Luna Accelerometer Senses Earthquake from 3,000 km Away
Fiber Optic Accelerometer Performs Long-Range Seismometry … and Much More
Accelerometers that were part of a pilot installation of a vibration-based security system at Luna’s Atlanta office detected a magnitude 7.1 earthquake, which occurred 18 km west of Searles Valley, California on July 6. Luna’s os7520 optical sensors detected and measured the vibration wave as it arrived in Atlanta 650 seconds later.
As part of the pilot vibration-based security system, sensors were buried in soil just below the surface. The setup was not optimized for seismic detection, since the sensors reside in a densely populated, high-traffic area in Atlanta.
The os7520 sensors combined with a HYPERION interrogator enable high performance vibration monitoring. The all-optical sensors have no electrical connections and are entirely passive. Up to 128 sensors can be monitored with a single interrogator. This data was acquired with a prototype system that monitors the sensor output 24/7 and automatically synchronizes to cloud databases over the cellular network, while also sending notifications of detected events. The main purpose of the pilot system is to create cost-effective vibration monitoring solutions for security applications.
This result demonstrates 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.
Figure 1 below shows the event as measured in Atlanta. For validation, Luna engineers also downloaded the waveform for the event from the nearest USGS monitoring station, shown in Figure 2. The timing and waveform structure clearly indicates that these waveforms correspond to the same event.
Contact us for more information on os7520 sensors and the various applications in vibration monitoring.