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中国天山北坡西部精河流域山区的树木年轮记录了气候与水文变化过程,利用树轮宽度重建流域径流量长期变化历史对艾比湖湿地自然保护区生态保护和流域水资源利用具有重要意义.建立了精河流域山区2个采样点的天山云杉树轮宽度年表,分析其对流域气象和水文要素的响应特征,建立了树轮宽度标准年表与精河水文站上年9月到当年8月径流量的线性转换方程(R2=37.5%, P<0.001),重建了公元1615—2007年的径流量变化历史.丰枯年份和持续丰枯期分析表明:精河出山口径流量重建序列包含7个丰水年和11个枯水年,且发生了13次持续丰水期和10次持续枯水期.多窗谱分析发现径流量序列在99%的置信水平上存在56.8 年、6.9 年、3.8 年、3.4 年、2.0~2.1 年周期,其中6.9 年对应厄尔尼诺-南方涛动(ENSO)事件的周期,同时还发现了重建序列与南方涛动指数的显著负相关(r =-0.329,n=56),表明研究区径流量受大尺度海气耦合模式的影响.精河径流量序列与天山北坡玛纳斯河和乌鲁木齐河的丰枯阶段以及天山山区、伊犁地区降水变化的干湿阶段较好的对应,表明天山北坡水文和气候变化的大尺度环流背景和驱动因子一致. 相似文献
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THE FLUID GEOCHEMICAL VARIATION CHARACTERISTICS OF THE WUSU MUD VOLCANOES BEFORE THE JINGHE EARTHQUAKE OF MS6.6 ON AUGUST 9, 2017
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ZHU Cheng-ying ZHOU Xiao-cheng MA Rong YAN Wei LIANG Hui ZHANG Tao GAO Xiao-qi YAN Yu-cong 《地震地质》2019,41(4):1060-1075
Mud volcano is a conical sedimentary body formed by high-pressure mud and gas-dominated fluid migrated to the surface through faults and other channels deep underground, which looks like a volcanic cone formed by magma-volcanism. As a product of crustal movement, mud volcano can bring a large amount of valuable information from deep to the surface when erupting. Therefore, mud volcano is called "god-given borehole" with a depth of 7~12km. Mud volcanoes are the result of upthrust of trapped gases released by the pressure in the stratum and also the channel for the upward migration of gases in the earth. The submarine mud volcano is one of the signs of hydrate and the living evidence of hydrate. The Wusu mud volcanoes are located in the northern Tianshan tectonic belt. Since the mud volcamoes locate in the active part of the tectonic belt and are well connected to the underground, their active degree has a good correlation with the seismicity. The earthquake cases studies based on the 7a long real-time macroscopic monitoring data and the more than 3a long geochemical monitoring data of the Wusu mud volcanoes show that in the earthquake cases of MS ≥ 5.0 within the range of 300km around the Wusu mud volcanoes, the abnormal mud gushing quantity obviously increased by macroscopic monitoring before 9 out of 13 earthquakes. The geochemical microcosmic monitoring data showed obvious abnormal changes before 3 out of 6 earthquakes. The anomalous duration from the emergence of the anomaly to the occurrence of the earthquake is mainly of the mid-term(6~12 months). Before the Jinghe MS6.6 earthquake on August 9, 2017, the Wusu mud volcanoes spewed violently and the chemical components showed an obvious high value anomaly. In January 2017, there was a significant increase in the amount of mud spewing in Aiqigou No.1mud volcano and Baiyanggou No.1mud volcano, and one month before the earthquake, there was the phenomenon that mud gushing amount of Aiqigou No.2 mud volcano gradually increased and the volcano was from dormant to active. There were obvious high values appearing before the earthquake in F-and SO42- in the Aiqigou No.1mud volcano and in F-, CO32-, SO42-, Rn(gas), CH4, Ar and N2 in Baiyanggou(No.1 and 2)mud volcanoes. The values of F-, CO32-, SO42-, Ar and N2 showed short-term anomalies, while CH4 and Rn(gas)showed medium term anomalies. Giggenbach triangular diagram (Na-K-Mg) indicates that the water-rock reaction of Baiyanggou mud volcanoes is complete and little disturbed by the outside. The water-rock reaction of the Aiqigou mud volcanoes is still ongoing, which can explain why the precursor anomaly of the chemical components of the Baiyanggou mud volcanoes is more obvious than that of the Aiqigou mud volcanoes. The geothermal reservoir temperature of the study area is estimated by using a cationic (Na-K, K-Mg, Na-K-Ca) geothermometer. The geothermal reservoir temperature of the Wusu mud volcanoes is about 70℃, and the circulation depth is about 3km. In the process of earthquake preparation, the mud carries deep chemical components to the ground surface due to the effect of compression stress(the result of focal mechanism)or the concentration of regional tectonic stress with earthquake preparation; Or the rock strata in or near the seismogenic area are deformed, the depth of liquid circulation will increase, and the water-rock reaction will be accelerated, which will increase the concentration of some ionic components, and the squeezing process will cause a large number of mud to gush out of the ground, carrying geochemical components. Therefore, the gushing quantity and some chemical components of the mud volcanoes were obviously abnormal before the earthquake. 相似文献
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在中国地震台网中心2016年底利用热红外遥感技术预测2017年新疆西部地区为潜在MS 6.6±0.2地震危险区的基础上,分析2017年8月9日精河MS6.6地震临震时段引潮力变化,并选用18时(UTC)中国大陆近地表50m高度处的遥感大气温度数据,以震前引潮力值最高点时刻(8月1日)为时间背景,获取地震前后(8月2~13日)连续的大气温度日增量分布图像,跟踪分析精河MS6.6地震短临大气温度变化。结果显示:地震发生在天体引潮力由高峰—低谷连续周期变化的低谷时段,而大气温度变化过程显示,在全国大范围内,仅震中附近大气温度升高明显,其异常演化经历了起始—加强—高峰—衰减—再增强—发震—平静的动态过程。增温过程与潮汐变化具有同步性,这表明引潮力对本次地震具有触诱发的作用,而大气温度变化反映了本次地震地应力的变化过程,也说明在地震预测实践中,从中、短临多时间尺度综合分析遥感大气温度和引潮力变化,将有助于提高地震预测能力。 相似文献
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基于震源机制解的断层三维动画自动生成系统以地震应急实际需求为导向,根据震源机制解提供的断层走向、倾角和滑动角,通过对断层模型进行三维建模,建立断层控制点的运动方程,利用动画自动生成技术,生成发震断层的三维演示动画。利用该系统制作了九寨沟7.0级、精河6.6级地震的三维运动动画。该系统自动产出的断层三维动画,可在地震应急期间为抗震救灾指挥部展示直观的断层运动过程,并且结合余震分布等信息可为震后趋势的判定提供科学依据,同时,可借助微博、微信等新媒体为社会公众提供更好的服务。 相似文献
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利用相对功率谱方法对风云卫星热红外亮温数据进行处理,发现精河MS6.6地震前存在明显的前兆异常。异常时空演化特征为2017年7月12日在北天山地震带中、东部和阿尔泰地震带中部开始出现相对功率谱高值聚集现象,随后幅值和面积逐渐增大,持续至7月27日异常面积和幅度达到最大值,然后逐渐减弱,2017年8月14日后基本恢复正常,异常持续大约1个月,8月9日在异常区域边缘发生精河MS6.6地震。地震震中所在的北天山地震带平均相对功率谱值时序变化特征与异常区域时间演化过程类似,地震发生在平均相对功率谱由最大值恢复至正常背景值的过程中。 相似文献
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新疆艾比湖主要入湖河流精河与博尔塔拉河三维荧光光谱特性及其与水质的关系 总被引:4,自引:4,他引:0
以艾比湖主要入湖河流——精河与博尔塔拉河为研究对象,分别分析了精河与博尔塔拉河的水体溶解性有机质(DOM)的组成结构及水质参数与荧光指数的关系.利用平行因子分析法对三维荧光光谱(EEM)分析发现,精河与博尔塔拉河均含有C1(260/420 nm)腐殖酸等有机质、C2(240,240/490 nm)UVC类腐殖质、C3(220/280,300/450 nm)蛋白质类有机质和C4(260,270/530 nm)类腐殖质,且不同荧光组分结构具有一定差异性.为了进一步了解DOM组分特征,采用三维荧光区域积分法分析各区域标准体积百分比,结果表明精河与博尔塔拉河EEM的区域Ⅰ与区域Ⅱ蛋白质有机质含量最高,区域Ⅲ富里酸含量最低.相关性分析表明,主要入湖河流的水质参数与荧光指数中,自生源指数(BIX)与总氮(TN)浓度以及腐殖化指数(HIX)与铵态氮(NH_4~+-N)浓度的相关性较强,相关系数分别为0.831和0.684,且具有显著性;HIX与TN浓度的相关系数为0.604,达到显著性水平.进而对相关性较强的水质参数与荧光指数进行3次拟合,其中HIX与NH_4~+-N浓度的拟合效果最好,相关性系数为0.908,其次是BIX与TN浓度,相关性系数为0.844.总之,通过分析精河与博尔塔拉河三维荧光特征,以及探讨荧光指数与水质参数的关系,可为治理干旱区水环境问题提供理论依据和参考. 相似文献
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利用Sentinel-1降轨卫星数据,研究2017-08-09新疆精河MW6.3地震的同震形变与断层滑动破裂。考虑轨道和大气误差的影响,基于模型改正后的精细同震干涉图显示,视线向最大地表位移约为7 cm,未发现有地表破裂。此外,基于弹性半空间位错模型,采用两步法策略分别反演地震的均匀断层几何参数和同震滑动分布,结果显示,精河地震发震断层以逆冲运动为主,主破裂区位于8~17 km深度,最大滑移量为0.6 m,表明该地震是一次由逆冲型隐伏断层产生的单次破裂事件。InSAR结果给出的地震释放矩能量为2.91×1018 Nm,相当于矩震级MW6.25,与USGS、CENC等机构给出的震级一致。 相似文献