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SURFACE WAVE TOMOGRAPHY
OF EURASIA
Address questions
and/or comments to ritzwoller@phys-geophys.colorado.edu
Supported by:
- AFTAC Contract F19628-95-C-0099
- AFOSR Contract F49620-95-1-0139
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Scientists: Mike Ritzwoller,
Anatoli Levshin.
Analysts: Luda Ratnikova,
Steve Smith,
Dave Tremblay, Mike Silitch, Chris Lee.
We are performing a systematic
study of surface wave dispersion across Eurasia. The study is currently
performed on two scales: on a continent-wide scale with group velocity
maps constructed on a 1x1degree grid across the entire continent, and on
a regional scale with the construction of a vs model across Central Asia.
We include below links to graphical images of the group velocity maps on
both scales. In Central Asia we only present group velocity maps from 10
- 50 s period since at longer periods smaller scale features become less
prominent. In each case, images are presented in both gif and postscript
format (for downloading), and the ascii data files are also available for
down loading.
These maps and models are
continually being updated, and the images and data files included here
are not necessarily the most up to date. To check on the status and availability
of the latest maps and models, contact Mike Ritzwoller at the email address
listed above.
Eurasia (Continental
Scale)
Earthquakes
and Stations (12/7/96)
Group
velocity - frequency analysis
Description
of cluster analysis
GMT
example for plotting data files across Eurasia (4 files)
Tomography
and Inversion
All
measured group velocity curves
Some
of the waveform data (1988-1992) are available in the `Eurasian Tomography
Information Product'
Directions
for future research (9/96)
Central Asia(Regional
Scale)
Earthquakes
and Stations (12/7/96)
GMT
example for plotting data files across Central Asia (4 files)
Directions
for future research (9/96)
vs Model
Description of inversion:
page 1, page
2, page 3
Several
depth profiles across Tibet
Sedimentary
thickness compared with CRUST-5.0 (note: old
(4/95) preliminary version of the CRUST model series)
Depth
to Moho (from geoid) compared with surface topography
Mantle
(80 - 220 km, 220 - 400 km)
Mantle
(80 - 220 km) across all of Eurasia compared with S16/B30
Discussion
concerning Tibet
Download the model and
auxiliary information: README,
vs_model (3.83 Mb)
Our maps and profiles of sediment
thickness and Moho depth can be viewed and compared with others using Cornell's
Middle East and N. Africa Project Information and Data Server:
References
Related Publications:
- Levshin, A.L., M.H. Ritzwoller, and L. I. Ratnikova,
The nature and cause of polarization anomalies of surface waves crossing
northern and central Eurasia, Geophys. J. Internatl., 117, 577 - 590, 1994.
- Ritzwoller, M.H., A.L. Levshin, S.S. Smith, and C.S.
Lee, Making accurate continental broadband surface wave measurements, Proceedings
of the 17th Seismic Research Symposium on Monitoring a CTBT, 482-490, 1995.
- Levshin, A.L. and M.H. Ritzwoller, Surface wave group
velocity measurements across Eurasia, Proceedings of the 17th Seismic Research
Symposium on Monitoring a CTBT, 226-236, 1995.
- Levshin, A.L. and M. H. Ritzwoller, Characteristics
of surface waves generated by events on and near the Chinese nuclear test
site, Geophys. J. Int., 123, 131-149, 1995.
- Ritzwoller, M.H., A.L. Levshin, L.I. Ratnikova, and
D.M. Tremblay, High resolution group velocity variations across Central
Asia, Proceedings of the 18th Seismic Research Symposium on Monitoring
a CTBT, 98 - 107, 1996.
- Levshin, A.L., M.H. Ritzwoller, and S.S. Smith, Group
velocity variations across Eurasia, Proceedings of the 18th Seismic Research
Symposium on Monitoring a CTBT, 70 - 79, 1996.
Related
Abstracts
If you have questions,
comments or suggestions, email Mike Ritzwoller at ritzwoller@phys-geophys.colorado.edu
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