Alaska earthquake had a ripple effect (literally) as far off as Florida

When a 7.9 magnitude earthquake jolted Alaskans out of bed on 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 two inches in wells monitored in Madison, according to the U.S. Geological Survey.

usgs quake table

Following Tuesday’s 7.9-magnitude earthquake in Alaska, seismic waves caused groundwater in Florida to shift, dropping more than an inch in Fort Lauderdale and rising two inches in Madison near the state’s Big Bend.

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.

Less obvious are the tremors in water levels that can stretch far from a quake’s epicenter.

When a 9.0-magnitude 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.

usga alaska quake map

U.S. Geological Survey

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.