How the movement of magnetic north could cost Redding almost $10 million

Jessica Skropanic
Redding Record Searchlight

Get ready to see northern lights in new places.

Earth’s magnetic north pole has been moving across the top of the world for centuries, but since 2014, it tripled its speed to more than 30 miles per year, scooting from Canada toward Siberia. Scientists aren't exactly sure why, but they're watching it closely to see what it does next.

Here’s how the change in magnetic north's location affects us.

First, know your norths

Magnetic north is one of two north poles.

The top of the world, the point where the planet spins, is called geographic north — sometimes referred to as true north, Shasta College geology and earth sciences professor Randal Reed said.

GPS uses satellite data to map locations using geographic north. That north doesn’t move. 

Now take out a compass or use a compass app. 

The compass needle points to magnetic north, one end of a sort of long rod-shaped magnet inside the planet's core, Reed said. That magnet creates the magnetic field around the planet.

The magnetic poles do move. Historically, they even occasionally change places.

Our airports need to repaint, repave runways to tune of $9.57 million

Magnetic north speeding up means those who use it to fly — and land — planes and navigate ships need updated information more often. Pilots use both north poles to navigate.

Updates can be costly, especially for small airports, Benton Air Center president Jim Ostrich said. Benton needs to repaint runway heading numbers more often.

Magnetic headings, the two numbers painted at each end of a runway, indicate a runway's direction in juxtaposition to magnetic north, its compass bearing. Magnetic north sits at the 360-degree point on a compass. Three numbers — 001 to 360 — show in which direction any line, including a runway, points on the compass circle. Runway heading numbers are rounded to the nearest tenth and the third number, a zero, is dropped.

Brandon Elwood, supervisor of airport operations and maintenance for the city of Redding , stands next to the 33 magnetic heading number at one end of Benton Airpark’s runway, which needs to be repainted to read 34 due to the magnetic variation.

For several years, the magnetic heading number on Benton’s runway has been 33 (330 degrees) in one direction, painted at one end of the runway, and 15 (150 degrees) at the other end.

“In truth it’s now 34 and 16,” Ostrich said.

Magnetic north tripling speed means we need to repaint every runway "just about everywhere on the planet," said Jim Wadleigh, airports manager for Redding Municipal Airport and Benton Airpark. 

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It's not just painting pavement, he said. Changing the heading numbers also requires changing the stripes, paving and some runway reconstruction to adhere to safety regulations. 

Replacing Benton's heading numbers will cost about $570,000, Wadleigh said. Cost to change Redding Municipal Airport's runway heading numbers from 16 and 34, to 17 and 35, and make related repairs and upgrades, will run about $9 million.

About 90% of the cost for both projects is covered by grants from the Federal Aviation Administration (FAA) , he said. The remainder is funded by the Airport Enterprise Fund.

The moving north pole means runway heading numbers at Redding Municipal Airport are now slightly off. The airport needs to change this number from 34 to 35 and make related repairs and upgrades estimated to cost about $9 million.

Changing runway numbers usually happens every 15 to 20 years, Wadleigh said. If magnetic north keeps moving at its current pace, those changes will have to happen more often.

Magnetic north on the move means the FAA has to republish flight charts at least every six months, Ostrich said. Also “navigation stations need to be periodically adjusted.”

Those changes shouldn't worry passengers, Reed said. Updates happen more frequently now, and most navigation relies on GPS first. Navigators also have other options such as radio waves and coastal landmarks.

Could northern lights show up over Redding?

Eventually, the northern lights might not be so northern.

Because northern lights go where magnetic north goes, they are also showing up farther south, Reed said.

If our wandering north pole is the beginning of a reversal of the magnetic poles — a phenomenon that happened many times in Earth’s history, magnetic north could take a trip around the world, Reed said. In that case, people living on the poles’ route “get to see the northern lights pass by.”

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The lights usually show up 1,500 miles around magnetic north, Reed said, but when solar winds are really active they may be seen farther away. Redding was treated to some northern lights in 2002 during unusually high solar wind activity.

Your backyard birdhouse may be empty

Arctic-dwelling snow geese migrate as far as 6,000 miles to the Sacramento Valley every winter to feed.

The shifting poles may affect some animals. These include migratory birds, butterflies, bats, dolphin and whales.

According to the National Oceanic and Atmospheric Administration (NOAA), scientists aren't entirely sure what makes animals able to sense the magnetic field, so it’s not known what shifts in the field might do.

“If you’re following the magnetic field, you should experience changes in the field’s intensity” as you move, Reed said. Small changes probably won’t affect animal behavior much, but if we get a big change — like a polar reversal, animals would have trouble finding their way.

Still, animal species would likely survive. Geologic evidence shows the time it takes for dramatic shifts to occur are "super-short,"  Reed said. "We don’t have fossil evidence that these (pole) reversals are tied to mass extinction.”

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Jessica Skropanic is features reporter for the Record Searchlight/USA Today Network. She covers lifestyle and entertainment stories, and weekly arts feature d.a.t.e.  Follow her on Twitter @RS_JSkropanic and on Facebook. Join Jessica in the Get Out! Nor Cal recreation Facebook group. To support and sustain this work, please subscribe today. Thank you.