ScanArray—A Broadband Seismological Experiment in the Baltic Shield

Abstract

The ScanArray international collaborative program acquired broadband seismological data at 192 locations in the Baltic Shield during the period between 2012 and 2017. The main objective of the program is to provide seismological constraints on the structure of the lithospheric crust and mantle as well as the sublithospheric upper mantle. The new information will be applied to studies of how the lithospheric and deep structure affect observed fast topographic change and geological-tectonic evolution of the region. The program also provides new information on local seismicity, focal mechanisms, and seismic noise. The recordings are generally of very high quality and are used for analysis by various seismological methods, including P- and S-wave receiver functions for the crust and upper mantle, surface wave and ambient noise inversion for seismic velocity, body-wave P- and S-wave tomography for upper mantle velocity structure using ray and finite frequency methods, and shear-wave splitting measurements for obtaining bulk anisotropy of the upper and lowermost mantle. Here, we provide a short overview of the data acquisition and initial analysis of the new data, together with an example of integrated seismological results obtained by the project group along a representative ∼1800-km-long profile across most of the tectonic provinces in the Baltic Shield between Denmark and the North Cape. The first models support a subdivision of the Paleoproterozoic Svecofennian province into three domains, where the highest topography of the Scandes mountain range in Norway along the Atlantic Coast has developed solely in the southern and northern domains, whereas the topography is more subdued in the central domain.

Highly heterogeneous upper-mantle structure in Fennoscandia from finite-frequency P-body-wave tomography

“…The ScanArray experiment (Thybo et al 2012(Thybo et al , 2021 is an extensive collaboration between the universities of Aarhus, Bergen, Copenhagen, Karlsruhe, Leicester, Oslo and Uppsala, Istanbul Technical University, GFZ Potsdam and NORSAR that focuses on the structure of the lithosphere and upper-mantle processes below Scandinavia. The experiment has acquired broad-band seismic data on a dense array of temporary seismometers for 4 yr.…”

The Radial Anisotropy of the Continental Lithosphere From Analysis of Love and Rayleigh Wave Phase Velocities in Fennoscandia

“…MAUPIN ET AL. The ScanArray data set is a collection of seismic data from Fennoscandia following the temporary deployment of stations from 2012 to 2017 (Thybo et al, 2021), which we supplement with stations from several permanent networks (Figure 1). We select only a subset of the ScanArray stations to ensure a regular coverage.…”

“…Other data were downloaded from the European Integrated Data Archive (EIDA). Seismic data from the following networks were used: ScanAr-rayCore 1G-2012 (Thybo et al, 2012); NEONOR2 2D-2013 (https://www.fdsn.org/networks/detail/2D_2013/); SCANLIPS3D ZR-2013 (England et al, 2015); Swedish National Seismic Network UP (SNSN, 1904); Finnish National Seismic Network HE (Institute of Seismology University of Helsinki, 1980); Northern Finland Seismic Network FN (https://geofon.gfz-potsdam.de/waveform/archive/network.php?ncode=FN); Danish National Seismic Network (https://geofon.gfz-potsdam.de/waveform/archive/network.php?ncode=DKDK), NORSAR (NO (NORSAR, 1971), Norwegian National Seismic Network NS (University of Bergen, 1982)), and Global Insightful reviews by Vadim Levin, an anonymous reviewer and the associate editor are greatly appreciated. VM acknowledges support from the Research Council of Norway through its Centers of Excellence funding scheme, Project number 223272.…”

A Generalized Strategy From S‐Wave Receiver Functions Reveals Distinct Lateral Variations of Lithospheric Thickness in Southeastern Tibet

“…SRF is the most widely used method for detecting the LAB because the Sp converted phase is remarkably sensitive to the vertical velocity gradient at the typical LAB depth. More importantly, even if the PRF has higher temporal and depth resolution in most cases, it has serious contamination by other phases across the LAB depth (Chen et al., 2009; Hansen et al., 2010; Hu et al., 2011; Levander & Miller, 2012; Liu, Klemperer, & Blanchette, 2021; Liu & Zhao, 2021; Thybo et al., 2021; Zhang et al., 2014). Coordinate system rotation and deconvolution are important steps for obtaining SRFs.…”

“…LAB depth (Chen et al, 2009;Hansen et al, 2010;Hu et al, 2011;Levander & Miller, 2012;Liu, Klemperer, & Blanchette, 2021;Liu & Zhao, 2021;Thybo et al, 2021;Zhang et al, 2014). Coordinate system rotation and deconvolution are important steps for obtaining SRFs.…”