Sun's magnetic flip: 5 facts and myths about solar activity
Sun will soon reverse its magnetic field
As scientists keep a close eye on the sun’s impending magnetic flip, Canadians, it seems, will be keeping a close eye on any new developments.
News that the sun is reaching the midpoint of its solar cycle — the peak moment at which it is expected to reverse its magnetic field — became the most-viewed story on CBCNews.ca. Since there seems to be a keen interest in solar flares and solar cycles, here are some other interesting facts, or myths, related to solar activity.
1. Earth's magnetic field also flips
While the sun's magnetic field flips about every 10 to 13 years, the Earth's own field also flips, meaning that a compass that points to the north would eventually turn to the south.
But this happens much less frequently. Scientists estimate a flip occurs, on average, once every 200,000 years (although the last flip is said to have occurred 780,000 years ago). However, the process can take anywhere from 1,000 years to 10,000 years.
- Sun's pending magnetic flip has physicists on edge
- Quirks & Quarks: Hear an interview with solar astronomer Todd Hoksema about the solar flip
Although the flip would require some adaptation by humans, animals that use the Earth's magnetic field for directions could be affected, the British Geological Society said.
"Assuming that a reversal takes a number of thousand years, that is, over many generations of each species, each animal may well adapt to the changing magnetic environment, or develop different methods of navigation."
2. Can a solar flare wipe out the Earth?
The sun's magnetic flip is expected to increase the chance of significant solar flares, which are eruptions of magnetic energy from the sun’s surface. But these solar flares, when interacting with Earth's magnetic field, can knock out man-made satellites and power grids, affect navigation equipment on airplanes, and interfere with other electronics and communications systems.
In 1989, for example, a geomagnetic storm knocked out the Hydro-Québec power grid and left millions of people without electricity for up to nine hours.
Some have expressed concerns that a "killer solar flare" could destroy earth. But scientists say those fears are unfounded because the Earth's thick atmosphere stops radiation produced by a solar flare.
"Most importantly, however, there simply isn’t enough energy in the sun to send a killer fireball 93 million miles to destroy Earth," NASA said in a past statement. "Even at their worst, the sun's flares are not physically capable of destroying Earth."
3. But a bad geomagnetic storm can cause a lot of economic damage
A study by the National Academy of Sciences, titled Severe Space Weather Events — Understanding Societal and Economic Impacts, estimated that depending on the damage, societal and economic costs of a "severe geomagnetic storm scenario" could reach up to $1 trillion to $2 trillion with a recovery time of four to 10 years.
To put those figures into perspective, the costs of North America's northeast blackout in 2003 were estimated at $4 billion to $10 billion. Hurricane Katrina costs were estimated between $81 billion to $125 billion.
4. Sunspots affect the stock market?
Some market analysts believe there is a correlation between sunspot activity and financial markets and that the former may have an effect on the latter. For example, William Herschel believed the number of sunspots affected the price of wheat grain. Some analysts insist that solar activity has an effect on human emotions. This, they say, also impacts markets. So increased high intensity sunspot activity leads people to buy more and cause markets to rise and conversely, lower sunspot activity causes markets to go down. But the theory is dismissed by most scientists and economists.
5. Solar flares causing earthquakes?
For years, many have suggested that solar activity, in particular solar flares may cause or be linked to increased earthquake activity. But a recent study by researchers from the U.S. Geological Survey found no evidence of any correlation.
Researchers examined if there was a relationship between increased solar activity and the number of earthquakes.
"There have been some earthquakes like the 9.5 magnitude Chile quake in 1960 where, sure enough, there were more sunspots and more geomagnetic activity than on average,” Jeffrey Love, the leading researcher of the study, told Planet Earth Online. “But then for the Alaska earthquake in 1964 everything was lower than normal. There’s no obvious pattern between solar activity and seismicity, so our results were inconclusive.”