Blar i Bergen Open Research Archive på forfatter "Johansen, Tor Arne"
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Case study of combined marine- and land-based passive seismic surveying in front of Nordenskiöldbreen outlet glacier, Adolfbukta, Svalbard
Stemland, Helene; Ruud, Bent Ole; Johansen, Tor Arne (Journal article; Peer reviewed, 2023)Glaciers generate seismic waves due to calving and fracturing, meaning that recording and following event classification can be used to monitor glacier dynamics. Our aim with this study is to analyse seismic data acquired ... -
Characterization of seabed properties from Scholte waves acquired on floating ice on shallow water
Johansen, Tor Arne; Ruud, Bent Ole (Journal article; Peer reviewed, 2020)Seismic surveying of the coastal areas in the Arctic is best facilitated during wintertime when the sea ice is land-fast. This eases the logistics of the operation and assures that there is no damage made to the vulnerable ... -
Diagnostics of seismic time-lapse effects of sandstones based on laboratory data
Moyano, Bernardo; Johansen, Tor Arne; Agersborg, Remy; Spikes, Kyle Thomas (Peer reviewed; Journal article, 2014-09)We evaluated a viscoelastic modeling of P- and S-wave velocity dispersion, attenuation, pressure, and fluid effects for a set of siliciclastic rock samples. Our analysis used a published laboratory data set of 63 sandstones ... -
Estimation of elastic moduli of mixed porous clay composites
Jensen, Erling Hugo; Andersen, Charlotte Faust; Johansen, Tor Arne (Peer reviewed; Journal article, 2011-01-13)We have developed a procedure for estimating the effective elastic properties of various mixtures of smectite and kaolinite over a range of confining pressures, based on the individual effective elastic properties of pure ... -
Improved quantitative calibration of rock physics models
Moyano, Bernardo; Jensen, Erling Hugo; Johansen, Tor Arne (Peer reviewed; Journal article, 2011-11)In reservoir characterization, rock-physics models provide the link between seismic observables (density, compressional and shear wavespeeds) and reservoir parameters such as porosity, lithology and fluid saturation. ... -
Modeling compaction effects on the elastic properties of clay-water composites
Moyano, Bernardo; Spikes, Kyle Thomas; Johansen, Tor Arne; Mondol, Nazmul Haque (Peer reviewed; Journal article, 2012-09)Modeling the elastic properties of clay-bearing rocks (shales) requires thorough knowledge of the mineral constituents, their elastic properties, pore space microstructure, and orientations of clay platelets. Information ... -
Passive seismic recording of cryoseisms in Adventdalen, Svalbard
Romeyn, Rowan; Hanssen, Alfred; Ruud, Bent Ole; Stemland, Helene Meling; Johansen, Tor Arne (Journal article; Peer reviewed, 2021)A series of transient seismic events were discovered in passive seismic recordings from 2-D geophone arrays deployed at a frost polygon site in Adventdalen, Svalbard. These events contain a high proportion of surface wave ... -
Potential Use of Time-Lapse Surface Seismics for Monitoring Thawing of the Terrestrial Arctic
Stemland, Helene Meling; Johansen, Tor Arne; Ruud, Bent Ole (Journal article; Peer reviewed, 2020)The terrestrial Arctic is warming rapidly, causing changes in the degree of freezing of the upper sediments, which the mechanical properties of unconsolidated sediments strongly depend upon. This study investigates the ... -
Quantitative interpretation using inverse rock-physics modeling on AVO data
Jensen, Erling Hugo; Johansen, Tor Arne; Avseth, Per; Bredesen, Kenneth (Peer reviewed; Journal article, 2016-08)Quantitative seismic interpretation has become an important and critical technology for improved hydrocarbon exploration and production. However, this is typically a resource-demanding process that requires information ... -
Quantitative interpretation using inverse rock-physics modeling on AVO data
Jensen, Erling Hugo; Johansen, Tor Arne; Avseth, Per Åge; Bredesen, Kenneth (Peer reviewed; Journal article, 2016-08)Quantitative seismic interpretation has become an important and critical technology for improved hydrocarbon exploration and production. However, this is typically a resource-demanding process that requires information ... -
Rock physics interpolation Used for velocity modeling of chalks: Ontong Java plateau example
Saberi, Mohammad Reza; Johansen, Tor Arne; Sælen, Gunnar (Peer reviewed; Journal article, 2010)Chalks are pelagic carbonate sediments that are deposited in deep-water environments. Their elastic behaviour is controlled by a combination of depositional conditions and subsequent diagenesis. In this paper, we incorporate ... -
Sea ice thickness from air-coupled flexural waves
Romeyn, Rowan; Hanssen, Alfred; Ruud, Bent Ole; Johansen, Tor Arne (Journal article; Peer reviewed, 2021)Air-coupled flexural waves (ACFWs) appear as wave trains of constant frequency that arrive in advance of the direct air wave from an impulsive source travelling over a floating ice sheet. The frequency of these waves varies ... -
Seismic on floating ice: data acquisition versus flexural wave noise
Johansen, Tor Arne; Ruud, Bent Ole; Tømmerbakke, Ronny; Jensen, Kristian (Journal article; Peer reviewed, 2019)Geophysical surveying of the Arctic will become increasingly important in future prospecting and monitoring of the terrestrial and adjacent areas in this hemisphere. Seismic data acquired on floating ice are hampered with ... -
Seismic reservoir and source-rock analysis using inverse rock-physics modeling: A Norwegian Sea demonstration
Bredesen, Kenneth; Jensen, Erling Hugo; Johansen, Tor Arne; Avseth, Per (Peer reviewed; Journal article, 2015-11)Identifying type of rocks and fluids from seismic-amplitude anomalies can be challenging because of seismic nonuniqueness and rock-physics ambiguities. Lithology and fluid predictions based on seismic properties therefore ... -
Simultaneous tracking of multiple whales using two fiber-optic cables in the Arctic
Rørstadbotnen, Robin Andre; Eidsvik, Jo; Bouffaut, Léa; Landrø, Martin; Potter, John Robert; Taweesintananon, Kittinat; Johansen, Ståle Emil; Storvik, Frode; Jacobsen, Joacim; Schjelderup, Olaf; Wienecke, Susann; Johansen, Tor Arne; Ruud, Bent Ole; Wuestefeld, Andreas; Oye, Volker (Journal article; Peer reviewed, 2023-04-28)Climate change is impacting the Arctic faster than anywhere else in the world. As a response, ecosystems are rapidly changing. As a result, we can expect rapid shifts in whale migration and habitat use concurrent with ...