Application of high resolution multichannel seismic techniques to offshore site investigation studies

2017 ◽  
Vol 15 (4) ◽  
pp. 335-345 ◽  
Author(s):  
Olivier Monrigal ◽  
Ivan de Jong ◽  
Henrique Duarte

1994 ◽  
Vol 29 (8) ◽  
pp. 161-172 ◽  
Author(s):  
D. C. Gomes ◽  
M. Alarsa ◽  
M. C. Salvador ◽  
C. Kupferschmid

The PETREX Passive Soil Gas Technique - applied successfully to environmental projects for 10 years - is the ideal primary investigative tool for soil and groundwater contaminations, since it is rapid, easy to apply and covers large areas. It is more sensitive and cost effective than other methods (e.g. active soil gas techniques). Passive collectors combined with high-resolution mass spectrometry permit direct mid reliable identification of over 9,000 volatile (VOCs) and semi-volatile organic compounds (SVOCs). PETREX is capable of providing comprehensive problem delineation during the initial stages of the site investigation, allowing for greater cost effectiveness in the planning of remediation programs and in the selection of appropriate monitoring well locations and other methodologies which may be needed to complete the environmental evaluation. PETREX therefore finds wide use in the investigation of contaminants, in the determination of pollution sources, as well as in audits connected to real estate transactions. This paper describes a case-study developed in Brazil, showing PETREX's usefulness and its correlation with soil and groundwater contamination plumes established from traditional direct sampling methods.


2021 ◽  
Author(s):  
Damian Pasiecznik ◽  
Andrew Greenwood ◽  
Baron Ludovic ◽  
Bleibinhaus Florian ◽  
Hetényi György

<p>The Ivrea Verbano Zone (IVZ) is one of the most complete crust–upper mantle geological references in the world, and the Drilling the Ivrea-Verbano zone project (DIVE) aims to unravel the uncertainties below this area. Geophysical anomalies detected across the IVZ indicate that dense, mantle-like rocks are located at depths as shallow as ca. 3km. Thus, several geological, geochemical and geophysical studies are planned, including the drilling of a 4km deep borehole that will penetrate the Balmuccia Peridotite (Val Sesia, Italy) to approach and possibly cross the crust–mantle transition zone, and provide, for the first time, geophysical in-situ measurements of the IVZ.</p><p>One of the primary requirements before drilling is a seismic site characterization, to define with precision the correct positioning and orientation of the borehole, to assess potential drilling hazards and to allow for the spatial extrapolation of the borehole logs. For that goal, two joint geophysical surveys were performed in October 2020 in a collaboration of GFZ Potsdam, Université de Lausanne and Montanuniversität Leoben. First: a deep seismic survey, entitled SEIZE (SEismic imaging of the Ivrea ZonE), consisting of two approximately 15km-long seismic lines performed by GFZ Potsdam, that aim to resolve the deeper structure of the IVZ in the area, and second: a static seismic survey at the proposed drill site, entitled HiSEIZE (High-resolution SEismic imaging of the Ivrea ZonE), geared towards providing high-resolution seismic images of the uppermost few km at the proposed drill site.</p><p>The HiSEIZE survey, the subject of this study, was performed with a fixed spread of 200 vertical geophones and 160 3C-sensors, spaced at ca. 11m along three sub-parallel lines spaced 50-80m apart. Vibroseis source points were at 22m stations along a 2.4km line utilizing a high-frequency (12-140 Hz) 10s linear sweep with 3s listening time. In addition to this, the HiSEIZE receiver spread was active during the deep SEIZE survey, information that may be useful in determination of a velocity model through the Balmuccia Peridotite.</p><p>This project will not only provide site characterization for the DIVE project, but also contribute to understanding the structure of the Balmuccia Peridotite, its changes in depth and its relationship with the crustal-mantle transition.</p><p>Here we present the data and discuss the challenges of 3D pre-stack-imaging in an area of extreme topography.</p>


1967 ◽  
Vol 31 ◽  
pp. 45-46
Author(s):  
Carl Heiles

High-resolution 21-cm line observations in a region aroundlII= 120°,b11= +15°, have revealed four types of structure in the interstellar hydrogen: a smooth background, large sheets of density 2 atoms cm-3, clouds occurring mostly in groups, and ‘Cloudlets’ of a few solar masses and a few parsecs in size; the velocity dispersion in the Cloudlets is only 1 km/sec. Strong temperature variations in the gas are in evidence.


2019 ◽  
Vol 42 ◽  
Author(s):  
J. Alfredo Blakeley-Ruiz ◽  
Carlee S. McClintock ◽  
Ralph Lydic ◽  
Helen A. Baghdoyan ◽  
James J. Choo ◽  
...  

Abstract The Hooks et al. review of microbiota-gut-brain (MGB) literature provides a constructive criticism of the general approaches encompassing MGB research. This commentary extends their review by: (a) highlighting capabilities of advanced systems-biology “-omics” techniques for microbiome research and (b) recommending that combining these high-resolution techniques with intervention-based experimental design may be the path forward for future MGB research.


1994 ◽  
Vol 144 ◽  
pp. 593-596
Author(s):  
O. Bouchard ◽  
S. Koutchmy ◽  
L. November ◽  
J.-C. Vial ◽  
J. B. Zirker

AbstractWe present the results of the analysis of a movie taken over a small field of view in the intermediate corona at a spatial resolution of 0.5“, a temporal resolution of 1 s and a spectral passband of 7 nm. These CCD observations were made at the prime focus of the 3.6 m aperture CFHT telescope during the 1991 total solar eclipse.


1994 ◽  
Vol 144 ◽  
pp. 541-547
Author(s):  
J. Sýkora ◽  
J. Rybák ◽  
P. Ambrož

AbstractHigh resolution images, obtained during July 11, 1991 total solar eclipse, allowed us to estimate the degree of solar corona polarization in the light of FeXIV 530.3 nm emission line and in the white light, as well. Very preliminary analysis reveals remarkable differences in the degree of polarization for both sets of data, particularly as for level of polarization and its distribution around the Sun’s limb.


Sign in / Sign up

Export Citation Format

Share Document