GNGTS 2014 - Atti del 33° Convegno Nazionale

GNGTS 2014 S essione 3.1 119 improve the coverage necessary at a relative low acquisition cost. New contributions for optimizing the acquisition pattern will come from the conclusion of the data processing that presently is analyzing the recorded data amplitude spectra for the different sources and geophones and the overall data quality. Also from the very first results of the tomographic analysis on the single L100 line, the possibility of jointly invert both reflected and refracted arrivals enables to improve the ray coverage, and, therefore, the inversion reliability, while exploiting at the best the seismic experiment information. In the next months, both velocities and interface depth and shape will be refined by jointly inverting the other two lines and the offline shots, providing a more extended and detailed model of the velocities below and around Innerhytta pingo. Acknowledgements. The project IMPERVIA is a PNRA project (PdR 2010/A2.14 “IMPERVIA”). We are grateful to Hanne Christiansen for the full support given to the project and the useful discussions before and during the field work, we are also indebted with Sara Mollie Cohen and to Mark Mulrooney of the UNIS Geoscience department and to the UNIS Logistic department staff for the assistance, patience and support for the whole field work duration. We thank, furthermore, all the UNIS and Norwegian Polar Institute personnel for the kind help that gave to us. References Boaga J., Vignoli G. and Cassiani G.; 2011: Shear wave profiles from surface wave inversion: the impact of uncertainty on seismic site response analysis , J. Geophys. Eng. 8 162-174, doi:10.1088/1742-2132/8/2/004. Böhm G., Rossi G. and Vesnaver A.; 1999: Minimum time ray-tracing for 3-D irregular grids. Journal of Seismic Exploration 8, 117–131. Braathen, A., Bælum, K., Christiansen, H.H., Dahl, T., Eiken, O., Elvebakk, H., Hansen, F., Hanssen, T.H., Jochmann, M., Johansen, T.A., Johnsen, H., Larsen, L., Lie, T., Mertes, J., Mørk, A., Mørk, M.B., Nemec, W., Olaussen, S., Oye, V., Rød, K., Titlestad, G.O., Tveranger, J. and Vagle, K.; 2012: The Longyearbyen CO2 Lab of Svalbard, Norway—initial assessment of the geological conditions for CO2 sequestration . Norwegian Journal of Geology, 92, 353–376. Christiansen H.H., Etzelmüller B., Isaksen K., Juliussen H., Farbrot H., Humlum O., Johansson M., Ingeman-Nielsen T., Kristensen L., Hjort J., Holmlund P., Sannel A.B.K., Sigsgaard C., Åkerman H.J., Foged N., Blikra L.H., Pernosky M.A., Ødegård R.; 2010: The thermal state of permafrost in the Nordic area during IPY 2007–2009 . Permafrost and Periglacial Processes 21, 156–181. Juliussen H., Christiansen H.H., Strand G.S., Iversen S., Midttømme K., Rønning J.S.; 2010: NORPERM, the Norwegian Permafrost Database – a TSP NORWAY IPY legacy . Earth System Science Data Discussions 3, 27– 54. Lecomte I., Polom U., Sauvin G., Ruud B.O. Shear-wave Reflection-seismic Pilot Study at the UNIS CO2 Lab site, Longyearbyen, Svalbard, EAGE 72 meeting Extended abstracts, DOI: 10.3997/2214-4609.20141243. Major H., Haremo P., Dallmann W.K. and Andresen A.; 2000: Geological Map of Svalbard 1 : 100,000 Sheet C9G Adventdalen (revised after Major 1964). Temakart No. 31. Norwegian Polar Institute, Tromsø. Oye V., Braathen A., Polom U.; 2013: Preparing for CO2 storage at the Longyearbyen CO2 Lab: microseismic monitoring of injection tests , First Break, 31, Ross, N., BrabhamP.J., Harris C. and Christiansen, H.H.; 2007: Internal Structure of Open SystemPingos, Adventdalen, Svalbard: The Use of Resistivity Tomography to Assess Ground-Ice Conditions . Journal of Environmental & Engineering Geoscience, 12, 113-126. Ross N., Harris C., Christiansen H.H and Brabham P.; 2005: Ground penetrating radar investigations of open system pingos, Adventalen, Svalbard . Norsk Geografisk Tidsskrift - Norwegian Journal of Geography, 59, 129-138. Rossi G., Gei D., Böhm G., Madrussani G. and Carcione J.M.; 2007: Attenuation tomography: an application to gas- hydrate and free-gas detection , Geophys. Prosp., 55, 655 – 669. Rossi, G., Corubolo P., Böhm G., Ceraggioli E., Dell’Aversana P., Morandi S., Poletto F. and Vesnaver A.; 2001: Joint 3-D inversion of SWD and surface seismic data , First Break, 19, 453-459. van der SluisA. and van der Vorst H.A.; 1987: Numerical solution of large sparse linear algebraic systems arising from tomographic problems . In: Seismic Tomography (ed. G. Nolet), pp. 49–83. Reidel Publishing Co., Dordrecht. Vesnaver A., Böhm G., Madrussani G., Petersen S. and Rossi G.; 1999: Tomographic imaging by reflected and refracted arrivals at the North Sea . Geophysics 64, 1852–1862. Vesnaver, A., Böhm G., Madrussani G., Rossi G. and Granser H.; 2000: Depth imaging and velocity calibration by 3D adaptive tomography , First Break, 18, 303-312. Zhu, T., Yan Y., Downton J.; 2011: Near-surface velocity model building and statics in permafrost regions , 2011 CSEG Convention.