This document discusses the layers of the Earth and the internal and external processes that affect it. It describes the four major layers - the core, mantle, crust, and lithosphere. The core is divided into a solid inner core and liquid outer core. The mantle is divided into upper and lower sections with an asthenosphere in between. The crust consists of thicker continental crust and thinner oceanic crust. Both internal processes like tectonics and volcanism in the mantle and core, and external processes like weathering and erosion powered by the sun impact the Earth's surface and shape its features over time.

1. The dynamic planet
• There are processes(systems) that occur under the earth’s surface
• An Endogenic system encompasses internal processes that
produce flows of heat and material from deep below Earth’s crust.
o This includes Tectonics, Earthquakes, and Volcanism.
• An Exogenic system involves external processes that set into
motion air, water, and ice, all powered by solar energy
o This includes Rivers, Landforms, Weathering, Erosion, Oceans,
Glaciers.

2. Earth’s interior
• The earth is made up of four layer which are:
oThe core
oMantle
oCrust
figure 1.1 layers of the earth

3. The core as the center of the earth.
–Core
•Inner core
•Outer core
•Gutenberg discontinuity
•Inner core is solid.
•Outer core is liquid.
•Core mass = 1/3 of Earth’s mass.
•Core volume = 1/6 of Earth’s volume. figure1.2 layers of the earth
The core and the mantle are separated by the Gutenberg discontinuity

4. Earth’s mantle
• The mantle is divided into two parts
• Lower mantle
• Upper mantle
• asthenosphere
o Lower mantle and Upper mantle
o Average depth is about 2900 km.
o Consists of 80% Earth’s total volume figure 1.3 mantle structure
o Average density is 4.5g/cm3.

5. Earth’s mantle
• Betweenthe upper mantle and the uppermost mantle, there is a plastic-
like layer called the asthenosphere.
• A plastic layer will slowly flow when a force is present. A rigid layer will not
flow when a force acts on it; instead it will bend or break.
• The boundary between the uppermost mantle and the crust above is called
the Mohorovicicdiscontinuity, or Moho.
Figure 1.4 MOHO discontinuity

6. crust
• Lithosphere consists of the continental crust and the oceanic .
• Continental crust is the relatively thick part of the earth's crust which forms
the large land masses. It is generally older and more complex than the
oceanic crust.
• Oceanic crust is the uppermost layer of the oceanic portion of a
tectonic plate. It is composed of the upper oceanic crust, with
pillow lavas and a dike complex, and the lower oceanic crust,
composed of troctolite, gabbro and ultramafic cumulates
Figure 1.5 the lithosphere

7. References
Earths CrustKids Fun ScienceContinental and oceanic crust, USGS(accessed 02 septemeber 2018 )
Oceanic crust |geology | Britannica.com
https://www.britannica.com/science/oceanic-crust (accessed 02 September 2018)
The Earth's Layers Lesson #1 | Volcano World | Oregon State University
volcano.oregonstate.edu/earths-layers-lesson-1(accessed 02 September 2018)
QUICK REVIEW… Layers of the Earth - ppt video online downloadSlidePlayerLayers of the
Earth:https://slideplayer.com/slide/9197507/ (accessed 03 September 2018)
Interior of the Earth: Crust, Mantle and Core - Clear IASClearIASCONRAD and MOHO
discontinuities:
https://www.google.co.za/search?q=moho+discontinuity&source=lnms&tbm=isch&sa=X&ved=0ahUK
EwjPuID3_p7dAhXqCcAKHZ4OBHQQ_AUICigB&biw=1366&bih=662#imgrc=vYeP4FFU5WOHUM:
(accessed 02 September 2018)
Earth's Interior - 2018 News and Scientific Articles on Live Science
https://www.livescience.com/topics/earth-s-interior (accessed 03 septemeber 2018)