Homework for 12/18

1. What conditions might cause mud to flow?
A place with soil, water and a lot of movement.

2. What conclusion can you draw from the two images?
The piece of wood at 40 degrees is a lot easier to slide down because its a steeper slope

3. List at least two ways you could make the mud slide off the 30° slide plane without changing the plane's angle.
1- Add more water
2- Add vibration

4. What conditions in nature would be represented by the answers you gave for question 3?
Rain or Earthquakes

5. List at least two factors that contribute to the formation of mudflows on volcanoes.
1- The melting of snow caps
2- The gathering dust and ash from the eruption.

6. How might forest fires affect an area's potential for experiencing mudflows?
Because the ground is littered with debris from the fire and if mixed with water can turn into a mudflow with debris.

7. Hypothesize about how mudflows could change the topography of an area after a fire.
It could clear all of the debris and make it look like a fire was never there because everything would be buried.

8. What human activities strip soil of its protective vegetation and increase its vulnerability to mudflows?
Development of land and some kinds of farming.

9. Write a paragraph describing the conditions that cause dangerous mudflows. Include the types of locations where mudslides are most likely to occur.

Environments that have dangerous mudflows usually have a source of water, soil or debris, movement, a steep slope, and loose soil. All of those ingredients can combine to form a mudflow which is destructive and can ruin anything in its path. Volcanoes are a hot spot for where mudflows can happen because when the eruption occurs, the lava melts the ice caps and the ash combines with the water and forms a mud-like substance and goes down the mountain at highspeeds gathering debris along the way.

Mass Movement (Rock Fall)

Rock Fall is a type of mass movement. Rock fall occurs when blocks of rock shed from a cliff face and collect at the base.

Reading and Questions Set #3: pg. 202-204, question #1

1) A shield volcano is built of basaltic magma and it has a wide base and gently sloping sides. They can also be very big. A Cinder Cone is formed of pyroclastic material. They are the smallest types of volcanoes and they form in groups. They are different because a shield volcano can be very large and a cinder cone is very small. They are formed of different material, a cinder cone is formed of pyroclastic material and a shield volcano is formed of basaltic lava spreading slowly down the sides.

Reading and Questions Set #2: pg. 199-201, questions 1-3

1) They are different because they all have different viscosity, how explosive they are, and the different colors they have. Basaltic magma is found at oceanic hotspots and at mid ocean ridges, it has low viscosity and is a dark, dense rock.

2) Pahoehoe lava is smooth flowing, and cools into smooth rope-like shapes. AA lava is slow moving, and it cools into jagged shapes. Pillow lava erupts and cools underwater, it is very smooth when it cools.

3) Rhyolithic and Andesitic magma are associated with more explosive eruptions because they are the most explosive types of magma and they have the highest viscosity.Basaltic magma is associated with less explosive eruptions because it is the least explosive type of magma and it is the least viscosity.

Pages 194-197, Questions 1-3

1) Water in the subducted rock is released into the athenosphere, the water lowers the melting point, leading to the formation of magma. When the subducting plate melts, the magma gets less dense and rises.
2) At a hot spot, the magma is straight from the core, it pushed upward through the crust. It doesn't matter what kind of plate is at the boundary, because it rises in the middle of the plate. At the subduction boundary, the process of making magma is much different and the volcanoes at the subduction boundary have different magma than at hot spots.
3) At a divergent boundary, the plates split apart and magma is formed by the combination of low pressure and high temperature, then the magma is pushed up through the crust, and new crust is formed by the cooling magma.

Questions for plate boundries

1) Divergent boundaries -- where new crust is generated as the plates pull away from each other.
Convergent boundaries -- where crust is destroyed as one plate dives under another.
Transform boundaries -- where crust is neither produced nor destroyed as the plates slide horizontally past each other.
2) It means that plates are moving apart from each other. This happens because magma is pushing up from the mantle.
3) An example would be the Mid-Atlantic Ridge going through Iceland. The red triangles represent volcanoes in Iceland.
4) Where two plates move towards each other and collide.

5) a. oceanic-continental convergence


b. oceanic-oceanic convergence

c. Continental-continental convergence

6)
a. When an oceanic-continental convergence takes place, a deep trench on the floor of the ocean forms.
b. When an oceanic-oceanic convergence takes place, a deep trench on the floor of the ocean forms.
c. When a continental-continental convergence takes place, mountains are formed.
7) A transform boundary is when two plates are moving horizontally past each other and these boundaries usually cause small earthquakes or zig-zag plate margins an example in North America would be the San Andres fault zone in California.
8)
a. The Mid-Atlantic ridge is a divergent boundary with two oceanic plates
b. The Kuril Trench was made in a convergent boundary with two oceanic plates
c. The Philippines were formed in a convergent boundary with two oceanic plates. The Philippines are an island arc.
d. The East Africa Rift Valley was made in a divergent boundary, with two continental plates.
e. The Red Sea was a rift valley that got filled in with water. This means it formed a divergent boundary with two continental plates.
f. The Peru-Chile Trench is a convergent boundary with a continental and an oceanic plate.
g. The Aleutian Islands are an island arc, which means it was made by a convergent boundary with two oceanic plates.

Geologic Timeline Follow-up questions

1) On the Earth, you need oxygen, water and a source of food. Without those things, you would die because they are a necessity for life of a multi-celled organisms. That is why the Earth has "Goldilocks" conditions. Or perfect conditions for life to happen.
2) Archaeon Eon because that's when the Earth was born, oxygen started to fill the atmosphere, and the Earth's crust and oceans started to form. Those are all key events that led to the Earth being what it is today. Some of those are all also common ingredients for life to happen.
3) Not very significant at all because we haven't been here long enough to really change the pace of the Earth's development. However, we have managed to start to kill the atmosphere by polluting it with cars.

^This is an original remain fossil because the spider-like creature was trapped in the sap and then the sap became fossilized (amber), thus preserving the insides of the spider-like creature.
This is a replaced remains fossil because rock forming minerals attach to the hard part of the skeleton hardening them and then letting the soft parts decay. As you can tell here, the rock forming minerals attached to the outer layer of the fish.

3 is the youngest because it's the last layer deposited and according to the principle of superposition it is the youngest.

1 is the second youngest because it is the layer closest to the top with the intrusion,

6 is the third youngest because according to the principle of superposition, it is under the second youngest layer.

2 is the fourth youngest layer because it is an intrusion to the layers below 3,1,6.

5 is the fifth youngest layer because it is under the intrusion (2) and higher than layer 4.

4 is the oldest layer because it is under the intrusion (2) and lower than layer 5.