地震研究

使用区域一维速度模型,利用单纯形法,结合和田台阵的方位角测定了2014年2月12日新疆于田M_S7.3地震的主震位置。使用双差定位方法对于田主震和465次余震序列进行了重新定位。结果表明:NS、EW和UD 3个方向的平均相对误差分别为0.13 km、0.14 km、0.15 km,平均走时残差为0.012 s。余震整体分布呈北东向展布,并向主震的西南和北东两个方向延伸,主震的西南方向长近40 km、宽约30 km,北东方向长近20 km、宽约20 km,震源深度集中在5～15 km。余震序列的空间形态沿破裂显示了分段和非均匀特征:主震的西南方向地震数量较多,展布较宽,且近南北向分布,震源深度优势分布在5～15 km之间; 北东方向地震较少,震源深度优势分布在5～10 km之间; 靠近山脉的地震震源要比远处的深。余震序列的时间特征为在震后的3天内,震源深度集中在5～15 km,此后的震源深度集中在5～10 km,震源深度总体呈现变浅的趋势。

Based on regional 1-D velocity model and combined with the azimuth of Hetian arrays,we determined the epicenter location of Yutian M_S7.3 main shock on Feb. 12,2014 by using the simplex algorithm,and relocated the epicenter location of Yutian M_S7.3 main shock and 465 aftershocks by use of the double-difference location method. The result show that the average relative errors of location accuracy are 0.13 km,0.14 km,0.15 km in NS,EW and UD respectively,and the average travel time residual is 0.012 s. The overall spatial distribution of aftershocks is in NE direction,and extends to southwest and northeast of main shock. The aftershock distribution area in the southwest of main shock are about 40 km long and 30 km wide,those in the northeast are about 20 km long and 20 km wide,and the focal depths focus on 5～15 km. The spatial distribution characteristic of aftershock sequence shows segmental and inhomogeneous along the rupture. The earthquakes in the southwest of the main shock are more,and distribute wide in NS,the focal depths of them mainly distribute in 5～15 km. However,the earthquakes in the northeast of the main shock are less and the focal depth of them mainly distribute in 5～10 km. The focal depth of the aftershock near the mountain is deeper than that of the far. The temporal characteristic of aftershocks sequence are that the focal depth focus on 5～15 km within 3 days after the main shock,thereafter they are 5～10 km,and show the tendency of becoming shallower and shallower.

引言
1 区域地质背景
2 台站及资料选取
3 定位方法 3.1 结合地震台网和地震台阵数据确定震中
4 于田M_S7.3主震重新定位
5 余震序列重定位
6 结论与讨论

图1 2014年2月12日新疆于田MS7.3地震烈度图<br/>Fig.1 Seismic intensity graph of Xinjiang Yutian MS7.3 earthquake on Feb.12,2014

图1 2014年2月12日新疆于田MS7.3地震烈度图
Fig.1 Seismic intensity graph of Xinjiang Yutian MS7.3 earthquake on Feb.12,2014

图2 于田主震、余震震中及其附近地震台站<br/>分布(a)及和田台阵的各子台分布(b)<br/>Fig.2 Distribution of epicenter of Yutian main earthquake and aftershocks,seismic stations in surrounding area(a),and substaions of Hetian array(b)

图2 于田主震、余震震中及其附近地震台站
分布(a)及和田台阵的各子台分布(b)
Fig.2 Distribution of epicenter of Yutian main earthquake and aftershocks,seismic stations in surrounding area(a),and substaions of Hetian array(b)

图3 重定位前(a)、后(b)的于田主震和余震分布<br/>Fig.3 Epicenter distribution of Yutian MS7.3 main shock and aftershocks before(a)and after(b)relocation

图3 重定位前(a)、后(b)的于田主震和余震分布
Fig.3 Epicenter distribution of Yutian MS7.3 main shock and aftershocks before(a)and after(b)relocation

图4 重定位后沿AA'(a)、BB'(b)、CC'(c)、DD'(d)剖面余震深度分布<br/>Fig.4 Focal depth distribution of aftershocks along the profiles of AA'(a),BB'(b),CC'(c)and DD'(d)after relocation

图4 重定位后沿AA'(a)、BB'(b)、CC'(c)、DD'(d)剖面余震深度分布
Fig.4 Focal depth distribution of aftershocks along the profiles of AA'(a),BB'(b),CC'(c)and DD'(d)after relocation

图5 重定位后不同时间段的沿AA'剖面余震深度分布(a)震后24 h;(b)震后25～72 h;(c)震后4～7 d;(d)震后8～15 d
Fig.5 Focal depth distribution of aftershocks in different periods along the AA' profile after relocation (a)within 24 hours after main earthquake;(b)from 25 hours to 72 hours after main earthquake;(c)from 4 days to 7 days after main earthquake;(d)from 8 days to 15 days after main earthquake

表1 2014年2月12日于田MS7.3地震震源参数<br/>Tab.1 The hypocenter parameters of Yutian MS7.3 earthquake on Feb.12,2014

表1 2014年2月12日于田MS7.3地震震源参数
Tab.1 The hypocenter parameters of Yutian MS7.3 earthquake on Feb.12,2014

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备注

引言

1 区域地质背景

2 台站及资料选取

3 定位方法 3.1 结合地震台网和地震台阵数据确定震中

4 于田M_S7.3主震重新定位

5 余震序列重定位

6 结论与讨论

期刊信息

备注

引言