跨断层短水准观测异常与地震活动关系的研究

发布时间：2018-03-21 00:39

本文选题：跨断层　切入点：短水准流动观测　出处：《西安科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：地球,一直经历着多种自然灾害的影响。在众多自然灾害中,地震是给人类社会带来巨大灾难的一种自然现象。特别是在造成经济损失、人员伤亡以及工程建设等方面具有巨大的破坏性,以及给人口稠密、工业发达的地区造成的损伤的严重性,堪称众多自然灾害之首。因此,地震预测预报早已引起世界各国的高度重视,也是一项既迫于回答、又需要长期的探索总结才能解决的世界性科学难题。通过研究地震前兆异常信息,作为地震预测预报的依据具有重要的意义,同时对工程建设、防震减灾事业有重大意义。本文则是对西秦岭、青藏高原东北缘的兰州—天水—武都监测区域的短水准观测数据进行处理,分析讨论震前断层形变异常特征及与地震活动的关系。通过对已有数据资料的认真、严谨的计算,全面、深入的分析研究及系统性的梳理,结合该研究区域的已有GPS水平运动形变、区域水准垂直运动形变及重力异常的研究结果为背景,以甘肃岷县6.6级地震为实例分析。主要取得以下初步性研究成果和认识:(1)短水准观测反映的震前断层活动存在明显异常,异常形态主要有趋势型和突变型两大类;异常持续时间与震中距、震级在局部上存在一定的比例关系;异常幅度与震中距在局部上存在着正比关系;(2)短水准观测反映的断层形变异常幅度偏离动态基值线超出2倍拟合中误差后一段时间内极有可能发生地震。(3)岷县6.6级地震可能发生在青藏块体水平运动受阻,区域垂直运动和重力变化高梯度带背景下,同时震区跨断层短水准观测反映的断层形变异常偏离动态基值线幅度2倍拟合中误差的尖点突跳和“W”型波动后;且本次地震前断层形变异常表现为震中距为50~100km形变异常显著,且幅度较大;异常形态呈短-临期“V”型突跳和“W/M”型波动,异常持续时间多以短期4~12个月为主。
[Abstract]:The earth has been experiencing various natural disasters. Many natural disasters, the earthquake is a natural phenomenon that has brought great disaster to human society. Especially in the economic losses caused by devastating casualties and construction, as well as for population density, resulting in serious developed industrial areas the injury, as many natural disasters. Therefore, earthquake prediction has attracted great attention in the world, is also a forced answer, and the need for long-term exploration of the world of science. In order to solve the problem through the study of seismic anomaly information, it is important to predict the earthquake forecast as the basis, at the same time on the construction, is of great significance to earthquake prevention and disaster reduction. This paper is on the west of Qinling Mountains, short leveling the northeastern margin of the Qinghai Tibet Plateau in Lanzhou Tianshui Wudu area monitoring Data processing, analysis and discussion of fault deformation anomaly before the earthquake characteristics and relationship with seismic activities. Based on the existing data of the serious, rigorous calculation, comprehensive research and systematic analysis and in-depth analysis, combined with the existing deformation of GPS horizontal movement in the study area of research, regional level vertical movement deformation and gravity anomaly the background, in Gansu Minxian 6.6 earthquake as an example analysis. The following preliminary research results and understanding: (1) there are obvious abnormal fault activities reflect the leveling data before the earthquake, abnormal shape to the trend and mutant two categories; the duration time and epicentral distance, there are certain magnitude the ratio between the local anomaly magnitude and epicentral distance; a proportional relationship exists in the local; (2) the fault deformation anomaly amplitude reflects the leveling data from more than 2 times the dynamic base value line fitting A period of time after the error is very likely the earthquake. (3) Minxian 6.6 earthquake occurred in the Qinghai Tibet block may be blocked horizontal movement, vertical movement and regional high gradient zone of gravity variation under the background of cusp earthquake fault deformation process also reflects the cross fault leveling data base line dynamic deviation amplitude error 2 in the times of fitting jump and "W" type wave after the earthquake; and the performance of fault deformation anomaly before the epicentral distance for 50~100km deformation was significantly abnormal, and the amplitude is large; the anomalies were short - the advent of "V" and "W/M" type of jump volatility anomaly duration in short-term 4~12 months..

【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P315.7

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