Earth's north magnetic pole is drifting away from North America and toward Siberia at such a clip that Alaska might lose its spectacular Northern Lights in the next 50 years, scientists have said.
Despite accelerated movement over the past century, the possibility that Earth's modestly fading magnetic field will collapse is remote. But the shift could mean Alaska may no longer see the sky lights known as auroras, which might then be more visible in more southerly areas of Siberia and Europe.
The magnetic poles are part of the magnetic field generated by liquid iron in the Earth's core and are different from the geographic poles, the surface points marking the axis of the planet's rotation.
Scientists have long known that magnetic poles migrate and in rare cases, swap places. Exactly why this happens is a mystery.
``This may be part of a normal oscillation and it will eventually migrate back toward Canada,'' Joseph Stoner, a paleomagnetist at Oregon State University, said Thursday at an American Geophysical Union meeting.
Previous studies have shown that the strength of the Earth's magnetic shield has decreased 10 percent over the past 150 years. During the same period, the north magnetic pole wandered about 1,100km out into the Arctic, according to a new analysis by Stoner.
The rate of the magnetic pole's movement has increased in the last century compared to fairly steady movement in the previous four centuries, the Oregon researchers said.
At the present rate, the north magnetic pole could swing out of northern Canada into Siberia. If that happens, Alaska could lose its Northern Lights, which occur when charged particles streaming away from the sun interact with different gases in Earth's atmosphere.
The north magnetic pole was first discovered in 1831 and when it was revisited in 1904, explorers found that the pole had moved 50km.
For centuries, navigators using compasses had to learn to deal with the difference between magnetic and geographic north. A compass needle points to the north magnetic pole, not the geographic North Pole. For example, a compass reading of north in Oregon is about 170 east of geographic north.
In the study, Stoner examined the sediment record from several Arctic lakes. Since the sediments record the Earth's magnetic field at the time, scientists used carbon dating to track changes in the magnetic field.
They found that the north magnetic field shifted significantly in the last thousand years. It generally migrated between northern Canada and Siberia, but it sometimes moved in other directions, too.
On the Net:
American Geophysical Union: www.agu.org
April 28 to May 4 During the Japanese colonial era, a city’s “first” high school typically served Japanese students, while Taiwanese attended the “second” high school. Only in Taichung was this reversed. That’s because when Taichung First High School opened its doors on May 1, 1915 to serve Taiwanese students who were previously barred from secondary education, it was the only high school in town. Former principal Hideo Azukisawa threatened to quit when the government in 1922 attempted to transfer the “first” designation to a new local high school for Japanese students, leading to this unusual situation. Prior to the Taichung First
Chinese Nationalist Party (KMT) Chairman Eric Chu (朱立倫) hatched a bold plan to charge forward and seize the initiative when he held a protest in front of the Taipei City Prosecutors’ Office. Though risky, because illegal, its success would help tackle at least six problems facing both himself and the KMT. What he did not see coming was Taipei Mayor Chiang Wan-an (將萬安) tripping him up out of the gate. In spite of Chu being the most consequential and successful KMT chairman since the early 2010s — arguably saving the party from financial ruin and restoring its electoral viability —
The Ministry of Education last month proposed a nationwide ban on mobile devices in schools, aiming to curb concerns over student phone addiction. Under the revised regulation, which will take effect in August, teachers and schools will be required to collect mobile devices — including phones, laptops and wearables devices — for safekeeping during school hours, unless they are being used for educational purposes. For Chang Fong-ching (張鳳琴), the ban will have a positive impact. “It’s a good move,” says the professor in the department of
Article 2 of the Additional Articles of the Constitution of the Republic of China (中華民國憲法增修條文) stipulates that upon a vote of no confidence in the premier, the president can dissolve the legislature within 10 days. If the legislature is dissolved, a new legislative election must be held within 60 days, and the legislators’ terms will then be reckoned from that election. Two weeks ago Taipei Mayor Chiang Wan-an (蔣萬安) of the Chinese Nationalist Party (KMT) proposed that the legislature hold a vote of no confidence in the premier and dare the president to dissolve the legislature. The legislature is currently controlled
RSS