Browsing NTNU Open by Author "Wehner, Daniel"
Now showing items 1-7 of 7
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Acoustic signals in air and water generated by very shallow marine seismic sources: An experimental study
Wehner, Daniel; Svensson, U. Peter; Landrø, Martin (Peer reviewed; Journal article, 2020)When a marine seismic source, like an airgun, is fired close to the water surface the oscillating bubble interacts with the water–air interface. The main interest for seismic applications is how this effect impacts the ... -
Experimental Studies of the Acoustic Signal generated by Marine Seismic Sources
Wehner, Daniel (Doctoral theses at NTNU;2019:80, Doctoral thesis, 2019)Marine seismic acquisition is the most commonly used geophysical technique to image the subsurface for different purposes, e.g. exploration of reservoirs or investigation of subduction zones as areas where earthquakes are ... -
Frequency-depth-dependent spherical reflection response from the sea surface - a transmission experiment
Wehner, Daniel; Landrø, Martin; Amundsen, Lasse; Westerdahl, Harald (Journal article; Peer reviewed, 2018)In academia and the industry, there is an increasing interest in generating and recording low seismic frequencies, which lead to better data quality, deeper signal penetration and can be important for full-waveform inversion. ... -
Gas flow through shallow sediments - A case study using passive and active seismic field data
Landrø, Martin; Wehner, Daniel; Vedvik, Noralf; Ringrose, Philip; Løhre, Nora Løw; Berteussen, Karl-Andreas (Journal article; Peer reviewed, 2019)Offshore Quaternary sediment sequences are generally weak and unconsolidated, and fluid flow through these rock formations is hard to predict or model. Surface flow observations, such as gas seeps, often appear random and ... -
Low-frequency acoustic signal created by rising air-gun bubble
Wehner, Daniel; Landrø, Martin (Journal article; Peer reviewed, 2017)In the seismic industry, there is increasing interest in generating and recording low frequencies, which leads to better data quality and can be important for full-waveform inversion. The air gun is a seismic source with ... -
On low frequencies emitted by air guns at very shallow depths - An experimental study
Wehner, Daniel; Landrø, Martin; Amundsen, Lasse (Journal article; Peer reviewed, 2019)In marine seismic acquisition, the enhancement of frequency amplitudes below 5 Hz is of special interest because it improves imaging of the subsurface. The frequency content of the air gun, the most commonly used marine ... -
Tube-wave monitoring as a method to detect shear modulus changes around boreholes: A case study
Wehner, Daniel; Borges, Filipe; Landrø, Martin (Peer reviewed; Journal article, 2021)Monitoring the shear modulus of formations around boreholes is of interest for various applications, ranging from near-surface investigation to reservoir monitoring. Downhole logging tools and borehole seismic are common ...