Last Monday, September 19, a 7.6 magnitude earthquake struck Mexico’s Pacific coast at 11:05 a.m. local time.
Five minutes later and 2,400 kilometers (1,500 miles) away, a researcher in California’s Death Valley National Park noticed something strange.
Life sciences technician Ambre Chaudoin was peering into the famous limestone cavern known as Devils Hole when the normally tranquil entrance to the desert aquifer began to whirl and whirl.
“It’s a big earthquake, wherever it is,” Chaudoin is heard saying in the background of her recordings.
“I don’t think I’ve ever been here when there was such a big earthquake.”
Soon Chaudoin’s voice and the voices of others around her were drowned out by the crashing and sucking waves, which the US National Park Service (NPS) later announced were over three feet tall at 11:35 a.m.
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When an earthquake stirs up a lake or partially enclosed body of water, it’s technically called a seiche. But when this occurs in an arid environment like Death Valley National Park, it’s colloquially referred to as a “desert tsunami.”
While not nearly as huge as an ocean tsunami, these waves are much larger than what is typically seen in this partially filled cave.
“Devil’s Hole is a window into this vast aquifer and an unusual indicator of seismic activity around the world,” the NPS website said in a statement.
“Major earthquakes in Japan, Indonesia and Chile have caused the water in Devils Hole to ‘slosh’ like water in a bathtub.”
These earthquake-triggered waves have previously reached heights of up to 2 meters, and during these extreme events, the water can tear algae and diatoms from the loch’s sunlit shelf.
That can be a serious problem for the hole’s isolated pupfish population, which has foraged and spawned on the cave’s shelf for over 10,000 years.
Today are Devils Hole pupfish (Cyprinodon diabolis) are critically endangered, although their numbers have shown signs of recovery recently.
Nine years ago there were only 75 pupfish left in Devils Hole. That year, an official tally reached 175 in March.
It’s not yet clear why pupfish are suffering in Devils Hole. Not every desert tsunami is a deadly event for these creatures, but they are certainly a risk factor given the limited nutrients available in the 152-meter (500-foot) deep habitat.
Waves in Devils Hole can actually help the ecosystem by ridding the shelf of organic matter that can deplete the aquifer of oxygen over time.
“This species resets the system,” said Kevin Wilson, an NPS aquatic ecologist LA times.
But if these waves are strong enough, they can also wash away too much.
Fortunately, no dead pup fish were found after the Mexico earthquake, but it’s unclear how much algae the waves swept away or how many fish eggs the splashes crushed.
The recent phenomenon is a good reminder that a disaster in one part of the world can very well impact an overlooked ecosystem or species thousands of miles away.
