Crustal movement and strain distribution in East Asia revealed by GPS observations

Ming Hao,Yuhang Li,Wenquan Zhuang

doi:10.1038/s41598-019-53306-y

Ming Hao, Yuhang Li + Show 1 more

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https://doi.org/10.1038/s41598-019-53306-y

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Journal: Scientific Reports	Publication Date: Nov 14, 2019
Citations: 24	License type: open-access

Affiliation: China Earthquake Administration

Abstract

East Asia is bounded by the Indian plate to the southwest and the Pacific and Philippine plates to the east, and has undergone complex tectonic evolution since ~55 Ma. In this study, we collect and process three sources of GPS datasets, including GPS observations, GPS positioning time series, and published GPS velocities, to derive unified velocity and strain rate fields for East Asia. We observed southward movement and arc-parallel extension along the Ryukyu Arc and propose that the maximum principal stress axis (striking NEE) in North China could be mainly induced by westward subduction of the Pacific plate and the southward movement of the Ryukyu Arc. The large EW-trending sinistral shear zone that bounds North China has been created by eastward movement of South China to the south and westward subduction of the Pacific plate to the north. GPS velocity profiles and strain rates also demonstrate that crustal deformation in mainland China is controlled by northeastward collision of the Indian plate into Eurasia and westward subduction of the Pacific and Philippine Sea plates beneath Eurasia. In particular, the India-Eurasia continental collision has the most extensive impact, which can reach as far as the southern Lake Baikal. The viscous behavior of the subducting Pacific slab also drives interseismic deformation of North China. The crustal deformation caused by Philippine oceanic subduction is small and is limited to the region between the southeast coast of mainland China and Taiwan island. However, the principal compressional strain around eastern Taiwan is the largest in the region.

Highlights

Cenozoic deformation of East Asia is complex due to the collision of India into Eurasia to the southwest and the Western Pacific and Philippine oceanic plates subducting under Eurasia to the east (Fig. 1)
We propose that westward movement of the Pacific plate and southward movement along the Ryukyu Arc could produce a principal compressive stress in the NE-SW direction, resulting in a maximum principal stress axis striking NEE in North China
The large EW-trending sinistral shear zone bounding North China could have possibly been created by eastward movement of South China to the south, and westward subduction of the Pacific plate to the north

Summary

Introduction

Cenozoic deformation of East Asia is complex due to the collision of India into Eurasia to the southwest and the Western Pacific and Philippine oceanic plates subducting under Eurasia to the east (Fig. 1). The advent of GPS has provided an accurate and efficient approach for measuring regional and large scale crustal deformation, which are crucial in the attempt to constrain the dynamic processes affecting East Asia. Our primary purpose in this study is to generate present-day unified GPS velocity and strain rate fields for East Asia, in order to analyze the patterns of crustal movement across key regions around East Asia. The GPS data collected and measured in mainland China are from the Crustal Movement Observation Network of China (CMONOC) These GPS stations were surveyed in 1998, 1999, 2001, 2004, and 2007. We used a linear function to fit the GPS time series, in order to estimate secular velocity rates with respect to ITRF2008

Results

Discussion

Conclusion