Shaping Earth's Surface

Shaping Earth's Surface

Multiple Choice

A shaking of the ground that can damage both natural features and human-made structures

• fault

• earthquakes

• break of rocks

Multiple Choice

Earthquakes can occur at faults

• true

• false

Multiple Choice

What do you call a crack or a fracture in Earth's crust along which movement occurs?

• earthquake

• fault

• volcano

• rocks

Multiple Choice

A type of force that build up along faults causing the rocks on either side of the fault move and slide along the fault.

• magnetic

• convection

• gravity

• no force

Multiple Choice

Where do most earthquakes occur?

• ocean floor

• plate boundaries

• mantle

• core

Multiple Choice

Faults are smallest where one plate subducts into mantle.

• correct

• incorrect

Multiple Choice

The strongest and most damaging earthquakes occur when there is subduction of plate.

• true

• false

Volcanoes

The temperature of the Earth is high enough for rock to melt.

-are vents in Earth's crust through which molten rock flows.
-Do not form everywhere.

Volcanoes

Magma

molten rock stored beneath Earth's surface

Lava

magma that erupts onto Earth's surface

Where Volcanoes Occur

​Most volcanoes form at convergent boundaries

In some convergent boundaries, one plate subducts under another plate. Some rocks contain water within their structure. As the rocks subduct, heat and pressure drive the water out. This water can lower the melting temperature of the mantle

Where Volcanoes Occur

​Most volcanoes form at convergent boundaries

Magma then rises toward the surface and forms volcanoes on the plate that does not subduct. A line of volcanoes forms parallel to the plate boundary directly above the plate that subducted.
The volcanoes in Washington and Oregon, such as Mount Rainier, Mount St. Helens and Mount Hood, formed above the subducting Juan de Fuca Plate.

Multiple Choice

What is the first step that forms a volcano?

• the water lowers the melting point of the mantle and the mantle partially melts

• when two plates collide and one is subducted under the other

• magma will then rise

• water enters the mantle

Multiple Choice

What is the second step that forms a volcano?

• the water lowers the melting point of the mantle and the mantle partially melts

• when two plates collide and one is subducted under the other

• magma will then rise

• water enters the mantle

Multiple Choice

What is the third step that forms a volcano?

• the water lowers the melting point of the mantle and the mantle partially melts

• when two plates collide and one is subducted under the other

• magma will then rise

• water enters the mantle

Multiple Choice

What is the fourth step that forms a volcano?

• the water lowers the melting point of the mantle and the mantle partially melts

• when two plates collide and one is subducted under the other

• magma will then rise

• water enters the mantle

Multiple Choice

Where do volcanoes form?

• volcanoes forms parallel to the plate boundary above the plate that subducted

• volcanoes are form everywhere

• volcanoes are form only in the ocean

• volcanoes are form only in the mountains

How Volcanoes Change Earth's Surface

Volcanoes are some of Earth's most distinctive landforms.

Mountains can form over millions of years, but volcanoes can form in hundreds to thousands of years. Sometimes volcano formation happens even more quickly.

How Volcanoes Change Earth's Surface

Volcanoes erupt in two ways. Sometimes, lava can flow over Earth's surface before cooling, hardening, and becoming solid rock. This is called lava flow .

Lava flows can be more then 10 km long and over time can cover large areas surrounding a volcano.

How Volcanoes Change Earth's Surface

Volcanoes can erupt explosively. This kind of eruption can produce tiny pieces of glass made from solidified lava. These pieces are called ash and can be blown high into the atmosphere. When the ash falls back to Earth;s surface, it can cover vast areas.

Multiple Choice

Which forms quickly?

• Mountains

• Volcanoes

Multiple Choice

When volcanoes erupt silently producing a flow of lava, cools down, hardened and become solid rock, these flow is called

• lava flow

• rock flow

• cool rock

• lava

Multiple Choice

What is produce when volcanoes erupt explosively that blown high into the atmosphere?

• lava

• ash

• magma

• rock

Ocean Basins

Lava erupts from volcanoes on land.

However, not all lava flows on land. Recall that the land mases that make up North America and Europe began to separate when divergent boundary formed between them. What happened in the sea between these land masses as it became large?

Lava on the Ocean Floor

Lava erupts at both convergent plate boundaries and divergent plate boundaries. This lava hardens and forms new crust. At an oceanic divergent plate boundary, magma rises between two plates and forms new crust. As the plates move apart, more lava rises. The lava fills in the space and forms more ocean crust. The seafloor between North America and Europe is made of ocean crust that formed after the continents began to spread apart.

Mountains on the Ocean Floor

The ocean crust made at divergent plate boundaries is not flat.

Mid-ocean ridges are long, narrow mountains formed by magma at divergent boundaries.

Even though explosive volcanic eruptions usually occur near convergent plate boundaries, more lava erupts at divergent plate boundaries. Three-quarters of all lava erupts at mid-ocean ridges. As lava erupts under water, it hardens into flows and unique shapes, such as pillow lava.

Multiple Choice

Where do new ocean crust formed?

• oceanic divergent boundary

• continental divergent boundary

Multiple Choice

The ocean crust that are long, narrow mountains formed by magma at divergent boundaries are called

• mountains

• mid-ocean ridges

• volcanoes

• trench

Multiple Choice

Explosive volcanic eruptions usually occur near convergent boundaries but more lava erupts at divergent plate boundaries.

• true

• false

Match

Identify the type of plate movement for each formation of landforms

• Volcanoes form

• Features that cross the fault, such as streams, can shift

• Tall mountains form

• Valleys and mid-ocean ridges form

convergent boundary with subduction

transform boundary

convergent boundary without subduction

divergent boundary

• convergent boundary with subduction

• transform boundary

• convergent boundary without subduction

• divergent boundary