[1]LIANG Hongbao,YANG Guohua.Vertical Deformation in the Northern Section of the North-South Seismic Belt before and after the Wenchuan MS8.0 Earthquake Based on GPS Data[J].Journal of Seismological Research,2021,44(04):613-621.
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Vertical Deformation in the Northern Section of the North-South Seismic Belt before and after the Wenchuan MS8.0 Earthquake Based on GPS Data
Journal of Seismological Research[ISSN 1000-0666/CN 53-1062/P] Volume:
44
Number of periods:
2021 04
Page number:
613-621
Column:
Public date:
2021-11-10
- Title:
- Vertical Deformation in the Northern Section of the North-South Seismic Belt before and after the Wenchuan MS8.0 Earthquake Based on GPS Data
- Keywords:
- Global Positioning System; the Wenchuan MS8.0 earthquake; the Northern section of the North-South Seismic Belt; vertical deformation
- CLC:
- P315.72
- DOI:
- -
- Abstract:
- In view of the influence of the 2008 Wenchuan MS8.0 earthquake on the vertical deformation of the northern segment of the North-South Seismic Belt,we calculate with high precision the multi-period GPS observation data during 1999-2016,the features of vertical deformation before and after earthquake are obtained by using the method of polyhedral function to eliminate annual motion and spatial filtering respectively.The results show that:① In the west side of the junctions of the Bayan Har Block and the South China Block,the vertical deformation attenuates from the east to the west in the form of an exponential function,while in the west side the vertical deformation attenuates from the west to the east in the form of a logarithmic function,and the attenuation in the east is greater than in the west.The vertical-deformation characteristics in the north are different from the ones in the south of the two Blocks' junctions.The uplift rate and the change gradient in the northern section are weaker than the ones in the southern section.② The vertical deformation of the Northern section of the North-South Seismic Belt before the Wenchuan earthquake was obviously different from the one after the earthquake.The uplift rate accelerates in most areas after the earthquake,with an average of about 2 mm/a and a maximum of 7 mm/a in the local area.The uplift rate of the local area decreases and the amplitude decreases within 2 mm/a.③ The variation of the vertical velocity has an effect on the vertical strain accumulation in the Crust.The largest positive influenced area is the junction of the Blocks and its western region,with increments about 10×10-8/a and about 2 times of the ones relative to pre-earthquake.The largest negative influenced region is the northern part of the Sichuan-Yunnan Block,with a reduction about 7×10-8/a.It is necessary to conduct an intensive GPS observation of the junction between the Bayan Har Block and the South China Block and its western region as well as the northern part of the Sichuan-Yunnan Block should be strengthened.
- References:
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- Similar References:
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Last Update:
2021-11-10