Gravity surveys using a mobile atom interferometer

TL;DR

This paper presents a portable atomic gravimeter capable of high-precision gravity measurements in the field, demonstrating its potential for geophysical and environmental applications.

Contribution

It introduces a simplified, mobile atomic gravimeter that achieves high sensitivity and stability, enabling practical field measurements of gravity variations.

Findings

Achieved a sensitivity of 37 μGal/√Hz in tidal measurements

Recorded ocean tidal loading effects and distant earthquakes

Surveyed gravity with 0.04 mGal accuracy in the field

Abstract

Mobile gravimetry is important in metrology, navigation, geodesy, and geophysics. Atomic gravimeters could be among the most accurate mobile gravimeters, but are currently constrained by being complex and fragile. Here, we demonstrate a mobile atomic gravimeter, measuring tidal gravity variations in the laboratory as well as surveying gravity in the field. The tidal gravity measurements achieve a sensitivity of 37 $\mu$Gal/$\sqrt{\rm Hz}$ and a long-term stability of better than 2 $\mu$Gal, revealing ocean tidal loading effects and recording several distant earthquakes. We survey gravity in the Berkeley Hills with an accuracy of around 0.04 mGal and determine the density of the subsurface rocks from the vertical gravity gradient. With simplicity and sensitivity, our instrument paves the way for bringing atomic gravimeters to field applications.