scholarly journals Gas diffusivity‐based characterization of aggregated soils linking to methane migration in shallow subsurface

2021 ◽  
Author(s):  
M. Shanujah ◽  
Chamindu Deepagoda ◽  
Kathleen M. Smits ◽  
V. Shreedharan ◽  
T. G. Paramrswaran ◽  
...  
Keyword(s):  
Shallow Subsurface ◽  
Gas Diffusivity

scholarly journals Delineating shallow Neogene deformation structures in northeastern Pará State using Ground Penetrating Radar

2003 ◽  
Vol 75 (2) ◽  
pp. 235-248 ◽  
Author(s):  
Dilce F. Rossetti
Keyword(s):  
Ground Penetrating Radar ◽  
Structural Models ◽  
Field Studies ◽  
Strike Slip ◽  
Brittle Deformation ◽  
Shallow Subsurface ◽  
Deformation Structures ◽  
Ground Penetrating ◽  
Slip Motion

The geological characterization of shallow subsurface Neogene deposits in northeastern Pará State using Ground Penetrating Radar (GPR) revealed normal and reverse faults, as well as folds, not yet well documented by field studies. The faults are identified mostly by steeply-dipping reflections that sharply cut the nearby reflections causing bed offsets, drags and rollovers. The folds are recognized by reflections that are highly undulating, configuring broad concave and convex-up features that are up to 50 m wide and 80 to 90 ns deep. These deformation structures are mostly developed within deposits of Miocene age, though some of the faults might continue into younger deposits as well. Although the studied GPR sections show several diffractions caused by trees, differential degrees of moisture, and underground artifacts, the structures recorded here can not be explained by any of these ''noises''. The detailed analysis of the GPR sections reveals that they are attributed to bed distortion caused by brittle deformation and folding. The record of faults and folds are not widespread in the Neogene deposits of the Bragantina area. These GPR data are in agreement with structural models, which have proposed a complex evolution including strike-slip motion for this area from the Miocene to present.

Gas Diffusivity-Based Design and Characterization of Greenhouse Growth Substrates

2013 ◽  
Vol 12 (3) ◽  
pp. vzj2013.03.0061 ◽  
Author(s):  
T.K.K. Chamindu Deepagoda ◽  
Per Moldrup ◽  
Markus Tuller ◽  
Mette Pedersen ◽  
Jose Choc Chen Lopez ◽  
...  
Keyword(s):  
Gas Diffusivity ◽  
Growth Substrates

High-resolution Seismic Characterization of the Shallow Subsurface Applied to Civil Engineering

2015 ◽  
Author(s):  
D. Martí Linares ◽  
I. Marzán ◽  
J. Sachsenhausen ◽  
J. Álvarez-Marrón ◽  
I. Cienfuegos ◽  
...  
Keyword(s):  
High Resolution ◽  
Civil Engineering ◽  
Shallow Subsurface ◽  
Seismic Characterization

EMI characterization in mountain catchments: multi-frequency versus multi-coil inversion using EMagPy

2021 ◽  
Author(s):  
Guillaume Blanchy ◽  
Paul McLachlan ◽  
Matteo Censini ◽  
Jacopo Boaga ◽  
Andrew Binley ◽  
...  
Keyword(s):  
Open Source Software ◽  
Single Frequency ◽  
Shallow Subsurface ◽  
Mountainous Catchments ◽  
Rugged Topography ◽  
Vertical Changes ◽  
Multiple Frequencies ◽  
Multiple Receiver ◽  
Synthetic Modeling

<p>Advanced modeling of hydrological processes in mountain catchments requires accurate characterization of the shallow subsurface, and in particular the depth to the soil/bedrock interface. Frequency domain electromagnetic induction (EMI) methods are well suited to this challenge as they have short acquisition times and do not require direct coupling with the ground; consequently they can be highly productive. Moreover, although traditionally used for revealing lateral electrical conductivity changes, EMI inversion is increasingly used to quantitatively resolve both lateral and vertical changes. These quantitative models can then be used to inform several properties relevant for hydrological modelling (e.g. water content, permeability).</p><p>In this work the open-source software EMagPy is used to compare between EMI data collected with a multi-coil device (i.e. a single frequency device with multiple receiver coils) and a multi-frequency device (i.e. a single inter-coil distance and multiple frequencies). The latter instrument is easier to handle because of its shorter length and lower weight, and thus it is potentially more suitable for the rugged topography of mountain slopes. However it is important to compare the value of information (e.g. sensitivity patterns and data quality) obtained from both instruments.</p><p>To begin with, the performance of both devices is assessed using synthetic modeling. Following from this the analysis is focused on two mountainous catchments: one located in the Alpine region above 2000 m a.s.l., the other in a Mediterranean catchment in Southern Italy. Both sites have differing geological and hydrological conditions and provide a useful comparison to determine the suitability of multi-frequency and multi-coil devices, and highlight necessary considerations of EMI acquisition.</p>

scholarly journals Characterization of Grain-Size Distribution, Thermal Conductivity, and Gas Diffusivity in Variably Saturated Binary Sand Mixtures

2018 ◽  
Vol 17 (1) ◽  
pp. 180026 ◽  
Author(s):  
T.K.K. Chamindu Deepagoda ◽  
Kathleen Smits ◽  
J.R.R.N. Jayarathne ◽  
Benjamin M. Wallen ◽  
Timothy J. Clough
Keyword(s):  
Thermal Conductivity ◽  
Grain Size ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Gas Diffusivity

scholarly journals Gas‐Diffusivity based characterization of aggregated agricultural soils

2020 ◽  
Vol 84 (2) ◽  
pp. 387-398 ◽  
Author(s):  
J. R. R. N. Jayarathne ◽  
T. K. K. Chamindu Deepagoda ◽  
Timothy J. Clough ◽  
M.C.M. Nasvi ◽  
Steve Thomas ◽  
...  
Keyword(s):  
Agricultural Soils ◽  
Gas Diffusivity
Sign in / Sign up

Export Citation Format

Share Document