LEARNING OBJECTIVES

6.E.2 Understand the structure of the earth and how interactions of constructive and destructive forces have resulted in changes in the surface of the Earth over time and the effects of the lithosphere on humans.

6.E.2.1 Summarize the structure of the earth, including the layers, the mantle and core based on the relative position, composition and density.

6.E.2.2 Explain how crustal plates and ocean basins are formed, move and interact using earthquakes, heat flow and volcanoes to reflect forces within the earth

• EARTH -INTERACTIVE RESEARCH BOOKLET

• UNIT RESOURCES-Articles, animations, etc.

• UNIT REVIEW - 6.E.2.1 - 6.E.2.2

• REVIEW - Earth Composition and Boundary Collisions

• PLATE TECTONICS QUIZLET

6.E.2.3 Explain how the formation of soil is related to the parent rock type and the environment in which it develops.

6.E.2.4 Conclude that the good health of humans requires: monitoring the lithosphere, maintaining soil quality and stewardship.

UNIT RESOURCES

UNDERSTANDING CONCEPTS

STANDARDS EXPLAINED

6.E.2.1

The earth is composed primarily of rock

Three-fourths of the earth’s surface is covered by a relatively thin layer of water (some of it frozen), and the entire planet is surrounded by a relatively thin layer of gas we call the atmosphere

The Earth has a solid inner core that is surrounded by a liquid outer core. The inner core is a solid section of the Earth and is unattached to the mantle, being suspended by the molten outer core

The inner core is predominantly iron metal with significant amounts of the element nickel

This inner layer in mutual combination with the rotational motion of the Earth creates a dynamo effect where a force field is generated

This field is also known as Earth’s magnetic field

In terms of the physical aspects of the outer core, the layer is dense but not as dense as pure molten iron. Surrounding the entire dense, metallic core is a thick, hot, convective layer called the mantle

The crust consists of many continental and oceanic plates that have slowly moved and changed positions on the globe throughout geologic time.

6.E.2.2

The earth's plates sit on a dense, hot, somewhat melted layer of the earth

.The plates move very slowly, pressing against one another in some places and pulling apart in other places, sometimes scraping alongside each other as they do

.Mountains form as two continental plates, or an ocean plate and a continental plate, press together

.There are worldwide patterns to major geological events (such as earthquakes, volcanic eruptions, and mountain building) that coincide with plate boundaries. Lithospheric plates on the scale of continents and oceans constantly move at rates of centimeters per year as a result of movements in the mantle coupled with characteristics of the plates themselves

.Major geological events, such as earthquakes, volcanic eruptions, and mountain building, result from these plate motions

.The crustal plates range in thickness from a few to more than 100 kilometers

.Ocean floors are the tops of thin oceanic plates that spread outward from mid-ocean rift

zones; land surfaces are the tops of thicker, less dense continental plates

.Earth is made up of 4 different layers: inner core, outer core, mantle, crust

.Seismologists have studied how wave energy travels through the different layers of Earth

.Waves have characteristics: frequency, wavelength, amplitude and speed

.During an earthquake, energy is released into the Earth as: Primary waves, Secondary waves and Surface

waves.

6.E.2.3

Although weathered rock is the basic component of soil, the composition and texture of soil and its fertility and resistance to erosion are greatly

influenced by plant roots and debris, bacteria, fungi, worms, insects, rodents, and other organisms.

The upper-most layer of the continental crust is covered by soil.

The ingredients in soils can vary from place to place and around the Earth

.Different soils have many properties such as texture, particle size, pH, fertility and ability to hold moisture

.Depending upon the combination of properties, soils have great variability in their ability to support structures and plant growth

.Forces deep inside Earth and at the surface produce a slow cycle that builds, destroys, and changes the rocks in the crust

.Plate movements start the rock cycle by helping to form magma, the source of igneous rocks

.Plate movements also cause faulting, folding and other motions of the crust that help to form sedimentary and metamorphic rock

.Minerals form as hot magma cools inside the crust, or as lava hardens on the surface

.When these liquids cool to a solid state, they form crystals

.When elements and compounds that are dissolved in water leave a solution, crystallization of minerals occurs

.Soil is a mixture of: rock particles, minerals, decayed organic matter, water and air

.Soil forms as rock is broken down by weathering and mixes with other materials on the surface.

6.E.2.4

The environment may contain dangerous levels of substances that are harmful to human beings

.Therefore, the good health of individuals requires monitoring the soil, air, and water and taking steps to make these factors safe for all organisms. Evaluate ways in which human activities have affected Earth’s pedosphere and the measures taken to control the impact: vegetative cover, agriculture such

as (contour plowing, conservation plowing), land use, nutrient balance (crop rotation), soil as a vector

.Technology, such as remote sensing, has allowed

humans to better study the human impact on soil quality and erosion processes so that the soil can be protected and preserved

.Over time, remote sensing information can tell us how humans are constantly changing the surface of the Earth and what impact these changes are likely

to produce

.Technologies can also assist in finding ways to help prevent erosion

.It is important that humans be stewards of the pedosphere.