59
© Springer Nature Switzerland AG 2020
A. Kerényi, R. W. McIntosh, Sustainable Development in Changing Complex Earth Systems,
Sustainable Development Goals Series, https://doi.org/10.1007/978-3-030-21645-0_3
Internal Material Flows
in the Earth and Their Effects
on the Society
3.1
Material Flow in the Outer
Core of Earth
The material of the inner core of Earth is composed of (or behaves like) iron in more than 95%
and—despite high temperature—it is solid due
to the extreme pressure prevailing in it.
Therefore, no material flow can be presumed in
the inner core.
Iron also dominates in the outer core, however, in somewhat smaller ratio (more than 90%).
The main difference to the inner core is that the
viscosity of the outer core is very small, it is practically liquid and intense convection currents can
be detected in it. These currents cause the “geodynamo” phenomenon resulting in a magnetic
field around the Earth (Lowrie 2007). Magnetic
minerals of the crust and the upper mantle also
contribute to this magnetic field.
The geomagnetic field (magnetosphere) is a
magnetic field that changes both in space and
time: numerous changes can be observed in it
from regular daily patterns to magnetic storms.
Pattern of the magnetic field is symmetric near
the Earth, but they are distorted as distance from
the planet increases (Fig. 3.1). This distortion is
caused by solar wind (flow of particles from the
Sun) of variable intensity. Magnetosphere
extends to 6–8 times the radius of Earth on the
sunward side while the field lines on the opposite
side open up and the magnetic field could extend
up to 1000 times the radius of the Earth. (It has to
be noted though that magnetic field lines running
close to the surface of the Earth are much more
entangled than shown in Fig. 3.1 due to the modifying effects of the magnetic conditions of certain minerals in the Earth’s crust. This is
simulated well in the work of Williams (2015).
This fact, however, causes no change whatsoever, in the basically beneficial function of the
magnetosphere.)
The magnetosphere can be regarded the first
line of defence for life on Earth (including
human beings). Since it diverts the charged particles of the solar wind it protects the majority of
the surface of Earth from them causing, at the
same time, polar lights (aurora) at the magnetic
poles of the planet. Solar winds of variable
intensity cause magnetic storms every now and
then. In such cases, a part of the particles arriving from the Sun get into the inside of the magnetosphere mixing with the plasma formed there.
The horizontal component of the field intensity
decreases significantly causing disturbances in
telecommunication and the operation of the
devices of satellites.
Based on palaeomagnetic studies, the magnetic poles of our planet are known to change
places over irregular time periods. This is called
pole reversal. Such reversal is preceded by the
ever-extending weakening of the magnetic field
experienced locally initially and then extending
3
© Springer Nature Switzerland AG 2020
A. Kerényi, R. W. McIntosh, Sustainable Development in Changing Complex Earth Systems,
Sustainable Development Goals Series, https://doi.org/10.1007/978-3-030-21645-0_3
Internal Material Flows
in the Earth and Their Effects
on the Society
3.1
Material Flow in the Outer
Core of Earth
The material of the inner core of Earth is composed of (or behaves like) iron in more than 95%
and—despite high temperature—it is solid due
to the extreme pressure prevailing in it.
Therefore, no material flow can be presumed in
the inner core.
Iron also dominates in the outer core, however, in somewhat smaller ratio (more than 90%).
The main difference to the inner core is that the
viscosity of the outer core is very small, it is practically liquid and intense convection currents can
be detected in it. These currents cause the “geodynamo” phenomenon resulting in a magnetic
field around the Earth (Lowrie 2007). Magnetic
minerals of the crust and the upper mantle also
contribute to this magnetic field.
The geomagnetic field (magnetosphere) is a
magnetic field that changes both in space and
time: numerous changes can be observed in it
from regular daily patterns to magnetic storms.
Pattern of the magnetic field is symmetric near
the Earth, but they are distorted as distance from
the planet increases (Fig. 3.1). This distortion is
caused by solar wind (flow of particles from the
Sun) of variable intensity. Magnetosphere
extends to 6–8 times the radius of Earth on the
sunward side while the field lines on the opposite
side open up and the magnetic field could extend
up to 1000 times the radius of the Earth. (It has to
be noted though that magnetic field lines running
close to the surface of the Earth are much more
entangled than shown in Fig. 3.1 due to the modifying effects of the magnetic conditions of certain minerals in the Earth’s crust. This is
simulated well in the work of Williams (2015).
This fact, however, causes no change whatsoever, in the basically beneficial function of the
magnetosphere.)
The magnetosphere can be regarded the first
line of defence for life on Earth (including
human beings). Since it diverts the charged particles of the solar wind it protects the majority of
the surface of Earth from them causing, at the
same time, polar lights (aurora) at the magnetic
poles of the planet. Solar winds of variable
intensity cause magnetic storms every now and
then. In such cases, a part of the particles arriving from the Sun get into the inside of the magnetosphere mixing with the plasma formed there.
The horizontal component of the field intensity
decreases significantly causing disturbances in
telecommunication and the operation of the
devices of satellites.
Based on palaeomagnetic studies, the magnetic poles of our planet are known to change
places over irregular time periods. This is called
pole reversal. Such reversal is preceded by the
ever-extending weakening of the magnetic field
experienced locally initially and then extending
3