EGU2020-10096, updated on 12 Jun 2020
https://doi.org/10.5194/egusphere-egu2020-10096
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

High precision and high resolution monitoring of subsurface changes with DAS and airgun

Baoshan Wang1, Xiangfang Zeng2, Jun Yang3, Yuansheng Zhang4, Zhenghong Song1, Xiaobin Li3, Rongbin Lin2, Manzhong Qin4, and Congxin Wei4
Baoshan Wang et al.
  • 1University of Science and Technology of China, School of Earth and Space Sciences, China (bwgeo@ustc.edu.cn)
  • 2State Key Laboratory of Geodesy and Earth's Dynamics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences
  • 3Earthquake Agency of Yunnan Province
  • 4Earthquake Agency of Gansu Province

Recently large-volume airgun arrays have been used to explore and monitor the subsurface structure. The airgun array can generate highly repeatable seismic signals, which can be traced to more than 200 km. And the airgun source can be ignited every 10 minutes. The airgun source makes it possible to precisely monitor subsurface changes at large scale. The spatial resolution of airgun monitoring is poor subjecting to the receiver distribution. The distributed acoustic sensing (DAS) technique provides a strategy for low-cost and high-density seismic observations. Two experiments combing DAS technique and airgun source were conducted at two sites with different settings. At the first site, a telecommunication fiber-optic cable in urban area was used. After moderate stacking, the airgun signal emerges on the 30-km DAS array at about 9 km epicentral distance. In the second experiment, a 5-km cable was deployed from the airgun source to about 2 km away. About 800-m cable was frozen into the ice above the air-gun, the rest cable was cemented on the road crossing through a fault. And the airgun has been fired continuously for more than 48 hours with one-hour interval. On the stacking multiple shots’ records, the wavefield in fault zone emerges too. These two experiments demonstrate the feasibility of using various fiber-optic cables as dense array to acquire air-gun signal in different environments and to monitor the subsurface changes.

How to cite: Wang, B., Zeng, X., Yang, J., Zhang, Y., Song, Z., Li, X., Lin, R., Qin, M., and Wei, C.: High precision and high resolution monitoring of subsurface changes with DAS and airgun, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-10096, https://doi.org/10.5194/egusphere-egu2020-10096, 2020

Comments on the presentation

AC: Author Comment | CC: Community Comment | Report abuse

Presentation version 1 – uploaded on 03 May 2020 , no comments