{"id":{"repo_id":"unlv","oai_identifier":"oai:oasis.library.unlv.edu:rtds-1019"},"canonical_url":"https://search.dev.ndltd.org/etd/unlv/oai:oasis.library.unlv.edu:rtds-1019","repository":{"repo_id":"unlv","name":"University of Nevada - Las Vegas","base_url":"https://oasis.library.unlv.edu/do/oai/"},"display":{"title":"A comparison of three seismic methods in the arid environment","abstract":"Eight locations in the vicinity of Las Vegas, Nevada, were noise tested using a shotgun, high frequency geophones, and an engineering seismograph. The noise spreads were examined for reflection events to determine shotpoint to geophone offset for an optimum window reflection profile. No reflection events were observed in the noise spreads. Trial optimum offset lines were run at location 1 and location 8. The resulting profiles contain spurious reflecting horizons that appear to be teal reflectors. At the eighth location, a delay time profile and a series of over-lapping refraction soundings were performed at the site of the optimum offset line. The delay time profile contains false structure that is an artifact of error accumulation in data reduction. The over-lapping refraction soundings produced a useful low resolution profile of an alluvial contact approximately five to ten feet deep; The surface geologic environment in the southwestern desert was found to be unfavorable to the optimum offset reflection profiling method and the delay time method. Both yield misleading results when applied to shallow targets in the desert southwest. The refraction sounding technique provided useful profiles and should continue to be used in the southwest for profiling shallow refraction targets.","abstract_html":"Eight locations in the vicinity of Las Vegas, Nevada, were noise tested using a shotgun, high frequency geophones, and an engineering seismograph. The noise spreads were examined for reflection events to determine shotpoint to geophone offset for an optimum window reflection profile. No reflection events were observed in the noise spreads. Trial optimum offset lines were run at location 1 and location 8. The resulting profiles contain spurious reflecting horizons that appear to be teal reflectors. At the eighth location, a delay time profile and a series of over-lapping refraction soundings were performed at the site of the optimum offset line. The delay time profile contains false structure that is an artifact of error accumulation in data reduction. The over-lapping refraction soundings produced a useful low resolution profile of an alluvial contact approximately five to ten feet deep; The surface geologic environment in the southwestern desert was found to be unfavorable to the optimum offset reflection profiling method and the delay time method. Both yield misleading results when applied to shallow targets in the desert southwest. The refraction sounding technique provided useful profiles and should continue to be used in the southwest for profiling shallow refraction targets.","abstract_has_math":false,"creators":["Gahr, David A."],"institution":"University of Nevada, Las Vegas","degree_name":"Master of Science (MS)","degree_level":"Thesis","degree_discipline":"Geoscience","degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2007,"date_issued":"2007-01-01T08:00:00Z","date_published":"2007-01-01T08:00:00Z","updated_at":"2026-07-24T05:23:59Z","subjects":[],"languages":["English"],"rights":["IN COPYRIGHT. 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At the eighth location, a delay time profile and a series of over-lapping refraction soundings were performed at the site of the optimum offset line. The delay time profile contains false structure that is an artifact of error accumulation in data reduction. The over-lapping refraction soundings produced a useful low resolution profile of an alluvial contact approximately five to ten feet deep; The surface geologic environment in the southwestern desert was found to be unfavorable to the optimum offset reflection profiling method and the delay time method. Both yield misleading results when applied to shallow targets in the desert southwest. The refraction sounding technique provided useful profiles and should continue to be used in the southwest for profiling shallow refraction targets."]},{"key":"dc:format","label":"Dc Format","values":["pdf"]},{"key":"dc:title","label":"Title","values":["A comparison of three seismic methods in the arid environment"]}]}],"canonical_facts":{"dc:creator":["Gahr, David A."],"dc:description.abstract":["Eight locations in the vicinity of Las Vegas, Nevada, were noise tested using a shotgun, high frequency geophones, and an engineering seismograph. The noise spreads were examined for reflection events to determine shotpoint to geophone offset for an optimum window reflection profile. No reflection events were observed in the noise spreads. Trial optimum offset lines were run at location 1 and location 8. The resulting profiles contain spurious reflecting horizons that appear to be teal reflectors. At the eighth location, a delay time profile and a series of over-lapping refraction soundings were performed at the site of the optimum offset line. The delay time profile contains false structure that is an artifact of error accumulation in data reduction. The over-lapping refraction soundings produced a useful low resolution profile of an alluvial contact approximately five to ten feet deep; The surface geologic environment in the southwestern desert was found to be unfavorable to the optimum offset reflection profiling method and the delay time method. Both yield misleading results when applied to shallow targets in the desert southwest. The refraction sounding technique provided useful profiles and should continue to be used in the southwest for profiling shallow refraction targets."],"dc:format":["pdf"],"dc:identifier":["10.25669/qd0d-kd7s","https://oasis.library.unlv.edu/rtds/20","https://oasis.library.unlv.edu/context/rtds/article/1019/viewcontent/uc.pdf"],"dc:language":["English"],"dc:publisher":["University of Nevada, Las Vegas"],"dc:rights":["IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/"],"dc:title":["A comparison of three seismic methods in the arid environment"],"dc:type":["Text"],"thesis:degree_discipline":["Geoscience"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["Master of Science (MS)"]},"updated_at":"2026-07-24T05:23:59Z"}