When a magnitude-7.9 earthquake jolted Alaskans out of bed Tuesday, guess where else it was felt? Florida.
Within an hour after the quake hit at 4:32 a.m. Eastern time, groundwater 3,500 miles away in Fort Lauderdale dropped by an inch and a half. Up the coast in the state's Big Bend, it rose 2 inches in wells monitored in Madison, according to the U.S. Geological Survey.
Tsunamis are obviously the big threat when the earth's surface starts shifting. Tuesday's quake triggered warnings across Alaska's southern coast, British Columbia and the remainder of the U.S. West Coast for several hours. Residents fled to high ground and huddled in school shelters waiting for the all clear. The tsunami that followed, however, never reached more than 0.7 feet off Alaska.
[How waiting for a tsunami that didn't come turned a small-town Alaska man into an internet hero]
Less obvious are the tremors in water levels that can stretch far from a quake's epicenter.
When a magnitude-9.0 earthquake hit Japan in 2011, Florida's water table quivered from the Keys to Orlando. Haiti's devastating 2010 earthquake also shook up Florida's groundwater. In 1964, following Alaska's massive 9.2 quake, some state water tables spiked by as much as 20 feet. Blame the state's porous limestone, where water can flow more freely and quickly register changes.
Tuesday's fluctuations were likely triggered by seismic waves, USGS officials reported.
"Think of it as the ripples in a glass of water on a table when a truck drives by outside," they said.
If you missed this latest entry in Florida's freaky phenomena, you're not alone. Water levels returned to normal within minutes.
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