Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10121226 | Physics of the Earth and Planetary Interiors | 2018 | 6 Pages |
Abstract
To investigate possible piezomagnetic effects associated with imposed tectonic stresses, repeated measurements of total magnetic field in an array (â¼120â¯kmâ¯Ãâ¯90â¯km in extent) were performed across the Hutubi underground gas storage (HUGS). Forty repeated measurement stations were established in the HUGS and its surrounding areas. Proton precession magnetometers with a sensitivity of 0.15â¯nT @ 1â¯Hz were used to measure the total magnetic field at each repeated station. We conducted two field measurement surveys, one with a minimum pressure during April 2017 and the other with a maximum pressure during November 2017 in the HUGS. The local magnetic field (LMF) of the HUGS and its surrounding areas was obtained after data processing, which included diurnal variation reduction (DVR), secular variation reduction (SVR) and LMF acquisition. The average of the mean standard deviations (Ï) of the geomagnetic DVR values were 0.038â¯nT and 0.045â¯nT for the first and second field surveys respectively. The amplitude of the LMF varied between about 10â¯nT and 90â¯nT in the local area. Negative anomalies with a maximum amplitude of â2.1â¯nT was observed over a seven-month period (April 2017-November 2017) during the loading process with a constantly increasing pressure in the HUGS. The wide range of negative LMF anomalies shows a negative correlation with the increasing pressure in the HUGS. This result constitutes powerful field observational evidence for the existence of piezomagnetic effects under middle-scale experimental conditions.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Geophysics
Authors
Zhendong Wang, Bin Chen, Jiehao Yuan, Fuxi Yang, Lu Jia, Can Wang,