Moho depth variation in the Baltic Shield from analysis of converted waves

Olsson, Sverker; Roberts, Roland; Böðvarsson, Reynir

doi:10.1080/11035890801303113

Cited by 4 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In more realistic cases, however, the methodology has significant problems, showing multiple local maxima (e.g. Eaton et al 2006;Olsson et al 2008). In addition, the results depend on the validity of the chosen range of H and k values since this choice influences the resulting global maximum: a maximum outside of an overly restrictive grid will be excluded while a very liberal grid may include a number of non-physical maxima.…”

Section: Discussion a N D C O N C L U S I O N Smentioning

confidence: 99%

Combining controlled-source seismology and receiver function information to derive 3-D Moho topography for Italy

Spada¹,

Bianchi

Kissling

et al. 2013

Geophysical Journal International

143

204

View full text Add to dashboard Cite

The accurate definition of 3-D crustal structures and, in primis, the Moho depth, are the most important requirement for seismological, geophysical and geodynamic modelling in complex tectonic regions. In such areas, like the Mediterranean region, various active and passive seismic experiments are performed, locally reveal information on Moho depth, average and gradient crustal V p velocity and average V p /V s velocity ratios. Until now, the most reliable information on crustal structures stems from controlled-source seismology experiments. In most parts of the Alpine region, a relatively large number of controlled-source seismology information are available though the overall coverage in the central Mediterranean area is still sparse due to high costs of such experiments. Thus, results from other seismic methodologies, such as local earthquake tomography, receiver functions and ambient noise tomography can be used to complement the controlled-source seismology information to increase coverage and thus the quality of 3-D crustal models. In this paper, we introduce a methodology to directly combine controlled-source seismology and receiver functions information relying on the strengths of each method and in relation to quantitative uncertainty estimates for all data to derive a well resolved Moho map for Italy. To obtain a homogeneous elaboration of controlledsource seismology and receiver functions results, we introduce a new classification/weighting scheme based on uncertainty assessment for receiver functions data. In order to tune the receiver functions information quality, we compare local receiver functions Moho depths and uncertainties with a recently derived well-resolved local earthquake tomography-derived Moho map and with controlled-source seismology information. We find an excellent correlation in the Moho information obtained by these three methodologies in Italy. In the final step, we interpolate the controlled-source seismology and receiver functions information to derive the map of Moho topography in Italy and surrounding regions. Our results show high-frequency undulation in the Moho topography of three different Moho interfaces, the European, the Adriatic-Ionian, and the Liguria-Corsica-Sardinia-Tyrrhenia, reflecting the complexity of geodynamical evolution.

show abstract

Section: Discussion a N D C O N C L U S I O N Smentioning

confidence: 99%

Combining controlled-source seismology and receiver function information to derive 3-D Moho topography for Italy

Spada¹,

Bianchi

Kissling

et al. 2013

Geophysical Journal International

143

204

View full text Add to dashboard Cite

show abstract

“…Crustal velocity and thickness are mainly determined by seismic refraction experiments and by analyses of receiver functions (EUGENO-S Working Group 1988; Iwasaki et al 1994;Svenningsen et al 2007;Olsson et al 2008;Sandrin & Thybo 2008;Stratford et al 2009;Stratford & Thybo 2011;. For a recent compilation and analysis, see Artemieva & Thybo (2013).…”

Section: Previous Studiesmentioning

confidence: 99%

Upper-mantleP- andS-wave velocities across the Northern Tornquist Zone from traveltime tomography

et al. 2015

View full text Add to dashboard Cite

S U M M A R YThis study presents P-and S-wave velocity variations for the upper mantle in southern Scandinavia and northern Germany based on teleseismic traveltime tomography. Tectonically, this region includes the entire northern part of the prominent Tornquist Zone which follows along the transition from old Precambrian shield units to the east to younger Phanerozoic deep sedimentary basins to the southwest. We combine data from several separate temporary arrays/profiles (276 stations) deployed over a period of about 15 yr and permanent networks (31 stations) covering the areas of Denmark, northern Germany, southern Sweden and southern Norway. By performing an integrated P-and S-traveltime analysis, we obtain the first high-resolution combined 3-D V P and V S models, including variations in the V P /V S ratio, for the whole of this region of study. Relative station mean traveltime residuals vary within ±1 s for P wave and ±2 s for S wave, with early arrivals in shield areas of southern Sweden and later arrivals in the Danish and North German Basins, as well as in most of southern Norway. In good accordance with previous, mainly P-velocity models, a marked upper-mantle velocity boundary (UMVB) is accurately delineated between shield areas (with high seismic mantle velocity) and basins (with lower velocity). It continues northwards into southern Norway near the Oslo Graben area and further north across the Southern Scandes Mountains. This main boundary, extending to a depth of at least 300 km, is even more pronounced in our new S-velocity model, with velocity contrasts of up to ±2-3 per cent. It is also clearly reflected in the V P /V S ratio. Differences in this ratio of up to about ±2 per cent are observed across the boundary, with generally low values in shield areas to the east and relatively higher values in basin areas to the southwest and in most of southern Norway. Differences in the V P /V S ratio are believed to be a rather robust indicator of upper-mantle compositional differences. For the depth interval of about 100-300 km, thick, depleted, relatively cold shield lithosphere is indicated in southern Sweden, contrasting with more fertile, warm mantle asthenosphere beneath most of the basins in Denmark and northern Germany. Both compositional and temperature differences seem to play a significant role in explaining the UMVB between southern Norway and southern Sweden. In addition to the main regional upper-mantle velocity contrasts, a number of more local anomaly features are also outlined and discussed.

show abstract

A New Seismic Data Set on the Depth of the Moho in the Alps

Bianchi

Behm

Rumpfhuber

et al. 2014

Pure Appl. Geophys.

View full text Add to dashboard Cite

We present the results from receiver function analysis applied to a comprehensive data set in the Eastern Alps. Teleseismic events were recorded at 70 stations with an average deployment of 1 year. The investigated area includes the eastern part of the Eastern Alps and their transition to the Bohemian Massif, the Pannonian domain, and the Southern Alps. The crustal structure at each station is examined with the Zhu-Kanamori (ZK) method, which yields well-resolved interface depths in laterally homogeneous media with limited layering. The application of the ZK technique is challenged because of the complex tectonic setting; therefore, we include additional constraints from recent active-source seismic studies. In particular, the well-known crustal P-wave velocity and, where available, the V p /V s ratio are kept fixed, thus reducing the ambiguity in determining Moho depths. Individual depth values vary strongly between adjacent stations, showing that the employment of the ZK technique in tectonically complex settings is limited. We therefore avoid interpreting the results in detail, but rather compare them to existing crustal models of the Eastern Alps. We regard this receiver function study in the easternmost part of the Alps as a documentation of a data set that has potential to be exploited in the future.

show abstract

Moho depth variation in the Baltic Shield from analysis of converted waves

Cited by 4 publications

References 0 publications

Combining controlled-source seismology and receiver function information to derive 3-D Moho topography for Italy

Combining controlled-source seismology and receiver function information to derive 3-D Moho topography for Italy

Upper-mantleP- andS-wave velocities across the Northern Tornquist Zone from traveltime tomography

A New Seismic Data Set on the Depth of the Moho in the Alps

Contact Info

Product

Resources

About