Earthquake Data Integration

1
Earthquake Data Integration

• GOCAD Instructions

2
Earthquake Data Integration

• Earthquakes and Structural Geology
• Beach balls and other plots
• Using GOCAD

3
Earthquakes and Structure
Type of fault, orientation of fault plane
Location of faults
4
Beach balls and other plots
5
Beach balls and other plots
Dilational first arrival
map
Compressional first arrival
6
Beach balls and other plots
7
Using GOCAD

• For integration with other data (topography,
  geologic sections, fault models, bore holes )
• For 3d visualization
• see demo

8
Using GOCAD
Tutorial user information use SSH to login to
rupture user tutorial pw ask George rupture
01 cd beachballs/epslabX u\beachballs\epslabX\
9
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 4.93 33-30.23 116-46.57 0.95
  1.40 19 0 19.0 0.09 0.2 1.6 c 255 80 160
  0.00 12 0.08 0.74 0.00 15 33 20C 0
• Date Time Sec. Latitude Longitude Dept
  Mag A1 A2 A3 A4 h_e v_e M ddi dp rak
  A5 A6 A7 A8 A9 A10 A11 A12 EventID
• uses dip direction of nodal plane

10
Using GOCAD
Importing GMT style data into GOCAD rupture 85
cd gmt

• Convert geographic coordinates to UTM
  coordinatesrupture 93 proj -r projutm
  zone11 smb81_98.geo gt smb81_98.utm
• Convert UTM file to GOCAD filerupture 105
  /sger/tools/beachball.awk smb81_98.utm gt
  smb81_98.gpbeachball.awk expects STRIKE

11
Using GOCAD
More beach ball options rupture 85 cd gmt

• Produce larger beach ballsrupture 105
  /sger/tools/beachball.awk RADIUS1000
  smb81_98.utm gt smb81_98.gp
• The variable RADIUS defines the radius of a
  magnitude 1 focal sphere (default 200).
• Produce nodal planes and P-T axesrupture 105
  /sger/tools/nodals.awk smb81_98.utm gt
  smb81_98.nodYou can use the variable RADIUS
  with nodals.awk as well.nodals.awk expects
  STRIKE.

12
Using GOCAD
Importing FPFIT style data into GOCAD rupture
85 cd fpfit

• Convert FPFIT file to GMT style filerupture
  118 /sger/tools/fpfit2geo.awk smb81_98.fps gt
  smb81_98.geo
• Convert geographic coordinates to UTM
  coordinates
• Convert UTM file to GOCAD filerupture 105
  /sger/tools/beachball_ddir.awk smb81_98.utm gt
  smb81_98.gp
• beachball_ddir.awk/nodals_ddir.awk expect DIP
  DIRECTION

13
Using GOCAD

• Beach ball summary
• beachball.awk usagebeachball.awk
  RADIUSmeter gmtfile gt gocadfilegmtfile
  format any number of lines containingXm Ym
  Zkm 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

14
Using GOCAD
Importing large EQ data sets in GOCAD rupture
85 cd mining

• Convert FPFIT file to GMT style filerupture
  118 /sger/tools/fpfit2geo.awk smb81_98.fps gt
  smb81_98.geo
• Convert geographic coordinates to UTM
  coordinates
• Convert UTM file to GOCAD point set
  filerupture 144 /sger/tools/eq2vs.awk
  smb81_98.utm gt smb81_98.vs

15
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
16
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 ..
17
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