POLENET/FI - a multidisciplinary geophysical experiment in northern Fennoscandia and Antarctica during IPY 2007-2008.

Leaders:
Prof. Markku Poutanen (Finnish Geodetic Institute), Doc.Elena Kozlovskaya (Sodankylä Geophysical Observatory of the University of Oulu)

Participating organisations:
POLENET Consortium Member Institutes; Sodankylä Geophysical Observatory of the University of Oulu, Institute of Seismology of the University of Helsinki (FINLAND); Geophysical Institute of Academy of Sciences, Prague (CZECH REPUBLIC); University of Grenoble, University of Strasbourg (FRANCE); Insitute of Geodesy and Geophysics Vienna University of Technology (AUSTRIA), Institute of Geophysics ETH Zuerich (SWITZERLAND); GeoForschungsZentrum Potsdam (GERMANY); NORSAR (NORWAY )

POLENET/GEOD: Collocated seismic and geodetic measurements
in Finland and Antarctica

Existing GPS, superconducting gravimeter and seismograph stations and satellite observations in Finland and Anctarctica can be used to organize long-term collocated measurements aiming at studying of the inner core within the frame of the POLENET scientific program. In addition, such measurements can be used to study glacial rebound in the Fennoscandian Shield and Antarctica, to improve our current understanding of displacements and stresses for stable cratonic regions and mid-continent deformations and investigate interplate earthquake mechanisms. Since the GPS, gravity measurements and seismic instrumentation share infrastructure, the cost of multidisciplinary observation network is lower than organisation of two separate networks.

Fennoscandia: LAPNET seismic field deployment

The POLENET/LAPNET is a sub-project of the POLENET consortium related to POLENET seismic and geodetic studies in the Arctic regions. POLENET/LAPNET activities will be carried out on the territory of northern Fennoscandia (Finland and Norway). The project was developed on the base of Expression of Intent for IPY No. 34 that received approval from the IPY Joint Committee and recommendation to join the POLENET project cluster (http://www.ipy.org/development/eoi/details.php?id=34). The main target of the POLENET/LAPNET project is to carry out a temporary broadband seismic array research in the area of northern Finland and Norway. The array will consist of 30-35 temporary stations, 3 permanent broadband stations (OUL, SGF and MSF) of Oulu University and two permanent stations (KEV and KIF) operated by the Institute of Seismology of Helsinki University. The array will register teleseismic, regional and local events during 2007-2009.

The research aims to obtain a 3D seismic model of the crust and upper mantle down to 670 km (P- and S-wave velocity models, position of major boundaries in the crust and upper mantle and estimates of seismic anisotropy strength and orientation) in northern Fennoscandian Shield, in particular, beneath the Archaean domain of the Fennoscandian Shield. The model will be merged to the seismic model of the previous SVEKALAPKO array research in order to obtain a 3-D model of the crust and upper mantle beneath Finland. The 3-D model can be used to define spatial distribution and depth of the Archaean lithosphere below Finland for the purpose of diamond prospecting. The 3-D model of the crust and upper mantle will be also used to improve registration and location of local earthquakes and understanding of mechanisms of local seismicity in northern Fennoscandia.

The study will also contribute to the POLENET multidisciplinary research in northern Fennoscandia by collecting waveforms of seismic phases travelling through the inner core. The waveform data will be compiled into a database that will be available to world geophysical community via GEOFON Data Center (GeoForschungZentrum Potsdam) and interpreted by different techniques.