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Seismogenic Process of the Earthquake Mw6.9 on May 24, 2014 in the Aegean Sea Seismic Cone
爱琴海地震柱2014年6.9级地震的孕震过程
陈立军
博主的一篇英文论文即将发表,题目是“爱琴海地震柱2014年6.9级地震的孕震机理研究”,英文标题为“Study on the Seismogenic Mechanism of theEarthquake Mw6.9 in 2014 in the Aegean Sea Seismic Cone”。本博客为该论文链接的支撑动画材料,欢迎关注,谢谢!
Seismogenic Process Before the Earthquake Mw 6.9 on May 24, 2014 in the Aegean Sea region
The subcrustal earthquake activity in the Aegean Sea area from January 1, 2009 to October 1, 2015 is shown in Blog Figure 1. The figure indicates that seismic activity of volcanic arc block, which was dense seismicat both ends of the volcanic arc, and the red earthquakes under 500 km depth below constituting a super active layer [5] opening to the northwest, was significantly higher than that ofGreek arc block.
The earthquake focal depth sequence of the Aegean Sea from January 1, 2008 to October 1, 2015 is shown in Figure 2. The diagram shows thatafter deep source earthquake activities of Aegean Sea Seismic Cone since 2009 appeared several times of disturbance from bottom to top, fluctuating in the lithosphere, before and after 2010, 2011, 2013 and before 2014 within 220km depth. This was like a stir in the cone body of depth more than 600 kilometers and then caused a series of ripples in the layer close to the ground (lithosphere, within 220km depth), to accumulate energy and find a break through release place finally, which was the weak part of the North Anatolian Fault. During the period there was also 4 earthquakes 6+ in the Greek arc block but failed to release the energy of the volcanic arc block (Blog Figure 1 and Blog Figure 2). In the image, the process is like a tornado, a storm from the deep mantle to the surface of the Earth.
Blog Figure 3 shows all the seismic sets before the earthquake Mw 6.9 fromJanuary 1, 2009 to May 24, 2014. Will this picture is decomposed into 0.1a as aframe of the animation to concentrate the earthquake preparation process of more than 5 years upon ten seconds, the situation is more exciting: after the formation of the earthquake pillar of depth more than 600 km in 2009-2010,there appeared a number of jumps in the layer of 220km depth, until the earthquake occurred(Blog Figure 4, gif).
The time sequence diagram of the epicenter depth of 2005-2015 in the Turkish Branch Seismic Cone is shown in Blog Figure 5, which shows that before the earthquake Mw 6.9 on May 24, 2014 in Aegean Sea, obvious subcrustal seismic activities sign appeared, there was a set of deep seismic activity in 2009-2010 from under ground 656km straight crust, then it beats in less than 220km depth, until an earthquake Mw 6.9 occurred. Will For Figure 5, taking seismic activity in 2008 as background, and then it is made an animation since 2009 and shown a same effect because of no strong earthquakes around 7 in this period in the Aegean sea outside (Blog Figure 6, gif).
A more than 600 km deep seismic activity pillar, stirring within 220km thick stratum, cause the burst of the weak parts of the crust structure and a strong earthquake. The seismogenic process and seismogenic mechanism of the earthquake Mw 6.9 on May 24, 2014 in northern Aegean Sea show that the energy accumulation of a strong earthquake is from deep mantle and it looked for a weak part of the surface structure to break through before the earthquake happened.
Blog Figure1. Premonition Earthquake distribution of the earthquake Mw 6.9 on May 24, 2014 in the northern Aegean Sea
(Jan.1, 2009 –Oct. 1, 2015,M≥1. 5)
Blog Figure2. The seismogenic process of the earthquake Mw 6.9 on May 24, 2014 in the northern Aegean Sea
(Jan.1, 2008 –Oct. 1, 2015,M≥1.7)
Blog Figure 3. A set of earthquake precursors of the earthquake Mw 6.9 on May 24,2014 in the northern Aegean Sea
(Jan.1, 2009 –May 24, 2014, M≥2)
Blog Figure 4 (gif). The precursory earthquake activity in the Aegean sea Seismic Cone before the earthquake Mw 6.9 on May 24, 2014 in the northern Aegean Sea
Blog Figure 5. Seismic focal depth sequence diagram of the Turkish Branch Seismic Cone.
(Jan.1, 2005 –Oct.1, 2015, M≥1.5)
Blog Figure 6 (gif). The precursory earthquake activity in the Turkish Branch Seismic Cone before the earthquake Mw 6.9 on May 24, 2014 in the northern Aegean Sea
中文稿:
2014年5月24日爱琴海6.9级地震前的孕震过程
自2009年1月1日至2015年10月1日爱琴海地区的壳下地震活动如博客图1所示。由图可见,火山弧地块的活动明显高于希腊弧地块的地震活动,壳下地震密集在火山弧的两端,500km深度以下的红色地震构成一个向西北方向开口的能动层。
2008年1月1日至2015年10月1日的爱琴海地震震源深度时序图如博客图2所示。由图可见,自2009年爱琴海地震柱柱体的深源地震活动之后,于2010年、2011年前后、2013年之前和2014年之前在220km深度以内出现若干次的上下扰动(岩石圈内的波动)。这就如同在深达600多千米的柱体内进行了一次搅动,然后在近地表(220km深度以内)引起一连串的涟漪,以便累积能量并寻找释放的突破口,最终选择了北安纳托利亚断裂的薄弱部位。期间内也曾在希腊弧地块中壳下地震较为密集的地区发生过4次6级多一点的强震,但是未能释放掉火山弧地块内的能量(博客图1、博客图2)。倒过图像来看,这个过程就如同一场龙卷风一般,一场来自地幔深部投射到地表的地下风暴。
博客图3为2009年1月1日至2014年5月24日在6.9级地震之前的全部地震集合。将这张图分解为0.1a为一帧的动画,使得5年多的地震孕育过程浓缩到十几秒钟之内,其情形更为精彩:2009-2010年600多千米的深震柱子形成之后,便在220km深度出现多次的波动跳跃,直至强震发生(博客图4,gif)。
土耳其分支地震柱2005-2015年的地震深度随时间的时序图如博客图5所示。由博客图5可见,2014年5月24日的6.9级地震之前出现明显的壳下地震活动征兆,表现为2009-2010年自地下656km直上地表出现一组地震活动,然后则在220km深度以内跳动,直至6.9级地震发生。对于博客图5,取土耳其分支2008年的地震活动为背景,自2009年以后做成动画(博客图6,gif),效果也一样,因为该时段内除爱琴海以外没有7级左右的强震活动。
一个600多千米深的地震活动柱子,激起220km厚的地层内震荡,引起壳内构造的薄弱部位破裂而发生强震。这就是2014年5月24日爱琴海北部海域6.9级地震前的孕震过程和孕震机理,表明强震活动的能量来自地幔深部的能量积累,地震发生时才需要寻找到地表构造的薄弱部位。
博客图1. 2014年5月24日爱琴海北部海域6.9级地震的前兆地震分布(2009.1.1-2014.5.24,M≥1.5)
博客图2. 2014年5月24日爱琴海北部海域6.9级地震的孕震过程(2008.1.1-2014.5.24,M≥1.7)
博客图3. 2014年5月24日爱琴海北部海域6.9级地震的前兆地震集合(2009.1.1-2014.5.24,M≥2.0)
博客图4(gif)2014年5月24日爱琴海北部海域6.9级地震前爱琴海地震柱的前兆地震活动
博客图5. 土耳其分支地震柱的震源深度时序图(2005.1.1-2015.10.1,M≥1.5)
博客图6(gif)2014年5月24日爱琴海北部海域6.9级地震前土耳其分支地震柱的前兆地震活动
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