Blar i NGU Open Archive på forfatter "Tassis, Georgios"
-
Helicopter-borne magnetic, electromagnetic and radiometric geophysical syrvey of Stjernøy, Finnmark County
Tassis, Georgios; Rodionov, Alexei; Ofstad, Frode; Stampolidis, Alexandros (NGU-Rapport (2014.033), Report, 2014)NGU conducted an airborne geophysical survey at Stjernøy Finnmark in September 2013 and August 2014 as a part of the MINN project. This report describes and documents the acquisition, processing and visualization of recorded ... -
Helicopter-borne magnetic, electromagnetic and radiometric survey at Northern Senja in 2012, 2013 and 2014, Troms County
Rodionov, Alexei: Ofstad, Frode; Tassis, Georgios; Stampolidis, Alexandros (NGU-Rapport (2014.039), Report, 2014)As a part of the MINN project, NGU conducted an airborne geophysical survey at Senja in July-August 2012 and August 2013 (Rodionov et al. 2013). For special reasons, a small area were not measured until September 2014. ... -
Kvalitet på tolket seismikk : eksempler fra E39 kryssing av Romsdalsfjorden
Rønning, Jan S.; Tassis, Georgios; Kavli, Arne; Åndal, Torkild; Olsen, Fredrik, W.G.; Wisén, Roger (NGU-Rapport (2020.040), Report, 2021)NGU har, som deltager i "Ekspertgruppe for ingeniørgeologi" ved prosjektet E39 Kryssing av Romsdalsfjorden, fått tilgang til mye resultater fra refraksjonsseismikk utførte av flere aktører samt boringer utført av Statens ... -
Kvartærgeologi og hydrogeologi ved Kråkneset i Altafjorden. Innspill til utredning av Kråknesskredet, 3. juni 2020
Hansen, Louise; Dagestad, Atle; Tassis, Georgios; Eilertsen, Raymond S. (NGU-Rapport (2020.029), Report, 2020)Denne rapporten oppsummerer de kvartærgeologiske og hydrogeologiske forholdene ved Kråkneset i Altafjorden i Finnmark der det 3. juni 2020 gikk et større løsmasseskred ved Flatstrand. Rapporten er bestilt som innspill til ... -
Mapping of fracture zones using resistivity method between islands at Arsvågen, Bokn municipality, Rogaland - ROGFAST project
Dalsegg, Einar; Tassis, Georgios; Rønning, Jan Steinar; Larsen, Bjørn Eskil (NGU-Rapport (2014.049), Report, 2015)This survey was carried out in cooperation with the Norwegian Public Roads Administration (Statens vegvesen) to aid and supplement the construction of a major tunnel in Arsvågen, Rogaland. Essentially, this work follows ... -
Quaternary mapping at Orkdal, Orkland municipality with the use of Georadar measurements, 2016 - 2019
Tassis, Georgios (NGU-Rapport (2020.039), Report, 2021)Between November 2016 and November 2019, NGU carried out Georadar measurements in several localities in Orkland municipality in connection with mapping of Quaternary sediments. Specifically, GPR lines were measured at the ... -
Refraction seismic modeling and inversion for the detection of fracture zones in bedrock with the use of Rayfract® software
Tassis, Georgios; Rohdewald, Siegfried; Rønning, Jan Steinar (NGU-Rapport (2017.025), Report, 2017)In this report we have investigated the response of several synthetic models of variable complexity to tomographic inversion using the Rayfract\u00AE Software. Through this process it has been clearly demonstrated that ... -
Reprocessing of ERT data from Åknes, Stranda Municipality, Møre and Romsdal County
Rønning, Jan Steinar; Tassis, Georgios (NGU-Rapport (2018.002), Report, 2018)NGU performed consecutive geophysical investigations in the Åknes area from 2004 until 2007 in connection with the Åknes\/Tafjord project. These investigations consisted of 10 km of ERT profiling distributed in 10 profiles, ... -
Reprosessering og ny samtolking av geofysiske data med resultater fra tunneldriving, Knappetunnelen ved Ringveg Vest i Bergen.
Rønning, Jan S.; Wåle, Morgan; Kirkeby, Terje; Tassis, Georgios (NGU-Rapport (2019.014), Report, 2019)Refraksjonsseismiske data, samlet inn som en del av forundersøkelsene for den 3,8 km lange nordlige delen av Knappetunnelen ved Ringveg vest i Bergen, er tolket med tomografisk inversjon med programmet RayfractTM. Samtidig ... -
Reprosessing of refraction seismic data from Åknes, Stranda municipality, Møre og Romsdal
Tassis, Georgios; Rønning, Jan Steinar (NGU-Rapport (2019.004), Report, 2019)In continuation to the various ground geophysics data collected at the unstable rock slope area at Åknes during the past 15 years, NVE commissioned GeoExpert AG from Switzerland to perform additional seismic investigations. ... -
Retolkning av geofysiske data og sammenligning med resultater fra tunneldriving, Knappetunnelen ved Ringveg Vest i Bergen
Rønning, Jan S.; Wåle, Morgan; Kirkeby, Terje; Tassis, Georgios (NGU-Rapport (2016.048), Report, 2016)Refraksjonsseismiske data samlet inn som en del av forundersøkelsene for den 3,8 km lange Knappetunnelen ved Ringveg vest i Bergen, er tolket med tomografisk inversjon hvor en benyttet programmet RayfractTM. Samtidig er ... -
Testing the performance of Fuzzy C-means data clustering approach in the detection of weak zones in bedrock for the case of Knappe tunnel (ForForUT project)
Tassis, Georgios; Wang, Ying; Rønning, Jan Steinar (NGU-Rapport (2022.003), Report, 2023)Near-surface geophysical applications employing multiple 2D methods that are mapping multiple properties along co-located profiles, enable new possibilities in exploring subsurface structures. Diverse data sets can now be ... -
Tomographic inversion of synthetic refraction seismic data using various starting models in Rayfract® software
Tassis, Georgios; Rønning, Jan Steinar; Rohdewald, Siegfried (NGU-Rapport (2018.015), Report, 2018)This report continues our work on refraction seismic modeling in Rayfract\u00AE and explores new possibilities offered by the software to create reliable starting models for Wave Eikonal Traveltime (WET) inversion. For ... -
Tomographic inversion of synthetic refraction seismic data. Quality of inversion using various off-end shots, fracture zones depth, fracture zone velocity, soil thickness and hidden layer thickness
Rønning, Jan Steinar; Tassis, Georgios; Wisén, Roger; Toresson, Björn (NGU-Rapport (2020.044), Report, 2021)NGU has studied tomographic inversion of refraction seismic data using the Rayfract software for years. In the present work, the quality of location and characterisation of fracture zones in bedrock as well as the quality ...