The Shifting Position Of The North Magnetic Pole Since 1590 – Brilliant Maps

The
map
above
shows
how
much
the
North
Magnetic
pole
has
shifted
between
1590
and
today.

From
the
map’s
author:

Positions
of
North
Magnetic
Pole
of
the
Earth.

Poles
shown
are
dip
poles,
defined
as
positions
where
the
direction
of
the
magnetic
field
is
vertical.

Red
circles
mark
magnetic
north
pole
positions
as
determined
by
direct
observation,
blue
circles
mark
positions
modelled
using
the
GUFM
model
(1590–1890)
and
the
IGRF-12
model
(1900–2020)
in
1
year
increments.

For
the
years
1890–1900,
a
smooth
interpolation
between
the
two
models
was
performed.
The
modelled
locations
after
2015
are
projections.

Why
and
How
the
Earth’s
North
Magnetic
Pole
Shift

The
Geodynamo
in
the
Outer
Core

• 
  Molten
  outer
  core:
  Earth’s
  magnetic
  field
  originates
  primarily
  in
  its
  liquid
  iron–nickel
  outer
  core.
  Convection
  currents
  in
  the
  molten
  metal,
  combined
  with
  Earth’s
  rotation,
  create
  electric
  currents.
  These
  currents
  generate
  a
  magnetic
  field
  through
  what
  is
  called
  the
  
  geodynamo.
• 
  Constant
  flux:
  Because
  the
  flow
  patterns
  in
  the
  outer
  core
  are
  dynamic
  (like
  weather
  patterns
  on
  Earth’s
  surface,
  but
  on
  geologic
  timescales),
  the
  magnetic
  field
  is
  never
  entirely
  static.
  This
  leads
  to
  gradual
  
  “secular
  variation”,
  or
  drift,
  in
  the
  field
  configuration.
• 
  Pole
  wandering:
  The
  magnetic
  poles
  are
  where
  field
  lines
  are
  most
  strongly
  vertical.
  As
  the
  magnetic
  field
  changes,
  these
  “verticality”
  points
  move.
  The
  
  North
  Magnetic
  Pole
  has
  therefore
  been
  wandering
  across
  the
  Arctic.

Rate
of
Drift

• Over
  the
  last
  century
  and
  a
  half,
  the
  
  speed
  of
  the
  North
  Magnetic
  Pole’s
  motion
  has
  varied
  significantly.
• In
  the
  early
  20th
  century,
  it
  moved
  roughly
  
  10
  km
  per
  year.
• Around
  the
  late
  20th
  century
  and
  early
  21st
  century,
  measurements
  indicated
  the
  drift
  speed
  increased
  to
  over
  
  50
  km
  per
  year.
• Recently,
  there
  have
  been
  indications
  that
  the
  speed
  may
  have
  slowed
  somewhat
  again,
  but
  the
  pole
  still
  continues
  to
  move
  in
  the
  general
  direction
  of
  Siberia.

A
Brief
History
of
North
Magnetic
Pole
Observations

1. 
   James
   Clark
   Ross
   (1831):
   The
   
   British
   explorer
   who
   made
   one
   of
   the
   first
   well-documented
   discoveries
   of
   the
   approximate
   location
   of
   the
   North
   Magnetic
   Pole
   on
   the
   Boothia
   Peninsula
   in
   Canada.
2. 
   Later
   Arctic
   Explorers
   (late
   19th–early
   20th
   centuries):
   Explorers
   like
   
   Roald
   Amundsen
   confirmed
   that
   the
   pole
   was
   no
   longer
   exactly
   where
   Ross
   first
   found
   it,
   noting
   a
   shift
   of
   tens
   of
   kilometers
   over
   the
   decades.
3. 
   Modern
   Measurements
   (Mid-20th
   century
   to
   Present):
   Satellite
   technology
   (like
   the
   European
   Space
   Agency’s
   Swarm
   mission)
   and
   global
   observation
   networks
   give
   us
   real-time
   tracking
   of
   the
   magnetic
   field.
   They
   have
   documented
   the
   significant
   acceleration
   in
   the
   pole’s
   drift
   rate
   in
   recent
   decades.

The
Carrington
Event
(1859)
and
Geomagnetic
Storms

The
Solar
Superstorm

• 
  What
  Happened:
  On
  September
  1–2,
  1859,
  astronomer
  Richard
  Carrington
  observed
  an
  intense
  white-light
  solar
  flare
  on
  the
  Sun.
  The
  associated
  coronal
  mass
  ejection
  (CME)
  hit
  Earth
  roughly
  17
  hours
  later,
  causing
  the
  
  
  Carrington
  Event,
  the
  largest
  recorded
  geomagnetic
  storm
  in
  history.
• 
  Effects
  on
  Earth:
  Telegraph
  systems
  across
  North
  America
  and
  Europe
  failed
  or
  caught
  fire;
  auroras
  were
  seen
  as
  far
  south
  as
  the
  Caribbean.
• 
  Relevance
  to
  Pole
  Shift:
  Solar
  storms
  and
  CMEs
  can
  
  temporarily
  disturb
  Earth’s
  magnetic
  field,
  creating
  geomagnetic
  storms.
  However,
  
  long-term
  pole
  shifts
  are
  tied
  more
  to
  core
  fluid
  dynamics
  (the
  geodynamo)
  than
  to
  external
  solar
  activity.
  Events
  like
  the
  Carrington
  superstorm
  can
  produce
  
  short-lived
  perturbations
  but
  do
  not
  directly
  cause
  the
  slow
  secular
  drift
  of
  the
  poles.

Geomagnetic
Reversal:
History
and
Mechanism

What
Is
a
Geomagnetic
Reversal?

A

geomagnetic
reversal
occurs
when
the

North
and
South
Magnetic
Poles
effectively
swap
positions.

In
the
rock
record,
this
can
be
seen
as
a
flip
in
the
orientation
of
magnetic
minerals,
which
align
with
Earth’s
ambient
magnetic
field
at
the
time
of
their
formation.

Historical
Record

• 
  Brunhes–Matuyama
  Reversal
  (~780,000
  years
  ago):
  The
  
  most
  recent
  major,
  well-confirmed
  reversal
  in
  Earth’s
  geological
  record.
• 
  Frequency:
  Over
  the
  past
  20
  million
  years,
  reversals
  have
  occurred
  on
  average
  every
  200,000
  to
  300,000
  years,
  but
  the
  timing
  is
  irregular
  and
  can
  vary
  greatly.
• 
  Multiple
  Reversals:
  Analysis
  of
  ocean
  floor
  basalts
  (especially
  along
  mid-ocean
  ridges)
  has
  revealed
  a
  “barcode”
  pattern
  of
  magnetic
  stripes.
  These
  stripes
  reflect
  past
  reversals
  as
  new
  crust
  is
  created
  at
  the
  ridges
  and
  locked
  in
  the
  prevailing
  magnetic
  polarity.

Timescale
and
Process

• 
  Gradual
  Flip:
  Contrary
  to
  the
  idea
  of
  an
  “overnight
  flip,”
  reversals
  often
  unfold
  over
  thousands
  of
  years.
  During
  these
  transitions,
  the
  magnetic
  field
  can
  become
  weaker
  and
  more
  complex,
  with
  multiple
  “north”
  and
  “south”
  poles
  possibly
  appearing
  in
  different
  locations.
• 
  Field
  Strength
  Decline:
  Some
  measurements
  suggest
  Earth’s
  overall
  magnetic
  field
  strength
  has
  
  decreased
  by
  around
  10-15%
  in
  the
  last
  150–200
  years,
  prompting
  speculation
  about
  whether
  a
  reversal
  might
  be
  “due.”
  However,
  the
  field
  has
  weakened
  and
  recovered
  many
  times
  in
  the
  past
  without
  a
  complete
  reversal.

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Author: Brilliant Maps