Rheology of the Northern Tibetan Plateau Lithosphere Inferred from the Post-Seismic Deformation Resulting from the 2001 Mw 7.8 Kokoxili Earthquake
Time-series observations from Sentinel-1 A/B InSAR spanning November 2014 to July 2021 were used to study the late post-seismic deformation velocity field arising from the Kokoxili earthquake. The deformation velocity caused by the interseismic slip along the major active faults in Tibet was first s...
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-03-01
|
| Series: | Remote Sensing |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2072-4292/14/5/1207 |
| _version_ | 1797473896376565760 |
|---|---|
| author | Xiaoran Lv Yun Shao |
| author_facet | Xiaoran Lv Yun Shao |
| author_sort | Xiaoran Lv |
| collection | DOAJ |
| description | Time-series observations from Sentinel-1 A/B InSAR spanning November 2014 to July 2021 were used to study the late post-seismic deformation velocity field arising from the Kokoxili earthquake. The deformation velocity caused by the interseismic slip along the major active faults in Tibet was first simulated. Comparing the simulated deformation velocity with the observed one, the maximum ratio of the simulated deformation velocity to the observed one was found to be 42%, indicating continuity in the viscoelastic relaxation caused by the 2001 Kokoxili earthquake. Subsequently, the rheological structure of the Kokoxili region was explored using a mixed model comprising the viscoelastic relaxation mechanism and the buried elastic dislocation model. The best estimated viscosities for the lower crust and upper mantle were <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi mathvariant="sans-serif">η</mi><mrow><mi>lc</mi></mrow></msub><mo>=</mo><msubsup><mn>1</mn><mrow><mo>−</mo><mn>0.44</mn></mrow><mrow><mo>+</mo><mn>0.78</mn></mrow></msubsup><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mn>19</mn></mrow></msup><mrow><mo> </mo><mi>Pas</mi></mrow></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi mathvariant="sans-serif">η</mi><mrow><mi>um</mi></mrow></msub><mo>=</mo><msubsup><mn>1</mn><mrow><mo>+</mo><mn>0</mn></mrow><mrow><mo>+</mo><mn>0.78</mn></mrow></msubsup><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mn>20</mn></mrow></msup><mrow><mo> </mo><mi>Pas</mi></mrow></mrow></semantics></math></inline-formula>, respectively. The results obtained in this study were compared with those of previous studies that used the early post-seismic displacement ranging from 0 to 6.5 years following the earthquake. The obtained value was largely the same as the previously estimated steady-state viscosity, which means that the viscosities of the viscoelastic layer beneath the Kokoxili regions have almost reached their stable state. Furthermore, the effective lower crustal viscosity of the Kokoxili region exhibited a logarithmic trend with time. |
| first_indexed | 2024-03-09T20:23:12Z |
| format | Article |
| id | doaj.art-52254891593a44fc9aabcaa22e8757d1 |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-03-09T20:23:12Z |
| publishDate | 2022-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-52254891593a44fc9aabcaa22e8757d12023-11-23T23:43:07ZengMDPI AGRemote Sensing2072-42922022-03-01145120710.3390/rs14051207Rheology of the Northern Tibetan Plateau Lithosphere Inferred from the Post-Seismic Deformation Resulting from the 2001 Mw 7.8 Kokoxili EarthquakeXiaoran Lv0Yun Shao1Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100094, ChinaAerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100094, ChinaTime-series observations from Sentinel-1 A/B InSAR spanning November 2014 to July 2021 were used to study the late post-seismic deformation velocity field arising from the Kokoxili earthquake. The deformation velocity caused by the interseismic slip along the major active faults in Tibet was first simulated. Comparing the simulated deformation velocity with the observed one, the maximum ratio of the simulated deformation velocity to the observed one was found to be 42%, indicating continuity in the viscoelastic relaxation caused by the 2001 Kokoxili earthquake. Subsequently, the rheological structure of the Kokoxili region was explored using a mixed model comprising the viscoelastic relaxation mechanism and the buried elastic dislocation model. The best estimated viscosities for the lower crust and upper mantle were <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi mathvariant="sans-serif">η</mi><mrow><mi>lc</mi></mrow></msub><mo>=</mo><msubsup><mn>1</mn><mrow><mo>−</mo><mn>0.44</mn></mrow><mrow><mo>+</mo><mn>0.78</mn></mrow></msubsup><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mn>19</mn></mrow></msup><mrow><mo> </mo><mi>Pas</mi></mrow></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi mathvariant="sans-serif">η</mi><mrow><mi>um</mi></mrow></msub><mo>=</mo><msubsup><mn>1</mn><mrow><mo>+</mo><mn>0</mn></mrow><mrow><mo>+</mo><mn>0.78</mn></mrow></msubsup><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mn>20</mn></mrow></msup><mrow><mo> </mo><mi>Pas</mi></mrow></mrow></semantics></math></inline-formula>, respectively. The results obtained in this study were compared with those of previous studies that used the early post-seismic displacement ranging from 0 to 6.5 years following the earthquake. The obtained value was largely the same as the previously estimated steady-state viscosity, which means that the viscosities of the viscoelastic layer beneath the Kokoxili regions have almost reached their stable state. Furthermore, the effective lower crustal viscosity of the Kokoxili region exhibited a logarithmic trend with time.https://www.mdpi.com/2072-4292/14/5/1207InSAR time series algorithmTibetan Plateaupost-seismic deformation mechanismviscoelastic relaxation |
| spellingShingle | Xiaoran Lv Yun Shao Rheology of the Northern Tibetan Plateau Lithosphere Inferred from the Post-Seismic Deformation Resulting from the 2001 Mw 7.8 Kokoxili Earthquake Remote Sensing InSAR time series algorithm Tibetan Plateau post-seismic deformation mechanism viscoelastic relaxation |
| title | Rheology of the Northern Tibetan Plateau Lithosphere Inferred from the Post-Seismic Deformation Resulting from the 2001 Mw 7.8 Kokoxili Earthquake |
| title_full | Rheology of the Northern Tibetan Plateau Lithosphere Inferred from the Post-Seismic Deformation Resulting from the 2001 Mw 7.8 Kokoxili Earthquake |
| title_fullStr | Rheology of the Northern Tibetan Plateau Lithosphere Inferred from the Post-Seismic Deformation Resulting from the 2001 Mw 7.8 Kokoxili Earthquake |
| title_full_unstemmed | Rheology of the Northern Tibetan Plateau Lithosphere Inferred from the Post-Seismic Deformation Resulting from the 2001 Mw 7.8 Kokoxili Earthquake |
| title_short | Rheology of the Northern Tibetan Plateau Lithosphere Inferred from the Post-Seismic Deformation Resulting from the 2001 Mw 7.8 Kokoxili Earthquake |
| title_sort | rheology of the northern tibetan plateau lithosphere inferred from the post seismic deformation resulting from the 2001 mw 7 8 kokoxili earthquake |
| topic | InSAR time series algorithm Tibetan Plateau post-seismic deformation mechanism viscoelastic relaxation |
| url | https://www.mdpi.com/2072-4292/14/5/1207 |
| work_keys_str_mv | AT xiaoranlv rheologyofthenortherntibetanplateaulithosphereinferredfromthepostseismicdeformationresultingfromthe2001mw78kokoxiliearthquake AT yunshao rheologyofthenortherntibetanplateaulithosphereinferredfromthepostseismicdeformationresultingfromthe2001mw78kokoxiliearthquake |