Transcript presentation source

Earthquake Data Integration
GOCAD Instructions
2
Earthquake Data Integration
• Earthquakes and Structural Geology
• Beach balls and other plots
• Using GOCAD
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Earthquakes and Structure
Location of faults
Type of fault,
orientation of fault plane
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Beach balls and other plots
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Beach balls and other plots
Dilational first arrival
Compressional
first arrival
map
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Beach balls and other plots
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Using GOCAD
• For integration with other data (topography,
geologic sections, fault models, bore holes
…)
• For 3d visualization
• see demo
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Using GOCAD
Tutorial user information:
use SSH to login to rupture
user: tutorial
pw : ask George
rupture 01% cd beachballs/epslabX
u:\beachballs\epslabX\*
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Using GOCAD
Typical raw data of focal mechanisms
• Input for psmeca module of GMT plotting software:
33.75 -118.13 -10.86 220.00 75.00 -70.00 2.40 000 000 43732
Lat. Long.
Depth strike dip
rake
Mag. Xmp Ymp Name
uses strike of nodal plane
• Output of FPFIT program:
810223 1921
Date
Time
4.93 33-30.23 116-46.57
Sec. Latitude Longitude
0.95
Dept
1.40 19
Mag A1
0 19.0 0.09
A2 A3
A4
uses dip direction of nodal plane
0.2
h_e
1.6
v_e
c 255 80 160
M ddi dp rak
0.00
A5
12
A6
0.08 0.74 0.00 15 33 20C*
A7
A8
A9
A10 A11 A12
0
EventID
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Using GOCAD
Importing GMT style data into GOCAD:
rupture 85% cd gmt
• Convert geographic coordinates to UTM coordinates:
rupture 93% proj -r +proj=utm +zone=11 smb81_98.geo > smb81_98.utm
• Convert UTM file to GOCAD file:
rupture 105% /sger/tools/beachball.awk smb81_98.utm > smb81_98.gp
beachball.awk expects STRIKE
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Using GOCAD
More beach ball options:
rupture 85% cd gmt
• Produce larger beach balls:
rupture 105% /sger/tools/beachball.awk RADIUS=1000 smb81_98.utm > smb81_98.gp
The variable RADIUS defines the radius of a magnitude 1 focal sphere (default = 200).
• Produce nodal planes and P-T axes:
rupture 105% /sger/tools/nodals.awk smb81_98.utm > smb81_98.nod
You can use the variable RADIUS with nodals.awk as well.
nodals.awk expects STRIKE.
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Using GOCAD
Importing FPFIT style data into GOCAD:
rupture 85% cd fpfit
• Convert FPFIT file to GMT style file:
rupture 118% /sger/tools/fpfit2geo.awk smb81_98.fps > smb81_98.geo
• Convert geographic coordinates to UTM coordinates
• Convert UTM file to GOCAD file:
rupture 105% /sger/tools/beachball_ddir.awk smb81_98.utm > smb81_98.gp
beachball_ddir.awk/nodals_ddir.awk expect DIP DIRECTION
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Using GOCAD
Beach ball summary:
• beachball.awk usage:
beachball.awk [RADIUS=meter] gmtfile > gocadfile
gmtfile format: any number of lines containing
X[m] Y[m] Z[km] strike dip rake magnitude 0 0 Name
• beachball expects strike, beachball_ddir dip direction
• nodals[_ddir].awk produces nodal planes/P-T axes, same usage
• use proj to convert geographic coordinates into utm
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Using GOCAD
Importing large EQ data sets in GOCAD:
rupture 85% cd mining
• Convert FPFIT file to GMT style file:
rupture 118% /sger/tools/fpfit2geo.awk smb81_98.fps > smb81_98.geo
• Convert geographic coordinates to UTM coordinates
• Convert UTM file to GOCAD point set file:
rupture 144% /sger/tools/eq2vs.awk smb81_98.utm > smb81_98.vs
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Using GOCAD
Filtering large EQ data sets in GOCAD:
change property used for colors
Choose color map or make one (Edit)
Custom color map for rake
right-lateral
normal sense
left-lateral
thrust sense
right-lateral
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Using GOCAD
Filtering large EQ data sets in GOCAD (example):
change to date
choose color map rainbow1
edit Low and High clip values
make transparent to display
only earthquakes in 1982
Use property regions to separate
earthquakes by date, magnitude ..
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Using GOCAD
Filter with a GOCAD script and export to GMT style file:
Type in script
Or load file:
gocadfilter.script
Convert smb81_98_mag3
to beach balls