Area 51 experienced at least 17 earthquakes in a single day this week, with stumped experts admitting the behavior is highly “unusual.”

The secretive Nevada Air Force base, long associated with reports of UFOs, was hit by comparatively shallow quakes, prompting conspiracy theories about nuclear testing.

The cluster of earthquakes ranged in magnitude from 2.5 to 4.4 and struck near the base, which is about 80 miles from Las Vegas, according to US Geological Survey (USGS) data.

Area 51 experienced 17 earthquakes in a single day. Getty Images

The first, most powerful quake, struck 2.5 miles below ground just after 3 p.m.…