A magnitude 7.6 earthquake rattled Mexico's Pacific coast on Monday and left at least two people dead in its wake. Repercussions of the tremor extended as far as 1,500 miles north, where four-foot-tall waves began churning inside a Death Valley cave called Devils Hole, in what the National Park Service called a "surprising quirk of geology."
Video footage of the phenomenon — which is technically known as a seiche, when sudden changes are observed in a lake or partially enclosed body of water — shows a birds-eye view of the cave as its initially still water erupts into a series of waves that roil and crash intermittently over the course of several minutes.
Devils Hole is a geothermal pool within a limestone cave, located in a section of Death Valley near the border of Nevada and California. The cave itself is hundreds of feet deep, as the park service noted in a news release explaining the "desert tsunami" recorded late Monday morning, but its relatively shallow water level is crucial for the endangered marine species, called pupfish, that live there.
The fish, whose naturally-occurring population totaled just 175 earlier this year, feed on algae "that grows on a shallow, sunlit shelf" in Devils Hole, according to the park service.
Because Monday's seiche removed algae that had been growing in the cave, it will reduce the pupfish's food supply in the short term. But Kevin Wilson, an aquatic ecologist with the federal agency, suggested that the creatures may be resilient enough to withstand the temporary shift in their environment.
"The pupfish have survived several of these events in recent years," Wilson said in a statement. "We didn't find any dead fish after the waves stopped." An annual count to tally the pupfish inside Devils Hole is set to take place this upcoming weekend, the park service said.
Monday's earthquake was the first of two powerful tremors that shook Mexico this week. A second happened further inland near the country's capital, Mexico City, early on Thursday. It was given a preliminary magnitude of 6.8, and killed at least one person while causing buildings to sway.
