雨发生频次的统计分析,提取其时间序列的振荡周期,考察在不同时段上的变化特征;运用Mann-Kendall (M-K)非参数检验,对宿州地区35 a来的暴雨日及暴雨量进行了时间序列的特征分析和突变检验。结果表明:宿州地区1981—2015年暴雨日具有南多北少的特点,集中发生期为6—8月;近35 a来宿州地区暴雨日和年总暴雨量年际波动虽然较大,但总体呈上升趋势;宿州暴雨发生频次存在多重时间周期尺度上的嵌套复杂结构,存在着5~12 a、3~7 a的短期周期变化规律,1998年以后生成的5 a左右的震荡周期及27 a左右的中期震荡周期;宿州暴雨在2002年发生显著突变,至2008年,增加趋势接近α=0. 05上显著性水平的临界线,2008年以后又缓慢减少。  相似文献   
3.
针对传统统计数据无法准确、客观地测量区域能源消费碳排放量并展现地理分布差异的问题,该文提出利用DMSP/OLS卫星数据稳定夜间灯光数据和能源消费数据,模拟区域碳排放空间分布,揭示区域碳排放分布特征和规律。以河南省为研究区的分析结果表明:1995—2012年河南省能源消费碳排放总量逐年增加,郑州、洛阳和新乡市的能源消费碳排放量年均增长较快,三门峡、济源市的碳排放量增长较慢;2012年各地区能源消费碳排放强度高于1995年,18年间地均碳排放强度均呈现出明显的地域分布差异规律,主要集中在郑州、洛阳和安阳市区域内。基于夜间灯光数据模拟区域能源消费碳排放具有一定的可行性,该数据能比较可靠地反映区域能源消费碳排放的时空动态变化规律。  相似文献   
4.
Dang  Xiaohu  Zhang  Miao  Xia  Zidun  Fan  Liangxin  Liu  Guobin  Zhao  Gaochang  Tao  Rui  Wei  Xuexiao 《GeoJournal》2021,86(4):1639-1655
GeoJournal - As the largest conservation program and payments for ecosystem services in China, the grain-for-green program (GGP) has substantially changed land use and cover, and reduced soil...  相似文献   
5.
利用潮州市气象观测站1969—2011年蒸发量、平均气温、降水、总云量、平均风速、水汽压和相对湿度等资料,采用距平百分率、累积距平、Mann-Kendall、小波分析等方法,分析潮州市蒸发变化特征及其影响因素.结果表明:潮州市蒸发量在20世纪70年代和80年代最多,90年代最少,四季蒸发量的波动比较明显;突变检验表明,20世纪70年代日照时数出现突发性上升,但是没有出现明显突变点;通过对全年和季节蒸发量的周期分析,在比较显著的时间尺度上蒸发量目前处于偏多的时期;年蒸发量减少与平均气温增加关系密切,同时也和夏季日照时数的增加有一定关系.  相似文献   
6.
Multiple earthquakes produced by thrusting deformation have been recorded over the last century in the Tianshan area. Paleoseismic studies are very important in the exploration of the active quaternary tectonics and the risk assessment of great earthquakes in the Tianshan orogenic region. However, in this area, paleoseismic research is still lacking because of the lack of samples dated by 14C or optically stimulated luminescence (OSL) methods. We determined the ages of the alluvial fans by 10Be terrestrial cosmogenic nuclide (TCN) dating, measured the surface deformation of the fault scarp in a GPS survey, and evaluated the vertical displacements of the events in trenches in the east Kalpintage fault in the southwest Tianshan region. We estimated the displacement and recurrence intervals of the paleoseismic events and constrained the errors of the 10Be ages and slip rates using a Monte Carlo simulation method. Our study suggests that each paleoseismic event shows a similar displacement of ~1.5 m with a recurrence interval of ~5 kyr in the east Kalpintage fault. The calculated slip rate is 0.31(+0.21/?0.18) mm/yr. In such arid regions with large areas of coarse gravel that lack 14C or OSL samples, the integration of TCN dating, geomorphic deformation survey, and trenching methods is a reliable alternative for studying the active regional tectonics.  相似文献   
7.
近年来逆冲型破坏性地震频发,这对于逆冲型破裂的古地震研究方法提出了新的要求。由于逆断层角度的变化,在地震中可能表现出截然不同的破裂样式。通过对南天山大量古地震探槽开挖和古地震事件分析研究中发现,低角度逆断层的古地震具有一些常见的破裂类型。本文中挑选了位于南天山三个重要山前逆断裂褶皱带:西段柯坪推覆系、中段库车坳陷的秋里塔格褶皱带和东段焉耆盆地北缘和静逆断裂褶皱带的7个典型探槽剖面,对这类低角度逆断层的古地震进行变形模式、事件识别和位移量计算的总结归纳。低角度逆断层古地震破裂具有以下几种样式并具有各自识别古地震事件和计算位移量的方法:1一条断面对应一次事件的破裂形式,利用断面上断点位置识别古地震事件并判断事件的先后顺序。每个断面各自的位移量正好代表一次事件的位移量。2单条断面多次破裂的样式可以通过上下不同地层的位错量差异判断古地震事件,各个相邻地层之间的位错量差值代表古地震事件的位移量。3多条断面同时破裂的情况表现为多条断面被相同一套地层覆盖,事件位移量为多条断面的位错量之和。4挠曲变形和"推土机"作用是低角度逆断层古地震破裂常见的变形方式,这部分变形量不能忽略,可以通过线平衡和面平衡方法获得断层水平缩短量。  相似文献   
8.
渤张断裂带的构造机制及其地质意义   总被引:10,自引:1,他引:9       下载免费PDF全文
侯贵廷  叶良新 《地质科学》1999,34(3):375-380
渤张断裂带形成于中生代,为剪张性断裂带。中新生代以来渤张断裂带一直活动,并控制中新生代沉积和火山活动。中生代至老第三纪早期(42Ma 之前)渤张断裂带为右旋走滑的剪张性断裂带,而老第三纪中晚期以来(42Ma 以来)渤张断裂带转为左旋走滑的剪张性断裂带,并控制了渤海盆地的油气分布和现代的地震活动。近期,沿渤张断裂带地震活动频繁,说明渤张断裂带仍在活动。  相似文献   
9.
基于潮州市100m×100m的高程数据和包含周边10个气象站点的日照百分率数据,应用GIS技术和回归统计模型对潮州市日照时数的空间分布进行了模拟、结果验证和分析。结果表明,创建的各月和年日照时数空间分布模型显著性水平大多为0.01,研究区内的2个气象站的日照时数模拟值和实际值之间具有很好的一致性,误差百分率在6%以下,模拟结果有实用价值。模拟结果分析发现,潮州市的日照时数除了受太阳高度角影响外,还受天气气候等因素的影响,最低和最高月日照时数分别出现在2月和7月;海拔、坡度等地形因子对日照时数有明显影响,最小日照时数出现在约1100~1200m海拔高度或坡度70°~75°上,低海拔地势平缓地区日照时数明显偏多。  相似文献   
10.
The easternmost Tian Shan lies in eastern Xinjiang, Central Asia. The South Barkol basin fault(SBF) in the northern part of the easternmost Tian Shan is a major tectonic structure in this orogenic region. The late Quaternary activity, paleoseismology, and deformation characteristics of the fault provide important clues for understanding the tectonic process of the eastern Tian Shan orogen and implementing seismic mitigation. Through interpretation of high-resolution satellite images, unmanned aerial vehicle measurements, and detailed geological and geomorphic investigations, we suggest that the fault exhibits clear left-lateral slip along its western segment. Paleoseismic trenches dug near Xiongkuer reveal evidence of six large paleoearthquakes. The four latest paleoearthquakes were dated: the oldest event occurred at 4663 BC–3839 BC. Data on the horizontal offsets along the probable 1842 Barkol earthquake coseismic rupture suggest clear multiple relationships between cumulative offsets and possible ~4 m of coseismic left-lateral slip per event. From the cumulative offsets and 14 C sample ages, we suggest an average Holocene left-lateral slip rate of 2.4–2.8 mm/a on the SBF, accounting for ~80% of lateral deformation within the entire eastern Tian Shan fault system. This result is comparable with the shortening rate of 2–4 mm/a in the whole eastern Tian Shan, indicating an equal role of strike-slip tectonics and compressional tectonics in this orogen, and that the SBF may accommodate substantial lateral tectonic deformation.  相似文献   
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