Earth's magnetic
north pole
has shifted away
from Canada,
and moved closer
to Siberia,
at a rapid pace
in recent years.
Magnetic north pole
has shifted over time,
since scientists first
identified its location
in 1831.
James Clark Ross
first identified it on
the Boothia Peninsula
in Canada's Nunavut
territory, in 1831,
Scientists have been
carefully measuring
its location ever since.
Researchers believe
two massive blobs
of molten iron
in Earth's outer core
may have spurred
the runaway
magnetic pole.
Researchers from U.K.
and Denmark now say
they've uncovered
the reason for this
mysterious movement:
Two writhing lobes
of magnetic force
are duking it out
near Earth's core.
"The wandering of Earth’s
north magnetic pole,
the location where
the magnetic field
points vertically
downwards,
has long been
a topic of scientific
fascination,"
researchers
write in the
May 5 2020
issue of Nature
Geoscience.
Livermore et al.
Nature Geoscience (2020)
Earth's magnetic field
is generated by molten
iron in its outer core.
The flow
of this
liquid iron
can influence
the location of
of the planet's
magnetic poles.
The poles
have drifted,
and even
swapped places
many times,
over Earth's
long history.
What's different
about the recent shift
is how quickly it has
been happening.
From 1999 to 2005,
Earth's magnetic
north pole went
from shifting
up to 9 miles
each year,
to as much
as 37 miles
in a year.
Scientists
studied over
20 years
of satellite
data from the
European Space
Administration's
Swarm satellite
mission, and
discovered that
"...over the
last two decades
the position
of the north
magnetic pole
has been
largely determined
by two large-scale
lobes of negative
magnetic flux
on the core–mantle
boundary under
Canada and Siberia,"
according to the study.
Between
1970 and 1999,
the flow of molten,
magnetic material
in Earth's outer core
changed.
Because of
the change,
researchers say
the magnetic blob
beneath Canada
slowly elongated,
weakening the
corresponding
magnetic intensity
on Earth's surface.
Eventually, the blob
of molten material
beneath Canada
split in two, and
the stronger one
slowly shifted
toward the blob
beneath Siberia.
This spurred
the magnetic
north pole
to move
closer
and closer
to Siberia,
where the
magnetic
intensity
was stronger.
In 2017, the magnetic
north pole fell within
240 miles of the
geographic north pole.
The movement
has been so rapid
that the British
Geological Survey,
and U.S. National
Geophysical
Data Center,
who update
the World's
Magnetic Model,
have had to
accelerate
their process
to keep up.
The scientists
generate
a series
of models of
Earth's core
in an effort
to understand
how it might
move in the
future.
"Our predictions
are that the pole
will continue
to move
towards Siberia,
but forecasting
the future
is challenging
and we
cannot be sure,"
the study's
lead author,
geophysicist
Phil Livermore
of the University
of Leeds, told
Live Science.
These shifts have
major consequences
for global navigation
systems —
from ships at sea,
to our smart phones
-- all impacted
by this magnetic
movement.