microGs

MicroGs, short for micro gravity sensors, are compact instruments designed to measure small variations in local gravitational acceleration. They are used in field geophysics, archaeology, hydrology, and civil engineering to detect mass redistribution, groundwater movement, or subsurface anomalies. The name emphasizes their micro-scale sensitivity and portable form factor.

Most microGs combine MEMS fabrication, precise signal processing, and environmental isolation. Many use MEMS accelerometers configured as gravimeters, sometimes with temperature stabilization. Other approaches employ optical readout or atom-interferometry techniques for higher precision. Readings are continually referenced to a baseline and corrected for drift using calibration routines or supplementary sensors.

Applications include monitoring groundwater tables, mapping buried voids or mineral deposits, tracking volcanic or tectonic activity, and informing infrastructure safety assessments such as slope stability and foundation settlement. Dense sensor networks enable rapid surveys in disaster zones and in exploration campaigns.

Limitations include environmental noise, mechanical vibration, temperature sensitivity, and calibration drift. Power consumption, ruggedness, and data processing in the field remain challenges. Interpreting gravity signals often requires integrating data with other geophysical measurements to separate gravity effects from non-gravitational sources.

Related topics include gravimetry, MEMS sensors, and quantum or atom-interferometry based gravimeters.