The cross-dip correction as a tool to improve imaging of crooked-line seismic data: a case study from the post-glacial Burträsk fault, Sweden
Understanding the development of post-glacial faults and their associated seismic activity is crucial for risk assessment in Scandinavia. However, imaging these features and their geological environment is complicated due to special challenges of their hardrock setting, such as weak impedance contra...
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ftdoajarticles:oai:doaj.org/article:01b2cb012cea414bb07e65f0c383aea8 2023-05-15T17:45:06+02:00 The cross-dip correction as a tool to improve imaging of crooked-line seismic data: a case study from the post-glacial Burträsk fault, Sweden R. A. Beckel C. Juhlin 2019-04-01T00:00:00Z https://doi.org/10.5194/se-10-581-2019 https://doaj.org/article/01b2cb012cea414bb07e65f0c383aea8 EN eng Copernicus Publications https://www.solid-earth.net/10/581/2019/se-10-581-2019.pdf https://doaj.org/toc/1869-9510 https://doaj.org/toc/1869-9529 doi:10.5194/se-10-581-2019 1869-9510 1869-9529 https://doaj.org/article/01b2cb012cea414bb07e65f0c383aea8 Solid Earth, Vol 10, Pp 581-598 (2019) Geology QE1-996.5 Stratigraphy QE640-699 article 2019 ftdoajarticles https://doi.org/10.5194/se-10-581-2019 2022-12-31T01:25:58Z Understanding the development of post-glacial faults and their associated seismic activity is crucial for risk assessment in Scandinavia. However, imaging these features and their geological environment is complicated due to special challenges of their hardrock setting, such as weak impedance contrasts, often high noise levels and crooked acquisition lines. A crooked-line geometry can cause time shifts that seriously de-focus and deform reflections containing a cross-dip component. Advanced processing methods like swath 3-D processing and 3-D pre-stack migration can, in principle, handle the crooked-line geometry but may fail when the noise level is too high. For these cases, the effects of reflector cross-dip can be compensated for by introducing a linear correction term into the standard processing flow. However, existing implementations of the cross-dip correction rely on a slant stack approach which can, for some geometries, lead to a duplication of reflections. Here, we present a module for the cross-dip correction that avoids the reflection duplication problem by shifting the reflections prior to stacking. Based on tests with synthetic data, we developed an iterative processing scheme where a sequence consisting of cross-dip correction, velocity analysis and dip-moveout (DMO) correction is repeated until the stacked image converges. Using our new module to reprocess a reflection seismic profile over the post-glacial Burträsk fault in northern Sweden increased the image quality significantly. Strike and dip information extracted from the cross-dip analysis helped to interpret a set of southeast-dipping reflections as shear zones belonging to the regional-scale Burträsk Shear Zone (BSZ), implying that the BSZ itself is not a vertical but a southeast-dipping feature. Our results demonstrate that the cross-dip correction is a highly useful alternative to more sophisticated processing methods for noisy datasets. This highlights the often underestimated potential of rather simple but noise-tolerant methods in ... Article in Journal/Newspaper Northern Sweden Directory of Open Access Journals: DOAJ Articles Handle The ENVELOPE(161.983,161.983,-78.000,-78.000) Solid Earth 10 2 581 598 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
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ftdoajarticles |
language |
English |
topic |
Geology QE1-996.5 Stratigraphy QE640-699 |
spellingShingle |
Geology QE1-996.5 Stratigraphy QE640-699 R. A. Beckel C. Juhlin The cross-dip correction as a tool to improve imaging of crooked-line seismic data: a case study from the post-glacial Burträsk fault, Sweden |
topic_facet |
Geology QE1-996.5 Stratigraphy QE640-699 |
description |
Understanding the development of post-glacial faults and their associated seismic activity is crucial for risk assessment in Scandinavia. However, imaging these features and their geological environment is complicated due to special challenges of their hardrock setting, such as weak impedance contrasts, often high noise levels and crooked acquisition lines. A crooked-line geometry can cause time shifts that seriously de-focus and deform reflections containing a cross-dip component. Advanced processing methods like swath 3-D processing and 3-D pre-stack migration can, in principle, handle the crooked-line geometry but may fail when the noise level is too high. For these cases, the effects of reflector cross-dip can be compensated for by introducing a linear correction term into the standard processing flow. However, existing implementations of the cross-dip correction rely on a slant stack approach which can, for some geometries, lead to a duplication of reflections. Here, we present a module for the cross-dip correction that avoids the reflection duplication problem by shifting the reflections prior to stacking. Based on tests with synthetic data, we developed an iterative processing scheme where a sequence consisting of cross-dip correction, velocity analysis and dip-moveout (DMO) correction is repeated until the stacked image converges. Using our new module to reprocess a reflection seismic profile over the post-glacial Burträsk fault in northern Sweden increased the image quality significantly. Strike and dip information extracted from the cross-dip analysis helped to interpret a set of southeast-dipping reflections as shear zones belonging to the regional-scale Burträsk Shear Zone (BSZ), implying that the BSZ itself is not a vertical but a southeast-dipping feature. Our results demonstrate that the cross-dip correction is a highly useful alternative to more sophisticated processing methods for noisy datasets. This highlights the often underestimated potential of rather simple but noise-tolerant methods in ... |
format |
Article in Journal/Newspaper |
author |
R. A. Beckel C. Juhlin |
author_facet |
R. A. Beckel C. Juhlin |
author_sort |
R. A. Beckel |
title |
The cross-dip correction as a tool to improve imaging of crooked-line seismic data: a case study from the post-glacial Burträsk fault, Sweden |
title_short |
The cross-dip correction as a tool to improve imaging of crooked-line seismic data: a case study from the post-glacial Burträsk fault, Sweden |
title_full |
The cross-dip correction as a tool to improve imaging of crooked-line seismic data: a case study from the post-glacial Burträsk fault, Sweden |
title_fullStr |
The cross-dip correction as a tool to improve imaging of crooked-line seismic data: a case study from the post-glacial Burträsk fault, Sweden |
title_full_unstemmed |
The cross-dip correction as a tool to improve imaging of crooked-line seismic data: a case study from the post-glacial Burträsk fault, Sweden |
title_sort |
cross-dip correction as a tool to improve imaging of crooked-line seismic data: a case study from the post-glacial burträsk fault, sweden |
publisher |
Copernicus Publications |
publishDate |
2019 |
url |
https://doi.org/10.5194/se-10-581-2019 https://doaj.org/article/01b2cb012cea414bb07e65f0c383aea8 |
long_lat |
ENVELOPE(161.983,161.983,-78.000,-78.000) |
geographic |
Handle The |
geographic_facet |
Handle The |
genre |
Northern Sweden |
genre_facet |
Northern Sweden |
op_source |
Solid Earth, Vol 10, Pp 581-598 (2019) |
op_relation |
https://www.solid-earth.net/10/581/2019/se-10-581-2019.pdf https://doaj.org/toc/1869-9510 https://doaj.org/toc/1869-9529 doi:10.5194/se-10-581-2019 1869-9510 1869-9529 https://doaj.org/article/01b2cb012cea414bb07e65f0c383aea8 |
op_doi |
https://doi.org/10.5194/se-10-581-2019 |
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Solid Earth |
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10 |
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581 |
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