DESCRIPTION
觀測地震學 實習 Exercise of Observation Seismology 1. 識別 P- 和 S- 波 1. Determine P and S wave 2. 地震定位 2. earthquake locating. 蒲新杰 [email protected]. 實習 Exercise. Laboratory : S319. Platform : Linux. User/password : GP6049/student62057 Picking : SAC (Seismic Analysis Code). - PowerPoint PPT PresentationTRANSCRIPT
觀測地震學實習Exercise of Observation Seismology 1. 識別 P- 和 S- 波 1. Determine P and S wave
2. 地震定位 2. earthquake locating
實習 Exercise
• Laboratory : S319.• Platform : Linux.• User/password : GP6049/student62057• Picking : SAC (Seismic Analysis Code).• Location : Hypo 71.• Time : ??
地震定位 - 震波訊號Earthquake Locating –Seismic
Record•測站的資訊( 地震波訊號 ) Seismic record of each station 定位程式 + 速度模型location program+ velocity structure 震源參數( 位置規模 )Parameter of hypocenter (location & magnitude)•單站資料 single station
•多站資料 multiple stations
Introduction to SeismologyPeter M. Shearer, 1999
Surface
3-component seismograms
I/E0-4U/DP
I/E0-4SpaceS F
PPK
• N: next plot• B: previous plot• X: Zoom in• O: previous plot window (Zoom out)• H: Write picks to HYPO pick file.
定位程式 Earthquake Locating Program
• 1. IRIS• Platform : Windows.• Method : Trial and error.• H.W.: Seismic waveform (CWBSN).• Note : 取 Z 方向資料 , 最多 10筆資料 . Take data of Z component, no more than ten. 課程流水號 (解壓縮密碼 ) ： 62060 Course Number (unzip password) :62060• 2. Hypo71• Platform : Unix & Windows.• Method : Inversion.• H.W.: Seismic waveform (CWBSN).
Hypo 71
iii tTR
極小化 (minimize) ei
iiii
i edzztdy
ytdx
xtdtR
Geiger’s method, 1912
• input ： 1. P-and/or S-waves 到時 arrival time. 2. 速度模型和測站坐標 . velocity structure and coordinates of earthquake stations.
• output：發震時間、震源位置、規模、時間殘差、震源誤差、定位品質等。hypocenter time, hypocenter location, magnitude, Residual
time RMS, standard error of the epicenter in km at Horizontal and Vertical , Quality, ….
速度模型和測站坐標velocity structure and coordinate of earthquake station
計算地震規模 (MD) ，其經驗公式為：Calculated duration magnitude(MD):
MD = -0.87 + 2.0 log + 0.0035
式中為總振動時間（以秒為單位），為測震站到震央的距離（以公里為單位）。Which : total shaking duration (sec.), :distance from station to epicenter (km)
Output-file decode
DATE
ORIGIN
LAT-N
LONG-
E
DEPTH
MAG
NO
GAP
DMIN
RMS
ERH
ERZ
QM
2001/12/01
00/39/23.63
22-25.66
120-31.44
24.78 2.12 35 261 9.8 0.26 1.8 1.1 C1
QS RMS ( sec ) ERH ( km ) ERZ ( km )
A LT. 0.15 LE. 1.0 LE. 2.0
B LT. 0.30 LE. 2.5 LE. 5.0
C LT. 0.50 LE. 5.0
D Others
QD NO ( P+S ) GAP DMIN
A GE. 6 LE. 90 LE. Depth or 5 km
B GE. 6 LE. 135 LE. 2*Depth or 10 km
C GE. 6 LE. 180 LE. 50 km
D Others
Q Epicenter Focal Depth
A Excellent Good
B Good Fair
C Fair Poor
D Poor Poor
觀測波形Observation waveform
挑選初達 P 和 S 波Picking first arrival P and S
Hypo71
決定震源位置及發震時間Calculated hypocenter location and
time
流程圖 Flowchart
速度模型、測站坐標及參數設定Velocity structure, Station location
and Parameters