The crustal structure along the POLAR Profile from seismic refraction investigations

Luosto, U.; Flueh, Ernst R.; Lund, C.‐E.

doi:10.1016/0040-1951(89)90356-9

Cited by 86 publications

(38 citation statements)

References 6 publications

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“…12b). This observation is consistent with similar findings from the POLAR profile, approximately 50 km north-west of line 6 (Luosto et al, 1989;Walther and Flüh, 1993;Fig. 1b).…”

Section: Crustal Velocity Structuresupporting

confidence: 93%

“…10) together with available observations from the surrounding regions (Aleshin et al, 2006;Båth, 1984;FENNIA Working Group, 1998;Grad and Luosto, 1987;Komminaho and Yliniemi, 1992;Luosto et al, 1989Luosto et al, , 1990Luosto et al, , 1995Olsson, 2007;Erinchek et al, 2006;Korja et al, 2001;Korsman et al, 1999;Luosto, 1991) were used to construct an updated Moho depth map (Fig. 12a).…”

Section: Modelling Of P and S Waves And Moho Depthmentioning

confidence: 99%

“…The Archean bedrock has been surveyed along FINLAP (Luosto et al, 1983) and POLAR (Luosto et al, 1989;Walther and Flüh, 1993;Janik et al, 2009) refraction seismic profiles in northern Finland as well as along Kem-Uchta (Berzin et al, 2002), Kem-Tulos, and Pechenga-Kostomuksha ) refraction profiles in north-western Russia (Fig. 1b).…”

Section: Previous Active Seismic Surveysmentioning

confidence: 99%

See 2 more Smart Citations

Crustal seismic structure and depth distribution of earthquakes in the Archean Kuusamo region, Fennoscandian Shield

Uski¹,

Tiira²,

Grad³

et al. 2012

Journal of Geodynamics

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“…12b). This observation is consistent with similar findings from the POLAR profile, approximately 50 km north-west of line 6 (Luosto et al, 1989;Walther and Flüh, 1993;Fig. 1b).…”

Section: Crustal Velocity Structuresupporting

confidence: 93%

Section: Modelling Of P and S Waves And Moho Depthmentioning

confidence: 99%

Section: Previous Active Seismic Surveysmentioning

confidence: 99%

See 1 more Smart Citation

Crustal seismic structure and depth distribution of earthquakes in the Archean Kuusamo region, Fennoscandian Shield

Uski¹,

Tiira²,

Grad³

et al. 2012

Journal of Geodynamics

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“…P-receiver functions were computed from multiple teleseismic events recorded at each station and H-k stacking (Zhu & Kanamori 2000) and waveform modelling is used in order to extract 2-D crustal models beneath each station. These results are compared with previous models for crustal thickness beneath the region (Luosto et al 1984;Grad & Luosto 1987;Luosto et al 1989Luosto et al , 1990Luosto 1997;Grad et al 2009). This study results in a new Poisson's ratio map and a Moho map which is an improvement on the large scale, reference models of the European crust produced by Kelly et al (2007), EuCRUST-07 of Tesauro et al (2008) and EUNASeis of .…”

Section: Introductionmentioning

confidence: 87%

Crustal properties of the northern Scandinavian mountains and Fennoscandian shield from analysis of teleseismic receiver functions

Mansour

England

Fishwick

et al. 2018

Geophysical Journal International

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S U M M A R YThe presence of high mountains along passive margins is not unusual, as shown by their presence in several regions (Scandinavia, Greenland, East US, SW Africa, Brazil, West India and SE Australia). However, the origin of this topography is not well understood. The mountain range between the Scandinavian passive margin and the Fennoscandian shield is a good example. A simple Airy isostatic model would predict a compensating root beneath the mountains but existing seismic measurements of variations in crustal thickness do not provide evidence of a root of sufficient size to produce the necessary compensation. In order to better constrain the physical properties of the crust in northern Scandinavia, two broad-band seismic networks were deployed between 2007 and 2009 and between 2013 and 2014. A new map of crustal thickness has been produced from P-receiver function analysis of teleseismic data recorded at 31 seismic stations. The map shows an increase in crustal thickness from the Atlantic coast (38.7 ± 1.8 km) to the Gulf of Bothnia (43.5 ± 2.4 km). This gradient in thickness demonstrates that the Moho topography does not mirror the variation in surface topography in this region. Thus, classical Airy isostatic models cannot explain how the surface topography is supported. New maps showing variation in Poisson's ratio and Moho sharpness together with forward and inverse modelling provide new information about the contrasting properties of the Fennoscandian shield and crust reworked by the Caledonian orogeny. A sharp Moho transition (R > 1) and low value of V s (3.5 ± 0.2 km s −1 ) are observed beneath the orogen. The shield is characterized by a gradual transition across the Moho (R < 1) and V s of 3.8 ± 0.1 km s −1 which is more typical of average continental crust. These observations are explained by a Fennoscandian shield underplated with a thick layer of high velocity, high density material. It is proposed that this layer has been removed or reworked beneath the orogen.

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“…2; POLAR, SVEKA81, BALTIC, FIRE1, FIRE4) or revealing the internal architecture of the Archean (EU1, 4B, KostomukshaPechenga) or Paleoproterozoic (EGT/FENNOLORA, FINLAP7) (LUOSTO et al 1990;GUGGISBERG et al 1991;SHAROV 1993;MINTS et al 2004a;MINTS et al 2004b;GRAD and LUOSTO 1987;LUOSTO et al 1989;KUKKONEN et al 2006;PATISON et al 2006;JANIK et al 2009). Nevertheless, neither the lateral change along the strike of the terranes nor the more gradual NW-SE change from Archean to Paleoproterozoic dominated areas, is well understood.…”

Section: Introductionmentioning

confidence: 99%

Crustal Architecture of the Inverted Central Lapland Rift Along the HUKKA 2007 Profile

Tiira

Janik

Kozlovskaya

et al. 2013

Pure Appl. Geophys.

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Abstract-We have studied the lateral velocity variations along a partly buried inverted paleo-rift in Central Lapland, Northern Europe with a 2D wide-angle reflection and refraction experiment, HUKKA 2007. The experiment was designed to use seven chemical explosions from commercial and military sites as sources of seismic energy. The shots were recorded by 102 stations with an average spacing of 3.45 km. Two-dimensional crustal models of variations in P-wave velocity and Vp/Vs-ratio were calculated using the ray tracing forward modeling technique. The HUKKA 2007 experiment comprises a 455 km long profile that runs NNW-SSE parallel to the Kittilä Shear Zone, a major deformation zone hosting gold deposits in the area. The profile crosses Paleoproterozoic and reactivated Archean terranes of Central Lapland. The velocity model shows a significant difference in crustal velocity structure between the northern (distances 0-120 km) and southern parts of the profile. The difference in P-wave velocities and Vp/Vs ratio can be followed through the whole crust down to the Moho boundary indicating major tectonic boundaries. Upper crustal velocities seem to vary with the terranes/compositional differences mapped at the surface. The lower layer of the upper crust displays velocities of 6.0-6.1 km/s. Both Paleoproterozoic and Archean terranes are associated with high velocity bodies (6.30-6.35 km/s) at 100 and 200-350 km distances. The Central Lapland greenstone belt and Central Lapland Granitoid complex are associated with a 4 km-thick zone of unusually low velocities (\6.0 km/s) at distances between 120 and 220 km. We interpret the HUKKA 2007 profile to image an old, partly buried, inverted continental rift zone that has been closed and modified by younger tectonic events. It has structural features typical of rifts: inward dipping rift shoulders, undulating thickness of the middle crust, high velocity lower crust and a rather uniform crustal thickness of 48 km.

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The crustal structure along the POLAR Profile from seismic refraction investigations

Cited by 86 publications

References 6 publications

Crustal seismic structure and depth distribution of earthquakes in the Archean Kuusamo region, Fennoscandian Shield

Crustal seismic structure and depth distribution of earthquakes in the Archean Kuusamo region, Fennoscandian Shield

Crustal properties of the northern Scandinavian mountains and Fennoscandian shield from analysis of teleseismic receiver functions

Crustal Architecture of the Inverted Central Lapland Rift Along the HUKKA 2007 Profile

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