Spanish Navy’s Royal Observatory, in collaboration with the patrol boat Vigia, has deployed six seafloor seismometers about 90 miles southwest of Cape St. Vicente.

The installation has been done at depths ranging between 4,700 and 4,900 meters.

The devices consist of an anchor, buoys, seismic hydrophone sensor, data recording system, batteries, and an acoustic transducer that enables communications, Spanish Navy wrote.

It also carries a flag, a flash and a radio beacon, which help to locate the device when it rises to surface.

Seismometers remain anchored for 8 months before being collected.

The deployment of seismometers will allow the registration of tectonic movements in the Gulf of Cadiz.