[1] Imaging of seismic velocity discontinuities along a 3000 km profile across central South America at 20 S suggests that the depth variations of the 410-km (d410) and 660-km (d660) discontinuities are closely associated with the high-velocity Nazca slab and juxtaposed low-velocity oceanic mantle beneath the slab. The mantle transition zone thickness ranges from 220 km in the oceanic mantle to...

In this paper we present seismic signature simulations using ground vibration inputs from highfidelity 3-D mechanical system models. Results for an M1A1 and T72 are discussed. By analyzing the simulated seismic signature data in conjunction with the spectral features associated with the vibrations of specific vehicle sprung and un-sprung components we are able to make unambiguous associations o...

[i] We show that ocean temperature profiles can be accurately recovered using only acoustic methods employed at the sea surface. Using a towed air gun array and a hydrophone streamer, thermohaline boundaries are ensonified at a suite of frequencies and angles, yielding travel time trajectories and reflectivities. These data are inverted via full waveform inversion to estimate sound speed and, s...

Seismic oceanographic studies from various oceans worldwide have indicated that the acoustic reflections are mostly observed along thermal boundaries within the water column. However, the authors present a case study of seismic data from Krishna-Godavari Basin which shows that salinity variations also play an important role in the occurrence of water column reflections. The observed reflection ...

S U M M A R Y Converted phase (CP) elastic seismic signals are comparable in amplitude to the primary signals recorded at large offsets and have the potential to be used in seismic imaging and velocity analysis. We present an approach for CP elastic wave equation velocity analysis that does not use source information and is applicable to surface-seismic, microseismic, teleseismic and vertical s...

Ahmadi, O. 2015. Application of the Seismic Reflection Method in Mineral Exploration and Crustal Imaging. Contributions to Hardrock Seismic Imaging. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1269. 76 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-554-9290-8. The seismic reflection method has been used extensively in mineral exp...

This dissertation consists of four research topics, addressing three different scales of crustal-scale seismic data analysis. At the large scale, this research involves determining the lithospheric crustal structure across the southern Rio Grande rift (SRGR) from a 205 km long refraction/wide-angle reflection profile across southern New Mexico into Far West Texas acquired during the Portillo Vo...

Characterisation of the heterogeneous naturally fractured reservoirs is an essential and significantly challenging task, especially due to the limited data availability. This paper presents a foundation relationship between P-wave / S-wave velocity and formation resistivity for improved fracture characterisation. Rock matrix and fluid volumetrics are combined with the basic correspondence betwe...