caa a22 4500 606149023 CHVBK 20210128100532.0 cr unu---uuuuu 210128e20150101xx s 000 0 eng 10.1007/s00531-014-1061-2 doi (NATIONALLICENCE)springer-10.1007/s00531-014-1061-2 Stress, rheological structure and earthquakes in the POLAR profile in the northern Fennoscandian Shield [Elektronische Daten] [K. Moisio, P. Kaikkonen] We model stress fields and potential areas of deformation, use differences to analyse the possible variations in the modelling results and investigate the relations between the earthquakes and our modelling results in the POLAR profile in the northern Fennoscandian Shield. Calculated stress fields show rather uniform distribution, with significant deviations concentrated in rheologically weaker regions, mainly in the middle crust. Significant areas of deformation are also connected to these weaker regions, in the crust and also in the mantle. These regions control whether decoupled or coupled mechanical conditions exist. Further analysis shows that major differences between the stress fields calculated with dry and wet rheologies are found in the lower part of the middle crust extending from the Lapland Granulite Belt area towards the northeast. Similarly, differences between the models due to the varying heat production and the depth of the thermal lithosphere-asthenosphere boundary concentrate in rheologically weak crustal regions and in the mantle. These differences display importance of the rheological composition and thermal structure in rheological modelling. Our rheological model for reverse stress regime with typically used values of 0.35 for pore fluid factor and 0.75 for friction coefficient seems to result in too strong crust in order to explain satisfactorily the earthquakes focal depths in the POLAR profile. Most of the earthquakes can be explained by reverse stress regime if high pore pressure conditions exist. However, for the deepest events, it seems that also changes both in stress regime and in friction coefficients are needed. Rheologically, weak middle crust in the central and north-eastern parts of the POLAR could explain the absence of deep earthquakes in these parts of the profile. Springer-Verlag Berlin Heidelberg, 2014 Fennoscandian Shield nationallicence Lithosphere nationallicence Rheological strength nationallicence Stress modelling nationallicence Earthquakes nationallicence Moisio K. Geophysics, Department of Physics, University of Oulu, P.O. Box 3000, 90014, Oulu, Finland aut Kaikkonen P. Geophysics, Department of Physics, University of Oulu, P.O. Box 3000, 90014, Oulu, Finland aut International Journal of Earth Sciences Springer Berlin Heidelberg 104/1(2015-01-01), 221-239 1437-3254 104:1<221 2015 104 531 https://doi.org/10.1007/s00531-014-1061-2 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00531-014-1061-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Moisio K. Geophysics, Department of Physics, University of Oulu, P.O. Box 3000, 90014, Oulu, Finland aut NATIONALLICENCE 700 1- Kaikkonen P. Geophysics, Department of Physics, University of Oulu, P.O. Box 3000, 90014, Oulu, Finland aut NATIONALLICENCE 773 0- International Journal of Earth Sciences Springer Berlin Heidelberg 104/1(2015-01-01), 221-239 1437-3254 104:1<221 2015 104 531