Download File

An Introduction to Ch 11&12
LAYERS OF THE EARTH!
Regions of the Earth
 The Earth is made up predominantly of two
major regions:
 A predominantly molten, central core
 A mostly solid outer mantle and crust
Hydrosphere and Crust
(0-35km)
 The crust is the top, solid surface layer of the
Earth
Quick Fact:
 The crust and the
upper mantle are
part of what we call
the Lithosphere! (the
solid portion of the
Earth)
 The Aesthenosphere
is the ductile – semiliquid/solid part of
the Earth located just
below the
Lithosphere.
 The Aesthenosphere
includes the upper
mantle.
Hydrosphere and Crust
(0-35km)
 The Hydrosphere contains




the bodies of water at or
near the surface, including:
Frozen surface water
Liquid surface water
Ground water
Water vapour
 All told the Earth’s water totals an estimated 336
million miles (~540 million kilometers), 97% of
which is contained in the oceans
Let’s Journey to The Center
of the Earth!
The Mantle: (35-2900km)
 The mantle is the semi-
solid layer directly below
the crust. It can itself be
broken into three distinct
parts:
 The Upper Mantle
(35- 670 km)
 The Transition Zone
(300- 700km)
 The Lower Mantle
(670- 2900km)
The Upper Mantle:
(35- 670 km)
 The contents of the upper mantle are not as
well defined as the crust and other layers. It
includes xenoliths, rocks that were shot
upward by explosive eruptions (some of
which contain diamonds)! Processes that take
place in the upper mantle have significant
impact at the crust, in the form of:
 Volcanic eruptions
 Earthquakes
 The introduction of some ores
The Transition Zone:
(300-700km)
 About 1/5th of the way through the mantle,
increases in pressure and temperature turn
many minerals into tightly packed crystals.
 This area is known as the transition zone
because it separates the lower mantle from the
upper mantle…
The Lower Mantle:
(670-2900km)
 The lower mantle comprises nearly 50
percent of the Earth’s Interior. Rather than
staying stagnant, the lower mantle convects
slowly creating superplumes, large rising jets
of partially molten rock.
The Outer Core:
(2900-5200km)
 The outer core consists of liquid metal that
flows turbulently . This creates a dynamo
which creates the Earth’s main geomagnetic
field on the Earth’s surface.
 The outer and inner cores generate so much
heat, about 4000 to 5000 Kelvin, which
contributes about one-fifth of the Earth’s
internal heat which ultimately flows to the
surface.
The Inner Core:
(5200-6371km)
 While most of the core is liquid, the inner core
is solid. It is believed to be metallic iron
although no studies have ever been
performed on the core.
Summary: