Sökning: "Ari Tryggvason"

Visar resultat 1 - 5 av 13 avhandlingar innehållade orden Ari Tryggvason.

1. 1. Seismic tomography : Inversion for P- and S-wave velocities

   Författare :Ari Tryggvason; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; Geovetenskap; Earth sciences; Geovetenskap; Geofysik med inriktning mot seismologi; Geophysics with specialization in Seismology;

   Sammanfattning : Seismology is undoubtedly the most powerful method for determining the structure of the Earth below the deepest borehole. This thesis describes the, use of seismic signals from both man-made and earthquake sources to model seismic velocities within a volume of the Earth. LÄS MER

3. 2. High-Resolution Seismics Methods Applied to Till Covered Hard Rock Environments

   Författare :Björn Bergman; Christopher Juhlin; Laust Börsting Pedersen; Ari Tryggvason; Ramon Carbonell; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geophysics; High-Resolution; Reflection Seismics; Tomography; Nuclear waste repository; Bedrock; Sediments; Geofysik; Geophysics; Geofysik;

   Sammanfattning : Reflection seismic and seismic tomography methods can be used to image the upper kilometer of hard bedrock and the loose unconsolidated sediments covering it. Developments of these two methods and their application, as well as identifying issues concerning their usage, are the main focus of the thesis. LÄS MER

4. 3. Reflection seismic investigation in the Skellefte ore district : A basis for 3D/4D geological modeling

   Författare :Mahdieh Dehghannejad; Christopher Juhlin; Ari Tryggvason; Charles Hurich; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Skellefte district; reflection seismic; mineral exploration; 3D 4D modeling; mineralization; faults and shear zones; Geofysik med inriktning mot fasta jordens fysik; Geophysics with specialization in Solid Earth Physics;

   Sammanfattning : The Skellefte ore district in northern Sweden is a Palaeoproterozoic volcanic arc and one of the most important ones hosting volcanogenic massive sulfide (VMS) deposits, producing mainly base metals and orogenic gold deposits. Due to high metal prices and increased difficulties in finding shallow deposits, the exploration for and exploitation of mineral resources is quickly being moved to greater depths. LÄS MER

5. 4. Investigating Time-Varying Processes Using Seismicity and Time-Dependent Tomography

   Författare :Alex Hobé; Ari Tryggvason; Olafur Gudmundsson; Roland Roberts; Nicholas Rawlinson; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Time-Dependent Tomography; Joint Inversion; Geothermal Energy; Volcanotectonics; Seismic Unrest; Fagradalsfjall Eruption; Geofysik med inriktning mot seismologi; Geophysics with specialization in Seismology;

   Sammanfattning : Our global society is affected by, and makes use of, many time-varying processes. Processes related to geothermal energy and CO2 sequestration can help mitigate climate change and reduce the number of premature deaths (millions annually) due to air pollution from fossil fuels. LÄS MER

7. 5. 3D Time-lapse Analysis of Seismic Reflection Data to Characterize the Reservoir at the Ketzin CO2 Storage Pilot Site

   Författare :Fei Huang; Christopher Juhlin; Alireza Malehmir; Ari Tryggvason; Andy Chadwick; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; CO2 storage; 3D Time-lapse 4D ; Reservoir characterization; Seismic simulation; Spectral decomposition; Wavelet phase; Tuning frequency; Thin-layer thickness; Seismic monitoring; Seismic processing; Quantitative interpretation; Geofysik med inriktning mot fasta jordens fysik; Geophysics with specialization in Solid Earth Physics;

   Sammanfattning : 3D time-lapse seismics, also known as 4D seismics, have great potential for monitoring the migration of CO2 at underground storage sites. This thesis focuses on time-lapse analysis of 3D seismic reflection data acquired at the Ketzin CO2 geological storage site in order to improve understanding of the reservoir and how CO2 migrates within it. LÄS MER