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计算地震学 http://home.ustc.edu.cn/~huaxing1/CompSeis.html 孙道远 [email protected]

计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

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Page 1: 计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

计算地震学http://home.ustc.edu.cn/~huaxing1/CompSeis.html

孙道远

[email protected]

Page 2: 计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

助教

• 贾兴华([email protected], 1014)

• 张 蒙([email protected],703)

Page 3: 计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

课程时间

周一 周二 周三 周四 周五

第一小节

计算地震学

地球动力学

地球物理学进展

第二小节

第三小节 地球内部物理学

地球内部物理学第四小节

第五小节

第六小节

定量地震学

地震勘探进展

第七小节 工程地震学

工程地震学第八小节

第九小节

Page 4: 计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

课程形式

• 讲课(一半)

• 作业展示+文献阅读讲解(一半)

• 参考书:• “Introduction to Seismology”by Peter M. Shearer

• “An Introduction to Seismology, Earthquakes and Earth Structure” by Seth Stein and Michael Wysession

• “Modern Global Seismology” by Thorne Lay and Terry C. Wallace

• “Quantitative Seismology” by Keiiti Aki and Paul G. Richards

Page 5: 计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

课程考核

• 作业(60%)

• 文献阅读讲解(10%)

• 作业展示/课堂测验(5%)

• 期末项目(25%)

Page 6: 计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

期末项目

• Open discussion

• With data

波形模拟

反演走时

震源

……

小组合作

Page 7: 计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

哪个地震的波形图?

答案:Nobody knows. Maybe …

Page 8: 计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

Why can not?

Page 9: 计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

What information are we missing?

Page 10: 计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

What information are we missing?

时间信息

100 秒

t0

Page 11: 计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

What information are we missing?

振幅信息

100 秒

t0

Amp

Page 12: 计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

What information are we missing?

波形信息

100 秒

t0

Amp

Page 13: 计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

To know this earthquake

需要知道:

时间信息 (Travel time)

振幅信息 (Amplitude)

波形信息 (Waveform)

课程目的:

如何计算这些信息。

Page 14: 计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

Global seismology

S(t): Earthquake source

G(t): path effect

R(t): Instrument response

D(t): Recorded data

D(t) = S(t)*G(t)*R(t)

Source Structure

Page 15: 计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

Array data

Seismic dataEarth structure;Seismic sourceInversion (tomography,

Finite Fault inversion …)

Forward

Page 16: 计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

Travel timeData Model prediction

Ray theory: How to calculate travel times of a layered (1D) velocity model?

Page 17: 计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

Earth is not 1D

More than layered model.

Ray tracing in 2D and 3D to calculate travel time.

http://igppweb.ucsd.edu/~gabi/rem2.dir/shear-models.html

Page 18: 计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

Seismic amplitude

• Source (How big is the EQ? Source mechanism?)

• Velocity structure (path effects, Transmission/Reflection coefficients).

• Attenuation effect ( Q ).

D(t) = S(t)*G(t)*R(t)

Page 19: 计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

Waveform is the key

[Carl et al., 2009]

Mo

re a

dva

nce

d m

od

el

Page 20: 计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

Waveform is the key

[Ni et al., 2002]

Need waveform information to sharpcurrent tomography models.

Page 21: 计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

Modeling waveform

• Theoretical (Mode summation, exact solution)

• Semi-analytical based on ray theory (Generalized ray theory, …)

• Numerical method (Propagation matrix, Finite Difference (FD), Spectral Element Method (SEM))

Page 22: 计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

主要内容

1. 波动方程介绍2-3. 走时的计算 (Ray tracing) (HW2-3)

4-5. 振幅的计算 (Transmission/Reflection coefficient, Attenuation,震源机制解) (HW4)

6-7. Semi-analytic解 (Generalized ray,WKM…) (HW5)

8-10. 地球自由振荡 (Model Summation),面波频散曲线11. Receiver function (HW6)

12-15. Numerical解12. Propagation Matrix, Frequency-Wavenumber (FK) (HW7)13-14. Finite Difference (HW8)15. Spectral element method (SEM) (possible HW9)

Page 23: 计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

主要内容

1. 波动方程介绍2-3. 走时的计算 (Ray tracing) (HW2-3)

4-5. 振幅的计算 (Transmission/Reflection coefficient, Attenuation,震源机制解) (HW4)

6-7. Semi-analytic解 (Generalized ray,WKM…) (HW5)

8-10. 地球自由振荡 (Model Summation),面波频散曲线11. Receiver function (HW6)

12-15. Numerical解12. Propagation Matrix, Frequency-Wavenumber (FK) (HW7)13-14. Finite Difference (HW8)15. Spectral element method (SEM) (possible HW9)

RealData

Page 24: 计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

第一次作业

• 到www.iris.edu任意下载一个地震在GSN台网上的所有数据和仪器响应。

• 写一个小程序,读取SAC头文件和数据,可参照SAC自带的readsac.m。

• 按震中距排序,划出Z分量地震波形记录图(自己程序或者pssac),大致标出P波及面波位置。

• 选定一个台站,对三分量去仪器响应。在SAC下去仪器响应和旋转获得R,T分量。

• 针对三分量数据,设别和标注尽可能多的震相。• 确定该台站的最大绝对运动速度。

• http://geophysics.eas.gatech.edu/classes/SAC/• http://www.eas.slu.edu/People/LZhu/home.html for pssac

Page 25: 计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

作业要求

• 目的

• 地图(数据)

• 原理和公式(GMT map)

• 程序设计流程图(源程序)

• 如何证明程序的正确与否?

• 处理过程

• 例子,数据比较

• 结论和讨论

Page 26: 计算地震学 - USTChome.ustc.edu.cn/.../class/Class_Introduction_2017.pdf · 2017-02-14 · • “Introduction to Seismology”byPeter M. Shearer • “An Introduction to Seismology,

• Happy Valentine’s Day!