Jump to content

Earth's magnetic field


desdemona

Recommended Posts

Tuesday, July 13, 2004

Earth's magnetic field is collapsing, scientists say

Change will wreak havoc -- but not for about 2,000 years

By WILLIAM J. BROAD

THE NEW YORK TIMES

The collapse of the Earth's magnetic field, which both guards the planet and guides many of its creatures, appears to have started in earnest about 150 years ago. The field's strength has waned 10 percent to 15 percent so far and this deterioration has accelerated lately, increasing debate over whether it portends a reversal of the lines of magnetic force that normally envelop the Earth.

During a reversal, the main field weakens, almost vanishes, and then reappears with opposite polarity. Afterward, compass needles that normally point north would point south, and during the thousands of years of transition, much in the heavens and Earth would go askew.

A reversal could knock out power grids, hurt astronauts and satellites, widen atmospheric ozone holes, send polar auroras flashing to the equator and confuse birds, fish and migratory animals that rely on the steadiness of the magnetic field as a navigation aid. But experts said the repercussions would fall short of catastrophic, despite a few proclamations of doom and sketchy evidence of past links between field reversals and species extinctions.

Although a total flip may be hundreds or thousands of years away, the rapid decline in magnetic strength is already damaging satellites.

Last month, the European Space Agency approved the world's largest effort at tracking the field's shifts. A trio of new satellites, called Swarm, is to monitor the collapsing field with far greater precision than before and help scientists forecast its prospective state.

"We want to get some idea of how this would evolve in the near future, just like people trying to predict the weather," said Gauthier Hulot, a French geophysicist working on the satellite plan. "I'm personally quite convinced we should be able to work out the first predictions by the end of the mission."

The discipline is one of a number -- such as high-energy physics and aspects of space science -- in which Europeans recently have come from behind to seize the initiative, dismaying some American experts.

read the entire article here:

http://seattlepi.nwsource.com/national/181...agnetism13.html

Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Our picks

    • Wait, Burning Man is going online-only? What does that even look like?
      You could have been forgiven for missing the announcement that actual physical Burning Man has been canceled for this year, if not next. Firstly, the nonprofit Burning Man organization, known affectionately to insiders as the Borg, posted it after 5 p.m. PT Friday. That, even in the COVID-19 era, is the traditional time to push out news when you don't want much media attention. 
      But secondly, you may have missed its cancellation because the Borg is being careful not to use the C-word. The announcement was neutrally titled "The Burning Man Multiverse in 2020." Even as it offers refunds to early ticket buyers, considers layoffs and other belt-tightening measures, and can't even commit to a physical event in 2021, the Borg is making lemonade by focusing on an online-only version of Black Rock City this coming August.    Read more...
      More about Burning Man, Tech, Web Culture, and Live EventsView the full article
      • 0 replies
    • Post in What Are You Listening To?
      Post in What Are You Listening To?
    • Post in What Are You Listening To?
      Post in What Are You Listening To?
    • Post in What Are You Listening To?
      Post in What Are You Listening To?
    • Post in What Are You Listening To?
      Post in What Are You Listening To?
×
×
  • Create New...