Publication Date:
2023-09-12
Description:
The change of atmospheric pressure will lead to long-period noise (T〉10s) in the gravity observation data, which will cover up the weak geodynamic signals in the superconducting gravimeter (SG) records, such as the Slichter mode. Therefore, it is very important to select a reasonable atmospheric admittance value to eliminate atmospheric pressure noise. This paper studies a method to calculate the atmospheric admittance value, which can calculate the admittance value at the specified frequency. Taking the Mw9.0 earthquake in the Pacific Ocean of Tohoku, northeastern Japan, on March 11, 2011, as an example, the gravity and pressure data sampled at the same site of the global superconducting gravimeter stations are taken, and the effects of the time domain admittance value and the frequency-dependent admittance value on the extraction of the Slichter mode are discussed respectively, and the results are further verified by the multi-station superposition method; It is considered that the method of calculating the admittance value at the specified frequency is better; When detecting the weak signal of normal mode, this method is helpful to improve the signal-to-noise ratio, highlight the signal, and analyze the deep structure of the earth's interior.
Language:
English
Type:
info:eu-repo/semantics/conferenceObject
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