Slab Diffracted S Waves
{'Code': '06030204', 'Directorate': {'Abbreviation': 'GEO', 'LongName': 'Directorate For Geosciences'}, 'Division': {'Abbreviation': 'EAR', 'LongName': 'Division Of Earth Sciences'}}
{'SignBlockName': 'Patricia Brooking', 'PO_EMAI': None, 'PO_PHON': None}
Inversion of P wave arrival times has found that lithospheric slabs             frequently penetrate beyond the cutoff in the seismicity evident in             Wadati-Benioff zones.  Synthetic seismograms are calculated for                 teleseismic S waves radiated by a deep focus earthquake occurring               within a slab that penetrates to 1200 km depth.  The synthetics                 demonstrate a phenomenon of slab diffraction that acts to lengthen the          apparent pulse width of the S wave.  The slab diffraction is observed           in all azimuths on the dipping side of the slab evolving into a                 prominent secondary phase along strike, and rapidly decaying on the             side opposite to the dip.  Broadband S waves are shown, which suggest           the existence of slab diffraction in data.  Amplitude ratios used in            studies of mantle attenuation, D" structure, and core structure may             also be affected by the focusing and defocusing effects of the high             velocity perturbation of the slab.  It is proposed to use a                     WKBJ/Gaussian beam method to synthesize the effects of slab diffraction         in three-dimensional models in an effort to further constrain and               invert for slab structure.  An investigation will also be made of the           contaminating effects of slab structure in other studies of mantle and          core elastic and anelastic structure that use waveforms and amplitudes          of body waves from deep focus earthquakes.
{'FirstName': 'Vernon', 'LastName': 'Cormier', 'PI_MID_INIT': 'F', 'PI_SUFX_NAME': None, 'PI_FULL_NAME': 'Vernon F Cormier', 'EmailAddress': 'vernon.cormier@uconn.edu', 'NSF_ID': '000462494', 'StartDate': '09/01/1987', 'EndDate': None, 'RoleCode': 'Principal Investigator'}
{'Name': 'University of Connecticut', 'CityName': 'STORRS', 'ZipCode': '062699018', 'PhoneNumber': '8604863622', 'StreetAddress': '438 WHITNEY RD EXTENSION UNIT 11', 'StreetAddress2': None, 'CountryName': 'United States', 'StateName': 'Connecticut', 'StateCode': 'CT', 'CONGRESSDISTRICT': '02', 'CONGRESS_DISTRICT_ORG': 'CT02', 'ORG_UEI_NUM': 'WNTPS995QBM7', 'ORG_LGL_BUS_NAME': 'UNIVERSITY OF CONNECTICUT', 'ORG_PRNT_UEI_NUM': None}
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[{'Code': '157400', 'Text': 'Geophysics'}, {'Code': '912000', 'Text': 'CROSS-DIRECTORATE PROGRAMS'}]
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