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Lateral Variation of Crustal Lg Attenuation in Eastern North America
We perform Q(Lg) tomography for the northeastern part of North America. Vertical broadband seismograms of 473 crustal earthquakes recorded by 302 stations are processed to extract the Lg amplitude spectra. Tomographic inversions are independently conducted at 58 discrete frequencies distributed even...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group UK
2018
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5940689/ https://www.ncbi.nlm.nih.gov/pubmed/29740108 http://dx.doi.org/10.1038/s41598-018-25649-5 |
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author | Zhao, Lian-Feng Mousavi, S. Mostafa |
author_facet | Zhao, Lian-Feng Mousavi, S. Mostafa |
author_sort | Zhao, Lian-Feng |
collection | PubMed |
description | We perform Q(Lg) tomography for the northeastern part of North America. Vertical broadband seismograms of 473 crustal earthquakes recorded by 302 stations are processed to extract the Lg amplitude spectra. Tomographic inversions are independently conducted at 58 discrete frequencies distributed evenly in log space between 0.1 and 20.0 Hz. This relatively large dataset with good ray coverage allows us to image lateral variation of the crustal attenuation over the region. Obtained Q(Lg) maps at broadband and individual frequencies provide new insights into the crustal attenuation of the region and its relationship to geological structures and past tectonic activity in the area. The Q(Lg) shows more uniform values over the older, colder, and drier Canadian Shield, in contrast to higher variations in the younger margins. Results confirm the correlation of large-scale variations with crustal geological features in the area. Existence of low-velocity anomalies, thick sediments, volcanic rocks, and thin oceanic crust are potential sources of observed anomalies. The mean Q values are inversely correlated with average heat flow/generation for main geological provinces. |
format | Online Article Text |
id | pubmed-5940689 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | Nature Publishing Group UK |
record_format | MEDLINE/PubMed |
spelling | pubmed-59406892018-05-11 Lateral Variation of Crustal Lg Attenuation in Eastern North America Zhao, Lian-Feng Mousavi, S. Mostafa Sci Rep Article We perform Q(Lg) tomography for the northeastern part of North America. Vertical broadband seismograms of 473 crustal earthquakes recorded by 302 stations are processed to extract the Lg amplitude spectra. Tomographic inversions are independently conducted at 58 discrete frequencies distributed evenly in log space between 0.1 and 20.0 Hz. This relatively large dataset with good ray coverage allows us to image lateral variation of the crustal attenuation over the region. Obtained Q(Lg) maps at broadband and individual frequencies provide new insights into the crustal attenuation of the region and its relationship to geological structures and past tectonic activity in the area. The Q(Lg) shows more uniform values over the older, colder, and drier Canadian Shield, in contrast to higher variations in the younger margins. Results confirm the correlation of large-scale variations with crustal geological features in the area. Existence of low-velocity anomalies, thick sediments, volcanic rocks, and thin oceanic crust are potential sources of observed anomalies. The mean Q values are inversely correlated with average heat flow/generation for main geological provinces. Nature Publishing Group UK 2018-05-08 /pmc/articles/PMC5940689/ /pubmed/29740108 http://dx.doi.org/10.1038/s41598-018-25649-5 Text en © The Author(s) 2018 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. |
spellingShingle | Article Zhao, Lian-Feng Mousavi, S. Mostafa Lateral Variation of Crustal Lg Attenuation in Eastern North America |
title | Lateral Variation of Crustal Lg Attenuation in Eastern North America |
title_full | Lateral Variation of Crustal Lg Attenuation in Eastern North America |
title_fullStr | Lateral Variation of Crustal Lg Attenuation in Eastern North America |
title_full_unstemmed | Lateral Variation of Crustal Lg Attenuation in Eastern North America |
title_short | Lateral Variation of Crustal Lg Attenuation in Eastern North America |
title_sort | lateral variation of crustal lg attenuation in eastern north america |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5940689/ https://www.ncbi.nlm.nih.gov/pubmed/29740108 http://dx.doi.org/10.1038/s41598-018-25649-5 |
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