Coseismic and Postseismic Crustal Deformation Associated With the 2016 Kumamoto Earthquake Sequence Revealed by PALSAR‐2 Pixel Tracking and InSAR
Abstract Coseismic and postseismic crustal deformations caused by earthquake episodes are important in understanding the mechanisms of these episodes as well as the fault rheology near an epicentral area. Specifically, interferometric synthetic aperture radar (InSAR) and synthetic aperture radar (SA...
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
American Geophysical Union (AGU)
2020-10-01
|
| Series: | Earth and Space Science |
| Subjects: | |
| Online Access: | https://doi.org/10.1029/2020EA001200 |
| _version_ | 1818096955373387776 |
|---|---|
| author | Yuji Himematsu Masato Furuya |
| author_facet | Yuji Himematsu Masato Furuya |
| author_sort | Yuji Himematsu |
| collection | DOAJ |
| description | Abstract Coseismic and postseismic crustal deformations caused by earthquake episodes are important in understanding the mechanisms of these episodes as well as the fault rheology near an epicentral area. Specifically, interferometric synthetic aperture radar (InSAR) and synthetic aperture radar (SAR) pixel tracking can depict high‐resolution crustal deformation fields associated with earthquakes and volcanic activities without installing on‐site observation instruments. In this study, we investigate the coseismic and postseismic near‐fault crustal deformations associated with the 2016 Kumamoto earthquake sequence in southwest Japan using ALOS‐2/PALSAR‐2 (Phased Array‐type L‐band SAR‐2) data. Coseismic three‐dimensional (3‐D) displacement fields inferred from PALSAR‐2 pixel tracking data showed 1.6 m of horizontal displacements and 2 m of subsidence at maximum, despite the mainshock focal mechanism that was dominated by strike‐slip components with N‐S extension axes. The locations of large displacement variations along surface ruptures due to the mainshock were almost identical to a region where infrastructure was damaged, thus implying the generation of strong ground seismic waves. By using conventional InSAR stacking, we inferred two independent quasi‐east‐west and quasi‐vertical displacement fields as cumulative postseismic deformations following the mainshock over a period of about 2 years. The near‐fault postseismic deformation represented complicated displacement characteristics that could not be explained by a single physical process. Deformation signals around Aso volcano were interpreted by the effects of postseismic physical processes as well as geological heterogeneous structures. |
| first_indexed | 2024-12-10T23:12:51Z |
| format | Article |
| id | doaj.art-9de6ee72899d47e7a3907e6bb25c03cd |
| institution | Directory Open Access Journal |
| issn | 2333-5084 |
| language | English |
| last_indexed | 2024-12-10T23:12:51Z |
| publishDate | 2020-10-01 |
| publisher | American Geophysical Union (AGU) |
| record_format | Article |
| series | Earth and Space Science |
| spelling | doaj.art-9de6ee72899d47e7a3907e6bb25c03cd2022-12-22T01:29:54ZengAmerican Geophysical Union (AGU)Earth and Space Science2333-50842020-10-01710n/an/a10.1029/2020EA001200Coseismic and Postseismic Crustal Deformation Associated With the 2016 Kumamoto Earthquake Sequence Revealed by PALSAR‐2 Pixel Tracking and InSARYuji Himematsu0Masato Furuya1Department of Natural History Sciences, Graduate School of Science Hokkaido University Sapporo JapanDepartment of Earth and Planetary Sciences, Faculty of Science Hokkaido University Sapporo JapanAbstract Coseismic and postseismic crustal deformations caused by earthquake episodes are important in understanding the mechanisms of these episodes as well as the fault rheology near an epicentral area. Specifically, interferometric synthetic aperture radar (InSAR) and synthetic aperture radar (SAR) pixel tracking can depict high‐resolution crustal deformation fields associated with earthquakes and volcanic activities without installing on‐site observation instruments. In this study, we investigate the coseismic and postseismic near‐fault crustal deformations associated with the 2016 Kumamoto earthquake sequence in southwest Japan using ALOS‐2/PALSAR‐2 (Phased Array‐type L‐band SAR‐2) data. Coseismic three‐dimensional (3‐D) displacement fields inferred from PALSAR‐2 pixel tracking data showed 1.6 m of horizontal displacements and 2 m of subsidence at maximum, despite the mainshock focal mechanism that was dominated by strike‐slip components with N‐S extension axes. The locations of large displacement variations along surface ruptures due to the mainshock were almost identical to a region where infrastructure was damaged, thus implying the generation of strong ground seismic waves. By using conventional InSAR stacking, we inferred two independent quasi‐east‐west and quasi‐vertical displacement fields as cumulative postseismic deformations following the mainshock over a period of about 2 years. The near‐fault postseismic deformation represented complicated displacement characteristics that could not be explained by a single physical process. Deformation signals around Aso volcano were interpreted by the effects of postseismic physical processes as well as geological heterogeneous structures.https://doi.org/10.1029/2020EA001200satellite SARcrustal deformationpixel trackingearthquakeInSAR |
| spellingShingle | Yuji Himematsu Masato Furuya Coseismic and Postseismic Crustal Deformation Associated With the 2016 Kumamoto Earthquake Sequence Revealed by PALSAR‐2 Pixel Tracking and InSAR Earth and Space Science satellite SAR crustal deformation pixel tracking earthquake InSAR |
| title | Coseismic and Postseismic Crustal Deformation Associated With the 2016 Kumamoto Earthquake Sequence Revealed by PALSAR‐2 Pixel Tracking and InSAR |
| title_full | Coseismic and Postseismic Crustal Deformation Associated With the 2016 Kumamoto Earthquake Sequence Revealed by PALSAR‐2 Pixel Tracking and InSAR |
| title_fullStr | Coseismic and Postseismic Crustal Deformation Associated With the 2016 Kumamoto Earthquake Sequence Revealed by PALSAR‐2 Pixel Tracking and InSAR |
| title_full_unstemmed | Coseismic and Postseismic Crustal Deformation Associated With the 2016 Kumamoto Earthquake Sequence Revealed by PALSAR‐2 Pixel Tracking and InSAR |
| title_short | Coseismic and Postseismic Crustal Deformation Associated With the 2016 Kumamoto Earthquake Sequence Revealed by PALSAR‐2 Pixel Tracking and InSAR |
| title_sort | coseismic and postseismic crustal deformation associated with the 2016 kumamoto earthquake sequence revealed by palsar 2 pixel tracking and insar |
| topic | satellite SAR crustal deformation pixel tracking earthquake InSAR |
| url | https://doi.org/10.1029/2020EA001200 |
| work_keys_str_mv | AT yujihimematsu coseismicandpostseismiccrustaldeformationassociatedwiththe2016kumamotoearthquakesequencerevealedbypalsar2pixeltrackingandinsar AT masatofuruya coseismicandpostseismiccrustaldeformationassociatedwiththe2016kumamotoearthquakesequencerevealedbypalsar2pixeltrackingandinsar |