Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Accueil du site → Master → Etats Unis → 1989 → A comparison of three seismic methods in the arid environment

University of Nevada, Las Vegas (1989)

A comparison of three seismic methods in the arid environment

Gahr, David A

Titre : A comparison of three seismic methods in the arid environment

Auteur : Gahr, David A

Université de soutenance : University of Nevada, Las Vegas

Grade : M.S. Geoscience 1989

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.


Accès au document : Proquest Dissertations & Theses

Page publiée le 29 janvier 2015, mise à jour le 20 février 2018