scholarly journals Faulting and Folding Signals in Seismic Data

Eos ◽  
2021 ◽  
Vol 102 ◽  
Author(s):  
Kate Wheeling

A novel numerical model simulates folding in Earth’s crust throughout the earthquake cycle.

2020 ◽  
Vol 221 (1) ◽  
pp. 651-664
Author(s):  
H Heydarizadeh Shali ◽  
D Sampietro ◽  
A Safari ◽  
M Capponi ◽  
A Bahroudi

SUMMARY The study of the discontinuity between crust and mantle beneath Iran is still an open issue in the geophysical community due to its various tectonic features created by the collision between the Iranian and Arabian Plate. For instance in regions such as Zagros, Alborz or Makran, despite the number of studies performed, both by exploiting gravity or seismic data, the depth of the Moho and also interior structure is still highly uncertain. This is due to the complexity of the crust and to the presence of large short wavelength signals in the Moho depth. GOCE observations are capable and useful products to describe the Earth’s crust structure either at the regional or global scale. Furthermore, it is plausible to retrieve important information regarding the structure of the Earth’s crust by combining the GOCE observations with seismic data and considering additional information. In the current study, we used as observation a grid of second radial derivative of the anomalous gravitational potential computed at an altitude of 221 km by means of the space-wise approach, to study the depth of the Moho. The observations have been reduced for the gravitational effects of topography, bathymetry and sediments. The residual gravity has been inverted accordingly to a simple two-layer model. In particular, this guarantees the uniqueness of the solution of the inverse problem which has been regularized by means of a collocation approach in the frequency domain. Although results of this study show a general good agreement with seismically derived depths with a root mean square deviation of 6 km, there are some discrepancies under the Alborz zone and also Oman sea with a root mean square deviation up 10 km for the former and an average difference of 3 km for the latter. Further comparisons with the natural feature of the study area, for instance, active faults, show that the resulting Moho features can be directly associated with geophysical and tectonic blocks.


2011 ◽  
Vol 66 (3) ◽  
pp. 213-219
Author(s):  
V. B. Piip ◽  
L. P. Tsydypova ◽  
N. V. Shalaeva ◽  
E. A. Teplyakova

Author(s):  
Romela Pashayan ◽  
Levon Harutyunyan ◽  
Kristina Tovmasyan

The geodynamics of the earth’s crust in the territory of Armenia is given according to seismic data, deformographic measurements, hydro geodynamic observations of the groundwater level, and geochemistry of mineral waters in the central part of the region. The map of the epicenters of earthquakes over the past three years includes stressed sections (concentration of earthquake epicenters) of the earth’s crust with increased activity geodynamic processes. Based on the results of the registration of deformations of two directions, the values of areal, volumetric, and vertical deformations are calculated. Variations in the water level in hydro geodynamic wells were obtained due to seismic events; the amplitudes of the variations depend on the magnitude of the earthquake, the distance from the epicenter, and the magnitude of the calculated deformation of the earth’s crust. The main components of the chemical composition of mineral waters (CL, HCO3, SO4, Mg), gas - CO2, and Ph in comparison with seismicity and other geodynamic processes of the earth’s crust.


1972 ◽  
Vol 9 (4) ◽  
pp. 339-352 ◽  
Author(s):  
Maurice K. Seguin

The author completely reviews previous geophysical work related to the nature and structure of the earth's crust in Fennoscandia. He explains the analytical procedure used for the seismic data and the method used to locate seismic events in Fennoscandia. Having described the method of analysis, the procedure for the calculation of the velocity of the seismic waves, and the location of seismic events which originate from Fennoscandia as well as the characteristics of the seismic waves registered, the author calculates the thickness of 3 layers which constitute the earth's crust at various localities in Fennoscandia and drafts a spatial distribution for the thickness of each of these layers. The first order variations, which agree with the relative thickness of the layers, indicate the presence of a generally east-west gradient. A general thinning of the crust was observed to the west in Fennoscandia. In view of the results obtained, the author draws conclusions relative to the tectonic activity and the global geodynamics in Fennoscandia.


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