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计算河北唐山MS5.1地震过程中潮汐变化,基于该潮汐周期指示背景时间,分析本次地震过程中射出长波辐射（OLR）和遥感大气温度（AT）同步变化。结果显示,2020年7月5日~2020年7月13日,伴随引潮力由低谷向高峰连续增强变化,地震发生在引潮力相对高值时刻;伴随引潮力变化,长波辐射、大气温度经历震前平静-增强-高峰、震后快速衰减的同步变化。表明引潮力在本次地震中改变了构造内部地应力累积-失衡过程,具有触诱发地震的作用,而地面长波辐射、地表大气温度准同步变化,间接反映了本次地震地应力的变化过程。 相似文献
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利用天体引潮力周期变化模型和地面长波辐射(OLR)数据资料,分析2010~2011年云南、西藏地区的4次M5.0以上地震震前OLR异常,探讨了诱发地震的外部因素,即天体引潮力周期与红外异常发展的关联特征。结果显示:以临近发震时刻所在周期引潮力值最低点日期为OLR参照背景,获取的地震前后NOAA长波辐射OLR日增量分布图像显示:震中附近热异常明显,异常受构造控制,且其分布与断裂关系密切;异常演化经历起始-加强-高峰-衰减-再增强-发震-平静的过程,符合岩石因应力增加而破裂的规律。一方面表明地应力的临界状态演化过程可通过OLR辐射变化来反映。另一方面表明引潮力可以改变构造内部地应力的状态。 相似文献
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分析甘肃岷县M_S6.6地震前后潮汐变化发现,发震时刻引潮力处于最低相位点,显示引潮力的诱震属于典型逆冲断层作用类型。以潮汐周期为时间指示,利用NOAA卫星地面长波辐射(OLR)数据,分析震中及其邻近区域(30°~40°N,90°~110°E)地震前后(7月17~25日)地面长波辐射值的连续变化状况,结果显示,震前仅震中及其相关联断裂附近OLR发生了显著且连续的异常变化,在时间上经历了起始增温—异常加强—峰值—衰减—发震—平静的演化过程;在空间上异常区域覆盖震中,与汶川地震引发的应变积累正影响区之南北地震带北段基本吻合;在形态演化上,表现出沿断裂带分散—汇聚—分散的破裂过程,并与岩石应力加载破裂的初始微动破裂—扩张破裂—应力闭锁—地震爆发—恢复平静阶段的力学过程完全吻合。这可能预示该地震发震前后天体引潮力对处于临界状态的活动断层具有诱发作用以及长波辐射异常在一定程度上对地震构造应力应变过程辐射进行表征。 相似文献
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《地震地磁观测与研究》2016,(6)
2014年8月3日中国云南省鲁甸发生M_S6.5地震,震源机制显示为走滑断层,利用NOAA卫星地面长波辐射(OLR)数据资料,对地震前后热辐射值连续变化进行分析,结果显示:在中国大陆范围(20°—45°N,80°—120°E)内,仅震中及相关联断裂附近,地面长波辐射(OLR)在时间上经历了起始增温→异常加强→高峰→衰减→发震→平静的演化过程,在空间上异常沿断裂由北向南向震中迁移。对鲁甸地区引潮力进行计算,结果显示,天体引潮力对本次地震具有显著诱发作用,长波辐射异常可能是地震构造应力应变过程的辐射表征。 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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2013年4月20日在我国四川省芦山（30.284o N, 102.955o E）发生MS7.0地震,计算该地区潮汐变化,地震时刻引潮力处于最低相位点,显示引潮力的诱震作用属于典型逆冲断层作用类型。以此潮汐周期为时间指示（4月12日~4月23日）,利用NOAA卫星地面长波辐射（OLR）数据资料分析全国范围地震前后热辐射值连续变化,结果显示：伴随潮汐演化,在全国范围（17°N-55°N ~ 73°E-155°E）内,震前OLR仅震中及其相关联断裂附近发生了显著而连续异常变化过程：在时间上经历了起始增温→异常加强→高峰→衰减→发震→平静的演化过程;在空间上异常位置与震中基本吻合,发展过程表现出沿断裂带由分散→汇聚→分散的破裂过程,与岩石应力加载破裂演化经历：初始微动破裂→扩张破裂→应力闭锁→地震爆发→平静阶段的力学过程完全吻合,显示天体引潮力对处于临界状态的活动断层具有诱发作用,而长波辐射异常是地震构造应力应变过程辐射表征。将引潮力与OLR异常结合在地震前兆研究中有一定的实用价值。 相似文献
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采用NOAA卫星地面长波辐射（OLR）数据资料,数据空间分辨率为1°×1°、覆盖全球共360×181个格点,时间分辨率为1 d,时间起止为1954年至今。计算了2012年6月30日新疆新源6.6级地震天体引潮力变化和OLR逐日时空演化背景图像。结果表明：①本次地震发生在天体引潮力由高峰（6月20日）→低谷（6月30日）→高峰（7月5日）的周期变化过程由低谷向高峰时段,可能显示引潮力对发震构造的作用主要表现为加速断面的滑动。②+新源6.6级地震前后,亮温区域出现：起始→加强→高峰→衰减→平静→发震→小范围增温的变化过程,即6月25日在震中东北出现小范围的亮温现象,6月26日起亮温区域范围增大,强度增强,6月28日亮温异常范围和幅度减弱,6月29日亮温异常消失。6月30日发生了新源6.6级地震。而7月1日又出现亮温,可能与6月30日的6.6级地震及其后面余震的发生有关。该过程与岩石在受力破裂过程具有相似性,即岩石挤压→岩石微破裂→岩石破裂扩展→破裂终止等。 相似文献
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采用NOAA卫星地面长波辐射（OLR）数据资料,数据空间分辨率为1°×1°、覆盖全球共360×181个格点,时间分辨率为1 d,时间起止为1954年至今。计算了2012年6月30日新疆新源6.6级地震天体引潮力变化和OLR逐日时空演化背景图像。结果表明：①本次地震发生在天体引潮力由高峰（6月20日）→低谷（6月30日）→高峰（7月5日）的周期变化过程由低谷向高峰时段,可能显示引潮力对发震构造的作用主要表现为加速断面的滑动。②+新源6.6级地震前后,亮温区域出现：起始→加强→高峰→衰减→平静→发震→小范围增温的变化过程,即6月25日在震中东北出现小范围的亮温现象,6月26日起亮温区域范围增大,强度增强,6月28日亮温异常范围和幅度减弱,6月29日亮温异常消失。6月30日发生了新源6.6级地震。而7月1日又出现亮温,可能与6月30日的6.6级地震及其后面余震的发生有关。该过程与岩石在受力破裂过程具有相似性,即岩石挤压→岩石微破裂→岩石破裂扩展→破裂终止等。 相似文献
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In this paper, the changes in sediment transport over 51 years from 1955 to 2006 in the Kuye River in the Loess Plateau in China are assessed. Key factors affecting sediment yield and sediment transport, such as precipitation depth, discharge, and human activities are studied. To investigate the changes in sediment yield in this watershed, a trend analysis on sediment concentration, precipitation depth, and discharge is conducted. Precipitation depths at 2 Climate Stations （CSs）, as well as discharge and sediment transport at 3 Gauging Stations （GSs） are used to assess the features of sediment transport in the Kuye River. The rtmoff modulus （defined as the annual average discharge per unit area, L/（s·km^2）） and the sediment transport modulus （defined as the annual suspended sediment transport per unit area, t/（yr km^2）） are introduced in this study to assess the changes in runoff and sediment yield for this watershed. The results show that the highest average monthly discharge during the study period in the Kuye River is 66.23 m^3/s in August with an average monthly sediment concentration of 88.9 kg/m^3. However, the highest average monthly sediment concentration during the study period in the Kuye River is 125.34 kg/m^3 and occurs in July, which has an average discharge of 42.6 m^3/s that is much less than the average monthly discharge in August. It is found that both the runoff modulus and sediment transport modulus at Wenjiachuan GS on the Kuye River has a clear downward trend. During the summer season from July to August, the sediment transport modulus at Wenjiachuan GS is much higher than those at Toudaoguai and Longmen GSs on the Yellow River. The easily erodible loess in the Kuye River watershed and the sparse vegetation are responsible for the extremely high sediment yield from the Kuye River watershed. The analyses of the grain size distribution of suspended load in the Kuye River are presented. The average monthly median grain size of suspended load in the Kuye River is largest in February and then decreases until June. In July, the average monthly median grain size of suspended load approaches another peak and decreases until September. Then, the median grain size of suspended load starts to increase until February of the following year. However, the average monthly median grain size of suspended load in the Yellow River at Toudaoguai and Longmen GSs is the smallest between early summer and late fall The median grain size in the Yellow River starts to increase in November and approaches the largest size in January. 相似文献
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Observations of trace gases (SO2, NH3, NO2 and O3) were made during the period 1981 to 1984 at 6 different locations representative of urban industrial, urban, nonurban, thermal power plant and marine environment. Diurnal variations of the trace gases were studied in an urban environment. Except in the urban industrial environment, the concentration of NH3 was found in the range of background values. Also, the average concentrations of NO2 and O3 at the different environments were in the order of background values. However, the concentrations of SO2 were substantially higher by about 7 times, in urban industrial and thermal power plant environments. The diurnal variations of SO2, NH3 and NO2 showed anitphase relationship with surface temperature at the urban environment station which is relatively free of industrial pollution. Discussion is centred on trace gas variations in different environments in India together with the values reported for various countries in the world. 相似文献
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Ingvar B. Fridleifsson 《Pure and Applied Geophysics》1978,117(1-2):242-252
In an active spreading area like Iceland, where the regional geothermal gradient is in the range 50–150°C/km, it is normally not a problem to find high enough temperature with deep drilling, but the difficulties arise with finding permeable layers at depth within the strata. Various volcanological methods can be applied in the search for aquifers and geothermal reservoir rocks. The flow pattern (as deduced from deuterium studies) indicates that the thermal water flows preferentially along high porosity stratiform horizons and dyke swarms from the recharge areas in the highlands to the hot spring areas in the lowlands. The primary porosity of the volcanic strata is dependent on the chemical composition and the mode of eruption of the volcanic units. Both the reservoir rocks and the flow channels forming the geothermal plumbing system are thought to vary from the Tertiary to the Quaternary provinces due to environmental conditions at the eruptive sites. 相似文献
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3He/4He ratios up to 3.5 times the ratio of atmospheric He were found in groundwater samples. The3He enrichment can be attributed to radiogenic3He produced by in-situ beta-decay of3H. This shows that tritiogenic3He is accumulating in confined waters. From tritiogenic3He and3H concentrations, ages of groundwaters can be calculated. Detection of tritiogenic3He gives a tool to trace a tritium contamination which occurred in the past and cannot be assessed only by the3H counting method. 相似文献
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The aim of this study is to estimate likely changes in flood indices under a future climate and to assess the uncertainty in these estimates for selected catchments in Poland. Precipitation and temperature time series from climate simulations from the EURO-CORDEX initiative for the periods 1971–2000, 2021–2050 and 2071–2100 following the RCP4.5 and RCP8.5 emission scenarios have been used to produce hydrological simulations based on the HBV hydrological model. As the climate model outputs for Poland are highly biased, post processing in the form of bias correction was first performed so that the climate time series could be applied in hydrological simulations at a catchment-scale. The results indicate that bias correction significantly improves flow simulations and estimated flood indices based on comparisons with simulations from observed climate data for the control period. The estimated changes in the mean annual flood and in flood quantiles under a future climate indicate a large spread in the estimates both within and between the catchments. An ANOVA analysis was used to assess the relative contributions of the 2 emission scenarios, the 7 climate models and the 4 bias correction methods to the total spread in the projected changes in extreme river flow indices for each catchment. The analysis indicates that the differences between climate models generally make the largest contribution to the spread in the ensemble of the three factors considered. The results for bias corrected data show small differences between the four bias correction methods considered, and, in contrast with the results for uncorrected simulations, project increases in flood indices for most catchments under a future climate. 相似文献
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This paper briefly summarizes the works in the processing of strong ground motion data, the factors affecting strong ground motion, the modeling of strong ground motion and the calculating of broad-band response spectrum which have been done recent years by engineering seismologists and seismologists of China. In addition, we think back to the international cooperation in strong ground motion of the recent years and make some expectations for the future. 相似文献