LAS VEGAS >> About 10 minutes after a powerful, magnitude-7.4 earthquake rattled southern Mexico last month, researchers outside Las Vegas were watching a tiny tsunami churn a normally tranquil spring pool 1,700 miles away.

Three National Park Service technicians were doing maintenance on data recorders at Devil’s Hole March 20 when the waters started surging more than 2 feet high. They grabbed a camera, and their video of the rare phenomenon now has more than 47,000 views on YouTube.

"It baffles me, but it makes sense. Everything’s kind of connected in a way," Jeffrey Goldstein, a park service biotechnician, tells the Las Vegas Review-Journal. "It’s weird. That’s about all I can say."

It’s not the first time far-away earthquakes have rocked Devil’s Hole, a flooded limestone cavern about 90 miles west of Las Vegas that’s technically located in Death Valley National Park.

Scientific instruments have recorded tremors there during the magnitude-9.0 quake and tsunami that shook Japan in March 2011 and during the magnitude-6.9 quake that hit western China in April 2010.

But earthquakes closer to home — include a magnitude-6.0 temblor that struck about 325 miles away and damaged buildings in northern Nevada — have barely registered a ripple.

"It depends a lot on the magnitude of the earthquake and the depth," said Kevin Wilson, a Death Valley aquatic ecologist for the National Park Service.

Researchers call Devil’s Hole, which extends more than 430 feet underground, "a window into the groundwater table." Water levels of the pool rise and fall slightly with the lunar cycle, and geothermal heat warms the water to about 93 degrees.

Seeing the earthquake shake the pool — much less capturing it on film — was an exceptionally rare event.

"There are more people that have walked on the moon than have witnessed an earthquake event at Devil’s Hole," Wilson said.

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Online: Video of the "desert tsunami": http://bit.ly/IdE4rB