Rahul Biswas, Prantik Mandal, Satish Saha, Raju Prathigadapa, M. Shekar, R. Vijaya Raghavan
{"title":"印度 Garhwal-Kumaun 喜马拉雅地区体波衰减的空间变化","authors":"Rahul Biswas, Prantik Mandal, Satish Saha, Raju Prathigadapa, M. Shekar, R. Vijaya Raghavan","doi":"10.1016/j.pepi.2024.107211","DOIUrl":null,"url":null,"abstract":"<div><p>We have investigated the spatial variation of body wave attenuation in Garhwal-Kumaun Himalaya region from the datasets of 465 well located earthquakes, recorded at 52 broadband stations between 2017 and 2020. The body wave attenuation parameters <span><math><msub><mi>Q</mi><mi>P</mi></msub></math></span> and <span><math><msub><mi>Q</mi><mi>S</mi></msub></math></span> were estimated at each station by applying the extended coda normalization method for five different central frequencies ranging from 1.5 to 18 Hz. Strong frequency-dependent body wave attenuation was observed at each station over the whole region. Also, we found a significant variation of <span><math><msub><mi>Q</mi><mi>P</mi></msub></math></span> and <span><math><msub><mi>Q</mi><mi>S</mi></msub></math></span> from north to south which is consistent with geotectonic diversity beneath the study region. We have also made separate estimations of frequency-dependent relations for Garhwal and Kumaun Himalaya region in order to investigate the lateral variation in attenuation characteristics, and obtained the frequency-dependent relations as follows: <span><math><msub><mi>Q</mi><mi>P</mi></msub><mo>=</mo><mfenced><mrow><mn>30</mn><mo>±</mo><mn>3</mn></mrow></mfenced><msup><mi>f</mi><mfenced><mrow><mn>1.05</mn><mo>±</mo><mn>0.05</mn></mrow></mfenced></msup></math></span>, <span><math><msub><mi>Q</mi><mi>S</mi></msub><mo>=</mo><mfenced><mrow><mn>143</mn><mo>±</mo><mn>20</mn></mrow></mfenced><msup><mi>f</mi><mfenced><mrow><mn>0.88</mn><mo>±</mo><mn>0.07</mn></mrow></mfenced></msup></math></span> for the Garhwal Himalaya region and <span><math><msub><mi>Q</mi><mi>P</mi></msub><mo>=</mo><mfenced><mrow><mn>31</mn><mo>±</mo><mn>1</mn></mrow></mfenced><msup><mi>f</mi><mfenced><mrow><mn>1.09</mn><mo>±</mo><mn>0.02</mn></mrow></mfenced></msup></math></span>, <span><math><msub><mi>Q</mi><mi>S</mi></msub><mo>=</mo><mfenced><mrow><mn>121</mn><mo>±</mo><mn>11</mn></mrow></mfenced><msup><mi>f</mi><mfenced><mrow><mn>1.00</mn><mo>±</mo><mn>0.04</mn></mrow></mfenced></msup></math></span> for the Kuamun Himalaya region. Obtained <span><math><mi>Q</mi></math></span> values indicate strong body wave attenuation for both the region with no significant lateral variation. It may suggest the presence of crustal level folding, faulting, aqueous fluids, and metamorphic fluids below both the regions. Also, the ratios of <span><math><msub><mi>Q</mi><mi>S</mi></msub></math></span>/<span><math><msub><mi>Q</mi><mi>P</mi></msub></math></span> are high (<span><math><mo>></mo><mn>1</mn></math></span>) for the entire analyzed frequency range, suggesting a significant level of heterogeneity and tectonic complexities in the crust of the study region.</p></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"352 ","pages":"Article 107211"},"PeriodicalIF":2.4000,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Spatial variation of body wave attenuation in Garhwal-Kumaun Himalaya region, India\",\"authors\":\"Rahul Biswas, Prantik Mandal, Satish Saha, Raju Prathigadapa, M. Shekar, R. Vijaya Raghavan\",\"doi\":\"10.1016/j.pepi.2024.107211\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>We have investigated the spatial variation of body wave attenuation in Garhwal-Kumaun Himalaya region from the datasets of 465 well located earthquakes, recorded at 52 broadband stations between 2017 and 2020. The body wave attenuation parameters <span><math><msub><mi>Q</mi><mi>P</mi></msub></math></span> and <span><math><msub><mi>Q</mi><mi>S</mi></msub></math></span> were estimated at each station by applying the extended coda normalization method for five different central frequencies ranging from 1.5 to 18 Hz. Strong frequency-dependent body wave attenuation was observed at each station over the whole region. Also, we found a significant variation of <span><math><msub><mi>Q</mi><mi>P</mi></msub></math></span> and <span><math><msub><mi>Q</mi><mi>S</mi></msub></math></span> from north to south which is consistent with geotectonic diversity beneath the study region. We have also made separate estimations of frequency-dependent relations for Garhwal and Kumaun Himalaya region in order to investigate the lateral variation in attenuation characteristics, and obtained the frequency-dependent relations as follows: <span><math><msub><mi>Q</mi><mi>P</mi></msub><mo>=</mo><mfenced><mrow><mn>30</mn><mo>±</mo><mn>3</mn></mrow></mfenced><msup><mi>f</mi><mfenced><mrow><mn>1.05</mn><mo>±</mo><mn>0.05</mn></mrow></mfenced></msup></math></span>, <span><math><msub><mi>Q</mi><mi>S</mi></msub><mo>=</mo><mfenced><mrow><mn>143</mn><mo>±</mo><mn>20</mn></mrow></mfenced><msup><mi>f</mi><mfenced><mrow><mn>0.88</mn><mo>±</mo><mn>0.07</mn></mrow></mfenced></msup></math></span> for the Garhwal Himalaya region and <span><math><msub><mi>Q</mi><mi>P</mi></msub><mo>=</mo><mfenced><mrow><mn>31</mn><mo>±</mo><mn>1</mn></mrow></mfenced><msup><mi>f</mi><mfenced><mrow><mn>1.09</mn><mo>±</mo><mn>0.02</mn></mrow></mfenced></msup></math></span>, <span><math><msub><mi>Q</mi><mi>S</mi></msub><mo>=</mo><mfenced><mrow><mn>121</mn><mo>±</mo><mn>11</mn></mrow></mfenced><msup><mi>f</mi><mfenced><mrow><mn>1.00</mn><mo>±</mo><mn>0.04</mn></mrow></mfenced></msup></math></span> for the Kuamun Himalaya region. Obtained <span><math><mi>Q</mi></math></span> values indicate strong body wave attenuation for both the region with no significant lateral variation. It may suggest the presence of crustal level folding, faulting, aqueous fluids, and metamorphic fluids below both the regions. Also, the ratios of <span><math><msub><mi>Q</mi><mi>S</mi></msub></math></span>/<span><math><msub><mi>Q</mi><mi>P</mi></msub></math></span> are high (<span><math><mo>></mo><mn>1</mn></math></span>) for the entire analyzed frequency range, suggesting a significant level of heterogeneity and tectonic complexities in the crust of the study region.</p></div>\",\"PeriodicalId\":54614,\"journal\":{\"name\":\"Physics of the Earth and Planetary Interiors\",\"volume\":\"352 \",\"pages\":\"Article 107211\"},\"PeriodicalIF\":2.4000,\"publicationDate\":\"2024-05-13\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Physics of the Earth and Planetary Interiors\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0031920124000694\",\"RegionNum\":3,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"GEOCHEMISTRY & GEOPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physics of the Earth and Planetary Interiors","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0031920124000694","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
Spatial variation of body wave attenuation in Garhwal-Kumaun Himalaya region, India
We have investigated the spatial variation of body wave attenuation in Garhwal-Kumaun Himalaya region from the datasets of 465 well located earthquakes, recorded at 52 broadband stations between 2017 and 2020. The body wave attenuation parameters and were estimated at each station by applying the extended coda normalization method for five different central frequencies ranging from 1.5 to 18 Hz. Strong frequency-dependent body wave attenuation was observed at each station over the whole region. Also, we found a significant variation of and from north to south which is consistent with geotectonic diversity beneath the study region. We have also made separate estimations of frequency-dependent relations for Garhwal and Kumaun Himalaya region in order to investigate the lateral variation in attenuation characteristics, and obtained the frequency-dependent relations as follows: , for the Garhwal Himalaya region and , for the Kuamun Himalaya region. Obtained values indicate strong body wave attenuation for both the region with no significant lateral variation. It may suggest the presence of crustal level folding, faulting, aqueous fluids, and metamorphic fluids below both the regions. Also, the ratios of / are high () for the entire analyzed frequency range, suggesting a significant level of heterogeneity and tectonic complexities in the crust of the study region.
期刊介绍:
Launched in 1968 to fill the need for an international journal in the field of planetary physics, geodesy and geophysics, Physics of the Earth and Planetary Interiors has now grown to become important reading matter for all geophysicists. It is the only journal to be entirely devoted to the physical and chemical processes of planetary interiors.
Original research papers, review articles, short communications and book reviews are all published on a regular basis; and from time to time special issues of the journal are devoted to the publication of the proceedings of symposia and congresses which the editors feel will be of particular interest to the reader.