Quartz Enhanced Micro Electromechanical Systems Accelerometer for Seismic Monitoring: Field Performance in Volcanic Region

Abstract

This article introduces a novel Quartz micro electromechanical systems (QMEMSs) accelerometer, providing detailed insights into its design, system architecture, performance, and field testing. Diverging from traditional micro-electromechanical systems (MEMS) accelerometers, this device employs a quartz resonator as an acceleration-to-frequency transducer. The QMEMS-enhanced design features a double-ended tuning fork (DETF) resonator with high sensitivity (~120 Hz/G). The system includes a three-axis sensor module, open-loop oscillation circuits, and a sigma accumulation time-to-digital converter (TDC) for precise frequency measurement. The compact, aluminum-encased accelerometer, with a ±15 g dynamic range (DR), exhibits remarkable stability and performance under various temperatures. With a specific focus on seismicity monitoring applications, a field test was conducted in the volcanic region of Mt. Aso, Kyushu Island, Japan, comparing the accelerometer with a conventional velocity-type seismometer. Our result indicates that QMEMS accelerometer can detect high- and low-frequency earthquake signals comparable to the velocity-type seismometer by focusing the frequency band close to the frequency of the seismic events. This highlights its efficacy in capturing a broad spectrum of seismic activities in volcanic regions.