Luna Fiber Optic Accelerometers Capture Seismic Measurements During Earthquake Despite Power and Cellular Outages

On Aug. 9, 2020, accelerometers being used for a security project at Luna’s Atlanta office detected a magnitude 5.1 earthquake in Sparta, NC, USA.   Luna’s os7520 optical accelerometers buried in the soil just below the surface measured the earthquake’s vibration wave as it arrived in Atlanta approximately 2 minutes after the original quake:

Luna accelerometer NC quake capture

Signals from three buried os7520 fiber optic accelerometers showing earthquake signature

The os7520 sensors combined with a HYPERION interrogator enable high-performance vibration monitoring. The all-optical sensors, which can measure vibrations from nearby footsteps to aircraft flying overhead, have no electrical connections and are entirely passive. Luna’s solution enables cost effective, time-synchronized monitoring of up to 128 sensors with a single interrogator over a range of many kilometers – opening the door to large scale vibration monitoring not achievable with any other technique. The vibration or seismic data shown above was acquired with the prototype system described in a previous blog.

The data captured by the Luna sensors correlates well with the other seismic readings from USGS geological stations in the vicinity:

NC quake USGS seismographs capture

What’s interesting to note is that the data from the Luna accelerometer sensors was captured and retrieved despite multiple power and cellular outages in the area related to a regional storm, highlighting the ruggedness of the HYPERION and the cloud-connected monitoring system.   This result also highlights the exceptional performance of the os7520 vibration sensor, which can be used for wide-ranging applications, including perimeter and border security, structural monitoring, and both strong motion and long-range seismometry. 

Contact us for more information on os7520 sensors, HYPERION, and the cloud-connected monitoring system, and various applications in vibration monitoring.