Some mountains move. (Lesson 1)
Mountains can get taller. (Lesson 1)
Mt. Everest is growing over time. (Lesson 1)
Mountains can also shrink. (Lesson 1)
The ground moves back and forth in an earthquake. (Lesson 2)
Some parts of the surface crack open with a noticeable difference in between the ground on either side of the crack after an earthquake. (Lesson 2)
Earthquakes exist on or near almost all mountain ranges. (Lesson 2)
There seems to be a correlation between when mountains were highest or growing and where the earthquakes are the largest or most frequent. (Lesson 2)
While earthquakes seem to be correlated to changes in elevation, we are not sure what is occurring under the surface. (Lesson 2)
The surface is often covered with sediment (broken rock, dirt, gravel, sand). (Lesson 3)
Sediment and solid rock make up Earth’s surface. (Lesson 3)
Rocks have different properties, including density and melting point. (Lesson 3)
Everywhere we look, solid rock, known as bedrock, is found on, near, or below the surface of Earth. (Lesson 3)
Everywhere we look, solid rock, known as bedrock, is found on, near, or below the surface of Earth. (Lesson 3)
The characteristics of rocks change the deeper underground they are. (Lesson 3)
As we move deeper underground, temperature increases and rocks are more compressed. (Lesson 3)
As rocks become hotter and more compressed, their behavior changes - they changes state, and tend to begin to move and shift (creep). (Lesson 3)
The rock deep below the ocean bottom is more dense than the rock deep below the continents. (Lesson 3)
Sections of bedrock in between these fault lines of cracks from earthquakes are called plates. (Lesson 4)
The cracks must go really far down into and through the bedrock to where the rock begins to creep, shift, and move. (Lesson 4)
There is evidence of at least two really large and long crack lines on either side of most of the United States. (Lesson 4)
There are other plates in the world that can be found in between long lines of fault lines. (Lesson 4)
All plates are constantly moving in different directions and at different speeds. (Lesson 5)
Plates move because they sit on top of deeper, warmer rock layers which move, or creep. (Lesson 5)
When creep occurs, mountains and all other features on the plate above also move. (Lesson 5)
When plates move towards each other, they collide and mountains can get taller. (Lesson 6)
Plates can move next to each other in opposite directions. (Lesson 6)
Plate boundaries or edges are rough; when plates interact, they can get stuck against or slip against each other, which we can feel as earthquakes. (Lesson 6)
Plate movement causes earthquakes. (Lesson 6)
Plate movement can cause mountains to get taller. (Lesson 6)
Volcanoes occur in some of the same places where earthquakes occur. (Lesson 7)
Volcanoes occur in lines where an oceanic plate collides with a continental plate. (Lesson 7)
When a more dense oceanic plate collides with a less dense continental plate, the oceanic plate moves under the continental plate. (Lesson 7)
The portion of the oceanic plate that moves below the continental plate begins to heat up, causing the bedrock and sediments to melt and the water in the sediments to boil. (Lesson 7)
The melted earth materials and steam move upward through openings called volcanoes, in the continental plate. (Lesson 7)
Volcanic eruptions can cause mountains to grow in height when new earth material is added, or shrink when existing earth material is scattered. (Lesson 7)
Plates are moving apart along the Mid-Atlantic Ridge. (Lesson 8)
Scientist call the place where two plates are moving apart a ridge. (Lesson 8)
Magma from the mantle is pushing up from under the plate, which can be seen in places like volcanoes and fissures in Iceland and along ridges. (Lesson 8)
New oceanic plate material is being formed at ridges. (Lesson 8)
The pushing of magma on the plates causes the plates to move, which causes changes to mountains elevations and location over time. (Lesson 8)
Plate movement causes changes to mountains. (Lesson 9)
There are a sequence of events that occur to cause changes to a mountain. (Lesson 9)
This sequence involves magma moving and pressing on the crust, which makes the plates move. This plate movement results in changes to the surface of Earth, including changes to mountain height and location. (Lesson 9)
Oceanic plates that were created over time were not always in existence. (Lesson 10)
Average rates of plate movement and plate direction can be used to determine where plates were once located. (Lesson 10)
Small changes to the distance between continents can add up to larger visible changes seen from a larger scale. (Lesson 10)
Older rock and associated fossils can be found under younger rock and fossils. (Lesson 10)
To support that two land masses were once together, patterns in data across the two land masses need to be similar or the same. (Lesson 10)
Data from rock strata, fossils, and other changes in land support that the African and South American continents were once together at the Mid-Atlantic Ridge. (Lesson 10)
All major continents were once touching and formed a large single landmass that existed hundreds of million of years ago. (Lesson 11)
Multiple sources of data are needed to determine where plates were located in the past. (Lesson 11)
The Appalachian Mountains, formed 470 million years ago, and the Ural Mountains, formed more than 300 million years ago, were both created in the same way that other mountains were formed--through plate collisions. (Lesson 12)
Plate interactions cannot explain why the Appalachians are decreasing in elevation or why the Ural Mountains are neither increasing or decreasing in elevation. (Lesson 12)
Erosion rates are a representation of how much an area of land is worn down by all the erosive processes together. (Lesson 13)
Uplift rates are a representation of how much the land is being pushed up from below by plate movements. (Lesson 13)
The relationship between the erosion rates above the surface and the uplift rates below the surface determine the elevation above sea level. 1) Erosion rates that are higher than uplift rates result in land decreasing in elevation, 2) erosion rates that are less than uplift rates result in land increasing in elevation, and 3) erosion rates that are equal to uplift rates results in no change in elevation. (Lesson 13)
Tectonic plate movement has caused uplift to occur at mountains, pushing up rocks that used to exist on ancient seafloors. (Lesson 14)
Over time, marine fossils from the ancient seafloor are exposed due to erosional processes. (Lesson 14)
Erosional processes will always be occurring and will continue to erode the landscape into the distant future. (Lesson 14)