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Data from the PASSCAL NOMAD Experiment, Southern New York

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Abstract: STS-2s were deployed at four sites in southern New York (VASR, WIND,
WICK, and SCCC) in June, 1997. The instruments at VASR and WIND were
moved to UCON and UHRT in October, 1998, and the experiment ended in
February, 1999. Data was recorded continuously at 20 sps and 1
sps. Preliminary results: Shear-wave splitting measurements reveal
variations in upper mantle anisotropy over length scales of roughly 50
km. These results, combined with other eastern North American
shear-wave splitting measurements and inversion of Rayleigh wave data,
are best explained by a combination of asthenospheric flow and
lithospheric deformation. Splitting in core-diffracted shear phases
requires strong variations in anisotropy near the core-mantle boundary
beneath the Pacific.
Geographic Coverage
Spatial coordinates   
  N: 42.45   S: 41.67   E: -72.22   W: -74.93

Data Set Citation
Dataset Originator/Creator: Karen M. Fischer, Brown University
Dataset Title: NOMAD
Dataset Publisher: IRIS > Incorporated Research Institutions for Seismology
Temporal Coverage
Start Date: 1997-06-03
Stop Date: 1999-02-22
ISO Topic Category
SEISMOMETERS Ancillary Description
Quality For the following time periods, GPS clocks failed to lock in such a
way that time corrections for clock drift were not possible:
WICK (julian days 97264-97291, 97356-98029, 98097-98131, 98140-98156,
99043-99052); VASR (98156-98214).
Access Constraints None
Use Constraints Please cite data properly
Data Set Progress
Originating Center
Data Center
PASSCAL Instrument Center, Incorporated Research Institutions for Seismology Supplemental Info
Data Center URL:
Dataset ID: PASSCAL XO 97-99/Nomad

Data Center Personnel
Phone: (505) 835-5070
Fax: (505) 835-5079
Email: passcal at
Contact Address:
PASSCAL Instrument Center
New Mexico Tech
100 East Road
City: Socorro
Province or State: NM
Postal Code: 87801
Country: USA
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Distribution Format: SEED
Phone: 401-863-1360
Email: Karen_Fischer at Brown.EDU
Contact Address:
Geological Sciences Department
Brown University
Box 1846
City: Providence
Province or State: Rhode Island
Postal Code: 02912-1846
Country: USA
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Fouch, M. J., K. M. Fischer, and M. E. Wysession. Three-dimensional
variations in lowermost mantle shear wave anisotropy beneath the
Pacific, Earth Planet. Sci. Lett., in press, 2000.

Fouch, M. J., K. M. Fischer, E. M. Parmentier, M. E. Wysession, and
T. J. Clarke. Shear-wave splitting, continental keels, and patterns of
mantle flow, J. Geophys. Res., 105, 6255-6275, 2000.
Extended Metadata Properties
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Creation and Review Dates
DIF Creation Date: 2001-03-31
Last DIF Revision Date: 2016-11-18
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