Variations in crustal and lithospheric structure across the Eastern Indian Shield from passive seismic source imaging: Implications to changes in the tectonic regimes and crustal accretion through the Precambrian

2021 ◽  
Vol 360 ◽  
pp. 106207
Author(s):  
Prantik Mandal ◽  
Prakash Kumar ◽  
B. Sreenivas ◽  
E.V.S.S.K. Babu ◽  
Y.J. Bhaskar Rao
Keyword(s):  
Seismic Source ◽  
Lithospheric Structure ◽  
Crustal Accretion ◽  
Indian Shield ◽  
Source Imaging ◽  
Passive Seismic

Lithospheric structure beneath the Central Africa Orogenic Belt in Cameroon from the analysis of satellite gravity and passive seismic data

2018 ◽  
Vol 745 ◽  
pp. 326-337 ◽  
Author(s):  
Jeannot F. Goussi Ngalamo ◽  
Mohamed Sobh ◽  
Dieudonne Bisso ◽  
Mohamed G. Abdelsalam ◽  
Estella Atekwana ◽  
...  
Keyword(s):  
Seismic Data ◽  
Central Africa ◽  
Orogenic Belt ◽  
Lithospheric Structure ◽  
Satellite Gravity ◽  
Passive Seismic

Source location with cross-coherence migration

Geophysics ◽  
2020 ◽  
Vol 85 (4) ◽  
pp. KS127-KS138 ◽  
Author(s):  
Yujin Liu ◽  
Yue Ma ◽  
Yi Luo
Keyword(s):  
Field Data ◽  
Random Noise ◽  
Synthetic Data ◽  
Seismic Energy ◽  
Seismic Source ◽  
Spectral Amplitude ◽  
Multiple Sources ◽  
Passive Seismic ◽  
Similar Images ◽  
Resolution Property

Locating microseismic source positions using seismic energy emitted from hydraulic fracturing is essential for choosing optimal fracking parameters and maximizing the fracturing effects in hydrocarbon exploitation. Interferometric crosscorrelation migration (ICCM) and zero-lag autocorrelation of time-reversal imaging (ATRI) are two important passive seismic source locating approaches that are proposed independently and seem to be substantially different. We have proven that these two methods are theoretically identical and produce very similar images. Moreover, we have developed cross-coherence that uses normalization by the spectral amplitude of each of the traces, rather than crosscorrelation or deconvolution, to improve the ICCM and ATRI methods. The adopted method enhances the spatial resolution of the source images and is particularly effective in the presence of highly variable and strong additive random noise. Synthetic and field data tests verify the equivalence of the conventional ICCM and ATRI and the equivalence of their improved versions. Compared with crosscorrelation- and deconvolution-based source locating methods, our approach shows a high-resolution property and antinoise capability in numerical tests using synthetic data with single and multiple sources, as well as field data.

scholarly journals Humming Trains in Seismology: An Opportune Source for Probing the Shallow Crust

2021 ◽  
Author(s):  
Laura Pinzon-Rincon ◽  
François Lavoué ◽  
Aurélien Mordret ◽  
Pierre Boué ◽  
Florent Brenguier ◽  
...  
Keyword(s):  
Seismic Waves ◽  
Mineral Exploration ◽  
Low Cost ◽  
Complex Structure ◽  
Volcanic Eruptions ◽  
Seismic Source ◽  
Body Waves ◽  
Energy Output ◽  
Passive Seismic ◽  
Shallow Crust

Abstract Seismologists are eagerly seeking new and preferably low-cost ways to map and track changes in the complex structure of the top few kilometers of the crust. By understanding it better, they can build on what is known regarding important, practical issues. These include telling us whether imminent earthquakes and volcanic eruptions are generating telltale underground signs of hazard, about mitigation of induced seismicity such as from deep injection of wastewater, how the Earth and its atmosphere couple, and where accessible natural resources are. Passive seismic imaging usually relies on blind correlations within extended recordings of Earth’s ceaseless “hum” or coda of well-mixed, small vibrations. In this article, we propose a complementary approach. It is seismic interferometry using opportune sources—specifically ones not stationary in time and moving in a well-understood configuration. Its interpretation relies on an accurate understanding of how these sources radiate seismic waves, precise timing, careful placement of pairs of listening stations, and seismic phase differentiation (surface and body waves). Massive freight trains were only recently recognized as such a persistent, powerful cultural (human activity-caused) seismic source. One train passage may generate a tremor with an energy output of a magnitude 1 earthquake and be detectable for up to 100 km from the track. We discuss the source mechanisms of train tremors and review the basic theory on sources. Finally, we present case studies of body- and surface-wave retrieval as an aid to mineral exploration in Canada and to monitoring of a southern California fault zone. We believe noise recovery from this new signal source, together with dense data acquisition technologies such as nodes or distributed acoustic sensing, will deeply transform our ability to monitor activity in the shallow crust at sharpened resolution in time and space.

Locating flowing conduits in Karst using passive seismic deployments

2021 ◽  
Author(s):  
Haleh Karbala Ali ◽  
Christopher J. Bean ◽  
Caoimhe Hickey ◽  
Billy o'Keeffe
Keyword(s):  
Field Experiments ◽  
Synthetic Data ◽  
Seismic Source ◽  
Seismic Survey ◽  
Complex Structures ◽  
Passive Seismic ◽  
Complex Picture ◽  
County Roscommon ◽  
Seismic Amplitudes ◽  
Broad Understanding

<p>Karst is an important landscape in many locations incorporating many subterranean waterflow passages in the form of caves, conduits, and fractures. Although challenging, some karst structures can be imaged by active geophysical techniques however they generally cannot facilitate differentiation between flowing and non-flowing waterways. In this study, we aim to locate flowing conduits by passively capturing flow-induced seismic signals.</p><p>To gain a broad understanding of seismic source versus path effect in these complex structures and to help us design bespoke field experiments, we commence our study by undertaking 3D numerical simulation (using SPECFEM3D) for different cases of shallow and deep conduits. These choices are informed by known conduit geometries in Ireland (they have been dived). Spectral resonance, synthetic heat maps, and amplitude-based locations of synthetic data reveal interesting information regarding the conduit response.</p><p>Based on the results of these simulations, we designed the layout of a passive field experiment on karst on Pollnagran cave in County Roscommon, Ireland using 1Hz seismometers and 5 Hz Geophones. The karst deployment is also complemented by smaller experiments on surface rivers in order to help better understand observed signals. We also undertake an active hammer seismic survey at the site in order the build a model for future site-specific numerical simulations.</p><p>Consistent with numerical experiments, clear discrete frequencies associated with water flow are observed in the field data. A complex picture is emerging where the largest dived caves are not necessarily the flow structures with the largest seismic amplitudes.</p>

Comparison and generalization of correlation-based seismic-source imaging methods

2017 ◽  
Author(s):  
Lei Li ◽  
Ivan Abakumov ◽  
Hao Chen ◽  
Xiuming Wang ◽  
Dirk Gajewski
Keyword(s):  
Seismic Source ◽  
Source Imaging ◽  
Imaging Methods

scholarly journals Passive seismic source localization via common-reflection-surface attributes

2016 ◽  
Vol 60 (3) ◽  
pp. 531-546 ◽  
Author(s):  
Benjamin Schwarz ◽  
Alexander Bauer ◽  
Dirk Gajewski
Keyword(s):  
Source Localization ◽  
Seismic Source ◽  
Passive Seismic ◽  
Common Reflection Surface

scholarly journals Passive seismic recording of cryoseisms in Adventdalen, Svalbard

2021 ◽  
Vol 15 (1) ◽  
pp. 283-302
Author(s):  
Rowan Romeyn ◽  
Alfred Hanssen ◽  
Bent Ole Ruud ◽  
Helene Meling Stemland ◽  
Tor Arne Johansen
Keyword(s):  
Surface Wave ◽  
Wave Energy ◽  
Spatial Clustering ◽  
Thick Layer ◽  
Seismic Source ◽  
Seismic Monitoring ◽  
Theoretical Modelling ◽  
Seismic Events ◽  
Dispersion Pattern ◽  
Passive Seismic

Abstract. A series of transient seismic events were discovered in passive seismic recordings from 2-D geophone arrays deployed at a frost polygon site in Adventdalen, Svalbard. These events contain a high proportion of surface wave energy and produce high-quality dispersion images using an apparent offset re-sorting and inter-trace delay minimisation technique to locate the seismic source, followed by cross-correlation beamforming dispersion imaging. The dispersion images are highly analogous to surface wave studies of pavements and display a complex multimodal dispersion pattern. Supported by theoretical modelling based on a highly simplified arrangement of horizontal layers, we infer that a ∼3.5–4.5 m thick, stiff, high-velocity layer overlies a ∼30 m thick layer that is significantly softer and slower at our study site. Based on previous studies we link the upper layer with syngenetic ground ice formed in aeolian sediments, while the underlying layer is linked to epigenetic permafrost in marine-deltaic sediments containing unfrozen saline pore water. Comparing events from spring and autumn indicates that temporal variation can be resolved via passive seismic monitoring. The transient seismic events that we record occur during periods of rapidly changing air temperature. This correlation, along with the spatial clustering along the elevated river terrace in a known frost polygon, ice-wedge area and the high proportion of surface wave energy, constitutes the primary evidence for us to interpret these events as frost quakes, a class of cryoseism. In this study we have proved the concept of passive seismic monitoring of permafrost in Adventdalen, Svalbard.

A Compact Program for 3D Passive Seismic Source-Location Imaging

2021 ◽  
Author(s):  
Yangkang Chen ◽  
Omar M. Saad ◽  
Min Bai ◽  
Xingye Liu ◽  
Sergey Fomel
Keyword(s):  
Open Source ◽  
Seismic Source ◽  
Velocity Model ◽  
Source Location ◽  
Imaging Method ◽  
Python Script ◽  
Passive Seismic ◽  
Synthetic Test ◽  
Microseismic Source Location ◽  
C Program

Abstract Microseismic source-location imaging is important for inferring the dynamic status of reservoirs during hydraulic fracturing. The accuracy and resolution of the located microseismic sources are closely related to the imaging technique. We present an open-source program for high-fidelity and high-resolution 3D microseismic source-location imaging. The presented code is compact in the sense that all required subroutines are included in one single C program, based on which seismic wavefields can be propagated either forward during a synthetic test or backward during a real time-reversal imaging process. The compact C program is accompanied by a Python script known as the SConstruct file in the Madagascar open-source platform to compile and run the C program. The velocity model and recorded microseismic data can be input using the Python script. This compact program is useful for educational purposes and for future algorithm development. We introduce the basics of the imaging method used in the presented package and present one representative synthetic example and a field data example. The results show that the presented program can be reliably used to locate source locations using a passive seismic dataset.

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