THE SOUTHWORTH PLANETARIUM
207-780-4249 www.usm.maine.edu/planet
<http://www.google.com/url?q=http%3A%2F%2Fwww.usm.maine.edu%2Fplanet&sa=D&sntz=1&usg=AFQjCNHulkHuLP13bOG2PkNrPazsGWFs2A>
70 Falmouth Street Portland, Maine 04103
43.6667° N 70.2667° W
Altitude: 10 feet below sea level
Founded January 1970
Julian Date: 2458857.16
2019-2020: LXXXII
"Meanwhile, back on Earth..."
THE DAILY ASTRONOMER
Wednesday, January 8, 2020
The Siberian Pole
[image: arctic-magnetic-declination_1200x480-noaa_0_0.png]
A September 2015 NOAA graphic pinpointing the magnetic pole almost at the
true geographic north pole. This once lethargic pole shifted position by
about 10 kilometers a year. Presently, its shift rate is about 40-50
kilometers an hour.
Yesterday we veered a bit far afield as we explored the most distant known
exoplanets. Today, we remain Earthbound: specifically at Earth's apex, in
the brutal north Polar region, where Earth's highly mobile and unseen
magnetic pole is moving out of the high Canadian north where it has
lingered for centuries and into northernmost Siberia. While the
consequences of this shift from North America to Asia remains, the
migration has captivated and even unsettled researchers who are confounded
by the pole's directional change and rapid motion.
We know that on June 1, 1831, an expedition lead by James Clark Ross
discovered the magnetic pole on the Boothia Peninsula around 72 degrees N
latitude. In 1903, the famed explorer Roald Amundsen located it a
different location, thereby demonstrating that the pole is mobile; it
shifts position due to alterations in Earth's core. Within Earth's
center one would find an ultra dense, incandescently hot iron-nickel core
surrounded by a molten outer core about 100 times larger in volume than the
Pacific Ocean. This core rotates at a slightly different rate than
Earth,itself. This rotational motion combined with the vast electrons
flows within the outer core behaves like a dynamo, generating the magnetic
field enclosing our planet. (Electricity and magnetism are two aspects
of a single fundamental force dubbed "electromagnetism.")
The magnetic pole was more lethargic in the past, traveling about 10 - 15
kilometers a year and following a generally northward trajectory. Within
the last decade, this shifting has accelerated, reaching an estimated speed
of slightly more than 50 kilometers a year. During the last ten years,
the pole has maneuvered out of Canada and toward Siberia, moving from the
western to eastern hemispheres. In September 2019, it was briefly aligned
with the actual geographic north pole (a highly uncommon occurrence) before
moving into Russia.
Earth's magnetic pole is a matter of grave importance to both humans and
the society they've developed. First, a vast magnetic field enshrouds our
planet, protecting us from the harsh radiation emitted by the Sun and more
distant cosmic objects. Secondly, the navigation systems on which so much
of our civilization depends is based on that field's strength and
orientation. Consequently, the field is mapped and the pole
location specified every five years with the World Magnetic Model produced
by the British Geological Survey in collaboration with national
environmental centers. The rapidity of the pole's motion induced them
to deviate from their five year publication schedule to produce an early
update in February 2019, representing only the second deviation in its
history.
Scientists don't have a complete picture of Earth's magnetic pole and so
are circumspect about offering any pronouncements about the magnetic
field's future. (Although, they have noted a gradual magnetic field
weakening, which could either be a precursor to a more dramatic event, such
as a field "flip," or it could be a regular cyclical diminishment.) They
know that the magnetic pole hasn't exhibited this much motion since records
began, providing enough of an impetus to scrutinize it more closely.
While GPS systems should not be affected by this west to east migration,
compasses could soon be directed east of north. Moreover, the farther away
from us the pole drifts, the less frequent aurora displays will become.
The closer one lives to the pole the more often one will tend to see the
Aurora Borealis, as the charged solar particles that excite the atmospheric
atoms to produce an aurora are drawn toward both the north magnetic pole.
Of course, as the Sun has been more quiescent than expected lately, the
aurora events might have been fewer and farther between, anyway.
Suffice it to say that we are not in any immediate danger; but in a world
of constant change, it is wise to be wary of a pole moving so quickly on a
planet that revolves through a neighborhood awash in harsh radiation.
To subscribe or unsubscribe from the "Daily Astronomer"
http://lists.maine.edu/cgi/wa?A0=DAILY-ASTRONOMER