Acceleration of Deep Slip Along the Longmenshan Fault Plane Before the 2008 M8.0 Wenchuan Earthquake
The first step toward earthquake forecasting is the identification of variables whose spatio-temporal variation can be connected with pre-seismic crustal deformation. Four periods of campaign Global Positioning System (GPS) observations around the Longmenshan fault zone (LFZ) provide important insig...
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Frontiers Media S.A.
2022-03-01
|
| Series: | Frontiers in Earth Science |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/articles/10.3389/feart.2022.830317/full |
| _version_ | 1811271684116709376 |
|---|---|
| author | Jing Zhao Jing Zhao Zhengyi Yuan Jinwei Ren Zaisen Jiang Qi Yao Zhihua Zhou Chong Yue Jun Zhong Anfu Niu |
| author_facet | Jing Zhao Jing Zhao Zhengyi Yuan Jinwei Ren Zaisen Jiang Qi Yao Zhihua Zhou Chong Yue Jun Zhong Anfu Niu |
| author_sort | Jing Zhao |
| collection | DOAJ |
| description | The first step toward earthquake forecasting is the identification of variables whose spatio-temporal variation can be connected with pre-seismic crustal deformation. Four periods of campaign Global Positioning System (GPS) observations around the Longmenshan fault zone (LFZ) provide important insights in crustal deformation and deep fault slip before the 2008 M8.0 Wenchuan earthquake. By using TDEFNODE to invert the coupling fraction and dynamic slip deficit rate of the Longmenshan fault plane before the Wenchuan earthquake, we show that under a background of strong coupling, the compressive slip deficit rate perpendicular to fault increased slightly at first and then decreased; a value of ∼1.5–3.6 mm/a along the central–southern segment from 1999 to 2001 increased to ∼1.9–3.9 mm/a from 2001 to 2004, and then decreased to ∼1.1–2.6 mm/a from 2004 to 2007. The dextral slip deficit rate parallel to fault was ∼6 mm/a from 1999 to 2004, before increasing significantly to ∼9.5 mm/a from 2004 to 2007, when the compressive slip deficit rate decreased. At the same time, large-scale GPS velocity profiles show that compressive shortening deformation in the Eastern Tibet Block, perpendicular to fault, increased slightly from 2001 to 2004, and then decreased from 2004 to 2007. Meanwhile, the dextral shear deformation parallel to fault near the LFZ increased significantly from 2004 to 2007. These findings are in good agreement with those calculated using repeating earthquake sequences, indicating that the deep slip rate of the Longmenshan fault plane may have accelerated several years before the Wenchuan earthquake. Our results demonstrate that GPS data can record pre-seismic preparatory processes, and have the potential for use in medium-term large earthquake forecasting. |
| first_indexed | 2024-04-12T22:24:17Z |
| format | Article |
| id | doaj.art-a9741e10f102425c8ea264822152f66d |
| institution | Directory Open Access Journal |
| issn | 2296-6463 |
| language | English |
| last_indexed | 2024-04-12T22:24:17Z |
| publishDate | 2022-03-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Earth Science |
| spelling | doaj.art-a9741e10f102425c8ea264822152f66d2022-12-22T03:14:13ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632022-03-011010.3389/feart.2022.830317830317Acceleration of Deep Slip Along the Longmenshan Fault Plane Before the 2008 M8.0 Wenchuan EarthquakeJing Zhao0Jing Zhao1Zhengyi Yuan2Jinwei Ren3Zaisen Jiang4Qi Yao5Zhihua Zhou6Chong Yue7Jun Zhong8Anfu Niu9China Earthquake Networks Center, Beijing, ChinaInstitute of Geology, China Earthquake Administration, Beijing, ChinaChina Earthquake Networks Center, Beijing, ChinaInstitute of Earthquake Forecasting, China Earthquake Administration, Beijing, ChinaInstitute of Earthquake Forecasting, China Earthquake Administration, Beijing, ChinaInstitute of Earthquake Forecasting, China Earthquake Administration, Beijing, ChinaChina Earthquake Networks Center, Beijing, ChinaChina Earthquake Networks Center, Beijing, ChinaChina Earthquake Networks Center, Beijing, ChinaChina Earthquake Networks Center, Beijing, ChinaThe first step toward earthquake forecasting is the identification of variables whose spatio-temporal variation can be connected with pre-seismic crustal deformation. Four periods of campaign Global Positioning System (GPS) observations around the Longmenshan fault zone (LFZ) provide important insights in crustal deformation and deep fault slip before the 2008 M8.0 Wenchuan earthquake. By using TDEFNODE to invert the coupling fraction and dynamic slip deficit rate of the Longmenshan fault plane before the Wenchuan earthquake, we show that under a background of strong coupling, the compressive slip deficit rate perpendicular to fault increased slightly at first and then decreased; a value of ∼1.5–3.6 mm/a along the central–southern segment from 1999 to 2001 increased to ∼1.9–3.9 mm/a from 2001 to 2004, and then decreased to ∼1.1–2.6 mm/a from 2004 to 2007. The dextral slip deficit rate parallel to fault was ∼6 mm/a from 1999 to 2004, before increasing significantly to ∼9.5 mm/a from 2004 to 2007, when the compressive slip deficit rate decreased. At the same time, large-scale GPS velocity profiles show that compressive shortening deformation in the Eastern Tibet Block, perpendicular to fault, increased slightly from 2001 to 2004, and then decreased from 2004 to 2007. Meanwhile, the dextral shear deformation parallel to fault near the LFZ increased significantly from 2004 to 2007. These findings are in good agreement with those calculated using repeating earthquake sequences, indicating that the deep slip rate of the Longmenshan fault plane may have accelerated several years before the Wenchuan earthquake. Our results demonstrate that GPS data can record pre-seismic preparatory processes, and have the potential for use in medium-term large earthquake forecasting.https://www.frontiersin.org/articles/10.3389/feart.2022.830317/fullwenchuan earthquakelongmenshan fault zonefault coupling fractionGPS velocity profilesacceleration process of deep slip ratepre-seismic preparatory processes |
| spellingShingle | Jing Zhao Jing Zhao Zhengyi Yuan Jinwei Ren Zaisen Jiang Qi Yao Zhihua Zhou Chong Yue Jun Zhong Anfu Niu Acceleration of Deep Slip Along the Longmenshan Fault Plane Before the 2008 M8.0 Wenchuan Earthquake Frontiers in Earth Science wenchuan earthquake longmenshan fault zone fault coupling fraction GPS velocity profiles acceleration process of deep slip rate pre-seismic preparatory processes |
| title | Acceleration of Deep Slip Along the Longmenshan Fault Plane Before the 2008 M8.0 Wenchuan Earthquake |
| title_full | Acceleration of Deep Slip Along the Longmenshan Fault Plane Before the 2008 M8.0 Wenchuan Earthquake |
| title_fullStr | Acceleration of Deep Slip Along the Longmenshan Fault Plane Before the 2008 M8.0 Wenchuan Earthquake |
| title_full_unstemmed | Acceleration of Deep Slip Along the Longmenshan Fault Plane Before the 2008 M8.0 Wenchuan Earthquake |
| title_short | Acceleration of Deep Slip Along the Longmenshan Fault Plane Before the 2008 M8.0 Wenchuan Earthquake |
| title_sort | acceleration of deep slip along the longmenshan fault plane before the 2008 m8 0 wenchuan earthquake |
| topic | wenchuan earthquake longmenshan fault zone fault coupling fraction GPS velocity profiles acceleration process of deep slip rate pre-seismic preparatory processes |
| url | https://www.frontiersin.org/articles/10.3389/feart.2022.830317/full |
| work_keys_str_mv | AT jingzhao accelerationofdeepslipalongthelongmenshanfaultplanebeforethe2008m80wenchuanearthquake AT jingzhao accelerationofdeepslipalongthelongmenshanfaultplanebeforethe2008m80wenchuanearthquake AT zhengyiyuan accelerationofdeepslipalongthelongmenshanfaultplanebeforethe2008m80wenchuanearthquake AT jinweiren accelerationofdeepslipalongthelongmenshanfaultplanebeforethe2008m80wenchuanearthquake AT zaisenjiang accelerationofdeepslipalongthelongmenshanfaultplanebeforethe2008m80wenchuanearthquake AT qiyao accelerationofdeepslipalongthelongmenshanfaultplanebeforethe2008m80wenchuanearthquake AT zhihuazhou accelerationofdeepslipalongthelongmenshanfaultplanebeforethe2008m80wenchuanearthquake AT chongyue accelerationofdeepslipalongthelongmenshanfaultplanebeforethe2008m80wenchuanearthquake AT junzhong accelerationofdeepslipalongthelongmenshanfaultplanebeforethe2008m80wenchuanearthquake AT anfuniu accelerationofdeepslipalongthelongmenshanfaultplanebeforethe2008m80wenchuanearthquake |