TAMPA — The skies of South Tampa are noticeably noisier these days, as dozens more planes heading into and out of Tampa International Airport are roaring over neighborhoods instead of Tampa Bay. The culprit, of all things, is a shifting magnetic north pole.
The pole's movement has forced the airport to install new signs on its runways, which are labeled with numbers according to compass headings. As the pole moves roughly 40 miles a year toward Russia, the numbers on the runways eventually get out of whack.
The good news: The first phase of the project ends Thursday, and most of the noise will leave South Tampa. The bad news: Flight patterns will shift during the second phase to hit those living around Carrollwood and Westchase with the sound of roaring jets for several weeks.
"It really sort of disturbs the peace out here," said Marlin Anderson, the president of the homeowners association in Sunset Park. "It'll interfere with my concentration. Because here comes a jet and then two or three minutes later, here comes another one."
Airport officials say they're sensitive to the noise concerns, noting that the runway updates are required by the Federal Aviation Administration. They're also using the opportunity to conduct routine maintenance such as repairing concrete and removing rubber deposits.
"We're doing everything we can do expedite the project," said airport spokeswoman Kelly Figley.
Runways are designated according to points on a compass, with 360 points spaced around a circle and split into 10-degree segments. When TIA's primary runway was built in the 1960s, it pointed almost exactly due north. One end was labeled 36, or 360 degrees. The other end was labeled 18, or 180 degrees.
Because the magnetic pole has moved, the runway now points closer to 10 degrees and 190 degrees.
Airport officials closed the primary runway on Monday to repaint numbers on the ground and replace signs. That runway will reopen Thursday, and the airport will close a parallel north-south runway and a shorter, rarely used east-west runway. Those runways will reopen after about two or three weeks of work.
This is the first time the designations have changed since the current Tampa International Airport opened in 1971. An FAA spokeswoman said they likely won't change "for a very long time."
Many people are surprised to hear that the Earth's magnetic pole is shifting. Magnetic north hovered over northern Canada when recordkeeping began about 400 years ago, said Joe Stoner, a geophysics professor at Oregon State University. During the past 100 years, it has shifted relatively quickly across the top of the globe toward Russia.
Stoner said scientists don't know exactly why the pole shifts, but it's affected by the movement of the Earth's liquid outer core around the solid inner core. Scientists also aren't certain about where the pole will go next. Stoner predicted it will slow down over the next few decades as it crosses the geographic north pole, and then speed up again as it heads toward Russia.
Back in Florida, Lenox Stevens doesn't worry much about the magnetic north pole. He pays more attention to airplane noise as he logs planes that fly over his home south of Gandy Boulevard. A frequent critic of TIA, he usually counts 20 on a given day, maybe 30. Earlier this week, he stopped at 25 — and it was only 11 a.m.
"This whole thing that's happening now, it's much worse," he said. "I don't understand why it takes 13 days (to relabel the runway). Why can't you be more considerate of the people who live around the airport?"
Margaret Vizzi, 69, is a longtime resident of Beach Park, where planes are lowest as they get ready to land at the airport. She's ready for the noise to end, but she also understands that the runway work is necessary. As part of a committee that works with the airport to reduce noise problems, she warned her neighbors about the disruption.
"I did not get as many calls as I thought I would," Vizzi said. "Everybody was more surprised about the axis of the Earth changing. That was more of the discussion than the noise."
Times staff writer Steve Huettel contributed to this report. Lee Logan can be reached at (813) 226-3383 or email@example.com.