The Role of Ambient Noise Tomography in Developing

1
The Role of Ambient Noise Tomography in
Developing the California 3-D Seismic Velocity
Model Brief Thoughts

• Past
• application to So. CA.
• group speed maps
• short periods (7 - 18 s).
• Present
• refinement of the method
• application to new regions
• extension to phase velo-
• cIties Love waves
• larger scales, longer periods
• smaller scales, shorter periods
• inversion for 3D Vs.
• Near Future
• joint interpretation with other data.

Central Valley
Oct, 2004
Ventura basin
Imperial Valley
LA basin
Shapiro, Stehly, Campillo, Ritzwoller, High
resolution surface wave tomography from ambient
seismic noise, Science, 307, 615, March 11, 2005.
2
Applications to New Regions (W. US Using TA/
USArray) Inversion for a Crustal Vs
Model
16 sec, group velocity, 10/04-7/06
Map by Morgan Moschetti
3
Applications to New Regions (W. US Using TA/
USArray) Inversion for a Crustal Vs
Model
16 sec, group velocity, 10/04-7/06
4
Applications to New Regions (W. US Using TA/
USArray) Inversion for a Crustal Vs
Model
16 sec, group velocity, 10/04-7/06
Preliminary crustal thickness
Inversion by Morgan Moschetti
5
Extension to Phase Velocities at Longer
Periods High Resolution
Mantle Constraints
25 sec Phase velocity Teleseismic 2-plane
wave method Yang Forsyth
25 sec Phase velocity Ambient noise Yang
Moschetti
6
Closing Comment on the Use of Ambient
Noise Tomography
The Role of Ambient Noise Tomography in
Developing the California 3-D Seismic Velocity
Model Closing Comments

• Complements other kinds of information
• homogeneously distributed
• provides a means to integrate models from
  different regions
• way to extrapolate the model into new areas
• Vs in the crust uppermost mantle
• More useful than traditional surface wave data
• significantly higher resolution
• shorter period, provide constraints on the
  crust.
• Easily introduced into inversions in which other
  data
• are interpreted jointly and with a priori
  constraints.

7
35.5, 242 Tehachapi Mtns
8
37, 242 White Mtns
9
(No Transcript)