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Exploration of Decadal Crustal Velocity Changes Associated With Tidal-Induced Strain Using Seismic Noise

Description: 

Earth’s tide modulates the volumetric strain within the subsurface that impacts groundwater level. Through in-situ measurement in a well, it is possible to deduce hydrological response (i.e., permeability) by analyzing the time lags between predicted tidal forces and the corresponding changes in water levels. In this presentation, we explore a non-invasive, single-station method to understand the capability of monitoring subsurface permeability using a decade of continuous seismic data from northern Chile. We extract coherent wavefields by 6-component noise correlation at a single station. The velocity variations are measured with a 30-minute resolution based on the changes in the coda wavefields of correlation functions at frequency range of 3–7 Hz over time. The seismic velocity reflects subsurface elasticity and is sensitive to ground motion, precipitation, pressure and temperature changes. Our decade-long, time-lapse velocity variations exhibit diurnal and semidiurnal cycles likely influenced by solar tides and radiation. Furthermore, we observe a robust semidiurnal cycle related to lunar tides, M2. The M2 cycle is expected to exclusively link to volumetric strain modulation and free from effects of thermal strain. Therefore, our discussion will center on the potential hydrological implications specifically focusing on the observed lunar tides cycle.

Session: ESC-SSA Joint Session: Climate Change and Environmental Seismology [Poster Session]

Type: Poster

Date: 5/3/2024

Presentation Time: 08:00 AM (local time)

Presenting Author: Sin-Mei

Student Presenter: No

Invited Presentation: 

Authors