- Home
- About Us
- News/TAG Webinars
- Membership
- Annual Meeting/SAGEEP
- Publications & Merchandise
- What is Geophysics?
Just-Accepted Journal ArticlesJust-Accepted Articles are peer-reviewed, accepted manuscripts that have been assigned Digital Object Identifiers (DOIs) and undergo the normal publication process (copy editing, page composition, proofing by author, and finalization). A Just-Accepted article listing includes an abstract and the DOI (scroll). The article is removed when the final version of the manuscript is ready and assigned to a Journal of Environmental & Engineering Geophysics (JEEG) issue, becoming the official version of the article. The Just Accepted article has the same DOI that appears on the official version of the article; therefore, citations made to an article during the Just-Accepted stage will continue to link to the article's official version. EEGS Members can access the full, preliminary article via this "member-only" link: Just-Accepted Articles with full article PDF Quantitative Assessment of Weathered Slope Soil Strength during Rainfall-runoff Processes Authors: DOI: 10.32389/JEEG22-049 ABSTRACT: In high-intensity rainstorms, weathered soil performance deteriorates with changes in soil mechanical properties caused by soil erosion, which will result in landslides. However, evaluation of weathered slope soil strength during rainfall-runoff processes is difficult. We proposed a temporal and spatial evaluation method of soil erosion and strength based on surface wave tests and three-dimensional (3-D) laser scanning. A rainfall experiment and a surface wave test were set up in a completely decomposed migmatitic granite slope of a highway. Shear wave velocity and rill distribution of slope during rainfall were obtained. With the increasing influence of infiltration and erosion, the shear wave velocity decreased from 105.8 m/s to 102.4 m/s, while the erosion rate increased slowly from 0% to 3.5%. The shear wave velocity decreased from 102.4 m/s to 97.3 m/s with an increase in erosion degree in the later stage, while the erosion rate increased rapidly from 3.5% to 7.1%. A correlation model between the erosion rate and shear wave velocity was obtained. With an increase in the erosion rate, the shear wave velocity decreased, which is related to the shear strength. A nonlinear decrease in soil shear strength at a certain depth increases the risk of sudden local collapse. Based on that, we can evaluate slope erosion degree by surface wave method and analyze the slope stability under rainfall erosion. Keywords: Weathered slope; Rainfall; Soil erosion; Model test; Soil strength
Field evaluation of two impulsive downhole seismic sources in crosswell and reverse VSP geometries and high-resolution characterization of near-surface Texas Gulf Coast sediments Authors: ABSTRACT: Borehole seismic methods have been widely used for characterizing the shallow subsurface. Accurate analysis of their data is aided by a solid understanding of the borehole sources’ characteristics. This study presents a field evaluation of two impulsive borehole seismic sources, (Trident's Scorpion sparker and RT Clark's Ballard weight drop) in crosswell and reverse vertical seismic profile (RVSP) geometries at a Gulf of Mexico coastal site with two shallow vertical wells. The data is then utilized to characterize the near-surface coastal sediments. The Scorpion source generated P-wave dominant frequencies that were recorded as 650 Hz and 250 Hz in the crosswell and RVSP geometries respectively. For Ballard source in the two geometries, the P-wave dominant frequencies were 1100 Hz and 250 Hz. We were also able to pick direct S-wave arrivals with the Ballard source and their dominant frequencies were 100 Hz and 40 Hz for in situ and surface recordings respectively. The average signal-to-noise ratio (SNR) recorded with the Scorpion data for the crosswell geometry and RVSP respectively is 13 and 6, and for the Ballard source 62 and 30. We also investigated the source radiation patterns and signature wavelets. Seismic tomography was performed for the area between the two wells. Low P-wave and S-wave velocities correspond to three fresh water-saturated sand zones identified from drilling cuttings and previous well log data. A Vp-Vs plot also fits reasonably to the Mudrock Line. Both sources can excite repeatable seismic signals up to 150m away and be useful in many geotechnical settings. Validation and Potential Improvement of Soil Survey Maps Using Proximal Soil Sensing Authors: Felippe Hoffmann Silva Karp; Viacheslav I. Adamchuk; Alex Melnitchouck; Barry Allred; Pierre Dutilleul; Luis R. Martinez Influence of Radiative Components and Meteorological Conditions on Simulation of Slope-Specific Heat Balance Research on Time-domain Airborne EM Full-field Apparent Resistivity Imaging Method for Arbitrary Transmitting Waveform Authors: Jianbo Zheng; Yanfu Qi DOI: 10.32389/JEEG22-023 ABSTRACT: The time-domain airborne electromagnetic (AEM) system can do fast EM surveys over mountainous areas by carrying its detection equipment on an airplane. Due to the dense sampling of AEM method, it generates a huge amount of data. As a result, the resistivity imaging methods have become the first choice for data interpretation because they are fast. However, the traditional imaging methods do not fully consider the influence of the transmitting waveform. When they are used to deal with the AEM data with complex current waveform, the imaging results are seriously affected. Therefore, we develop a universal full-field apparent resistivity imaging method for AEM data with arbitrary transmitting waveform. Firstly, we calculate the convolution of time derivative of the current waveform and step response to obtain the time-domain AEM response of the arbitrary transmitting waveform. Then the full-field apparent resistivity imaging method based on the inverse function theorem is used to complete the rapid imaging of AEM data with complex waveform. Finally, we apply our imaging codes to both synthetic and field data to verify its correctness. Keywords: Time-domain; Airborne EM; Transmitting waveform; Full-field apparent resistivity. Noise Reduction of Aeromagnetic Data Using Artificial Neural Network Authors: Osama Elghrabawy DOI: 10.32389/JEEG22-013
|