At least we are now getting detailed information regarding the
magnetic field.
The usual model for field generation is essentially not possible and
can be dismissed out of hand. A more likely model posits an active
conductive layer deep in the crust in which magnetic fields wax and
wane and that is what the observers are seeing generally.
Such would still produce a north south orientation with poor
stability which is what we are certainly seeing. It would also be
much more easily affected by external fields as well.
Satellite Swarm
Spots North Pole Drift
Jun 22, 2014 03:33 AM
ET by Jason Major
Swarm measurements of
Earth’s magnetic field from June 2014. Blue areas show where it has
weakened.
http://news.discovery.com/earth/satellite-swarm-spots-north-pole-drift-140622.htm
The North Pole is
moving. Not the geographic axis around which Earth spins, of course,
but rather its magnetic pole, the north end of which is
slowly but steadily wandering across the Arctic Ocean toward Siberia.
Scientists have known about our planet’s shifting magnetic field
for a long time, since at least 1904 — and today we now have a
“Swarm” of satellites investigating its many inconsistencies from
orbit.
Launched in November
2013, ESA’s Swarm mission consists of three 9-meter satellites
orbiting the planet at altitudes of 300-530 km (186-330 miles). Their
goal is to monitor Earth’s dynamic magnetic field, observing its
changes over a period of four years.
The data gathered by
the Swarm satellites will help scientists better understand how our
magnetic field works, how it’s influenced by solar activity, and
why large parts of it are found to be weakening.
Because the magnetic
field is our planet’s first line of defense against radiation from
both the sun and deep space, understanding what makes it tick is very
important.
The first
high-definition measurements from Swarm have been made and what’s
become apparent are weakening regions within the core-generated
magnetic field over the western hemisphere, while parts of the
southern Indian Ocean show strengthening fields.
Swarm measurements
also confirm the march of the magnetic north pole toward Russia.
“These initial
results demonstrate the excellent performance of Swarm,” said Rune
Floberghagen, ESA’s Swarm Mission Manager. “With unprecedented
resolution, the data also exhibit Swarm’s capability to map
fine-scale features of the magnetic field.”
Watch a video of the
Swarm compass findings below:
It’s known that
Earth’s magnetic poles occasionally reverse, a process that takes
several thousand years to complete and creates a much more complex
and unpredictable — but still protective — field during the
interim. And while the weakening observed by Swarm could be a sign of
a polarity reversal on the way, it’s an event that’s probably
still thousands of years away.
Meanwhile, missions
like Swarm will allow us to better understand the magnetic field we
have today, in order to understand what it will do in the future.
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