Earth Science SOL Unit 8.4 - Mid-Ocean Ridges

Which TWO of the following are Earth's tectonic plates primarily composed of?

• Core

• Uppermost Mantle

• Lower Mantle

• Crust

Answer explanation

Earth's tectonic plates are primarily composed of the crust and the uppermost mantle. The crust is the outer layer, while the uppermost mantle is part of the lithosphere, which includes both layers.

Tags

NGSS.HS-ESS1-5

What is the point on Earth's surface directly above where an earthquake occurs called?

• Hypocenter

• Fault Line

• Epicenter

• Seismic Zone

Answer explanation

The point on Earth's surface directly above the earthquake's origin is called the epicenter. It is crucial for locating the earthquake's impact area, distinguishing it from the hypocenter, which is the actual point underground.

Tags

NGSS.MS-ESS3-2

What TWO of the following can a single plate be made of?

• Oceanic Lithosphere

• Continental Lithosphere

• Continental Exosphere

• Oceanic Hydrosphere

Answer explanation

A single tectonic plate can be composed of either Oceanic Lithosphere or Continental Lithosphere, as these are the two main types of lithosphere that make up the Earth's crust. The other options are not types of lithosphere.

Tags

NGSS.HS-ESS1-5

NGSS.HS-ESS2-1

What is the significance of mid-ocean ridges in plate tectonics?

• They are the highest mountains.

• They mark the edges of tectonic plates.

• They are the deepest parts of the ocean.

• They are unrelated to tectonic activity.

Answer explanation

Mid-ocean ridges are significant in plate tectonics as they mark the edges of tectonic plates where new oceanic crust is formed. This process is crucial for understanding plate movement and geological activity.

Tags

NGSS.HS-ESS1-5

NGSS.HS-ESS2-1

What is the primary difference between oceanic and continental lithosphere? Select TWO answers.

• Oceanic is thicker and older.

• Continental is thicker and older.

• Oceanic is thinner, younger, and denser.

• Continental is denser and younger.

Answer explanation

The continental lithosphere is thicker and older due to its formation processes, while the oceanic lithosphere is thinner, younger, and denser, formed at mid-ocean ridges and recycled into the mantle.

What is the significance of the Mid-Atlantic Ridge?

• It forms an ocean trench about the size of the Grand Canyon.

• It is the deepest part of the ocean.

• It is a volcanic island chain.

• It is a coral reef system.

Answer explanation

The Mid-Atlantic Ridge is significant as it is a divergent boundary where tectonic plates are moving apart, creating new oceanic crust, rather than forming an ocean trench. The correct choice is incorrect.

Tags

NGSS.HS-ESS1-5

NGSS.HS-ESS2-1

What is the relationship between seafloor spreading and ocean basin volume?

• Seafloor spreading increases ocean basin volume

• Seafloor spreading decreases ocean basin volume

• Seafloor spreading has no effect on ocean basin volume

• Seafloor spreading causes ocean basin volume to fluctuate

Answer explanation

Seafloor spreading occurs at mid-ocean ridges, where new oceanic crust is formed. This process increases the volume of the ocean basin as the newly created crust pushes older crust away, leading to a larger ocean basin overall.

What characterizes a Passive Plate Margin?

• It is a site of frequent earthquakes and volcanoes.

• It is a stable area with no tectonic activity.

• It is where a single tectonic plate transitions from the Oceanic Lithosphere to the Continental Lithosphere.

• It is a region where two continental plates collide.

Answer explanation

A Passive Plate Margin is characterized by the transition from Oceanic to Continental Lithosphere, indicating a stable area with less tectonic activity compared to active margins, which are sites of earthquakes and volcanoes.

Tags

NGSS.HS-ESS1-5

Where does the Oceanic Crust created by the Seafloor Spreading on the East Pacific Rise become part of?

• The Mid-Atlantic Ridge

• The Ring of Fire

• The North American Plate

• The Eurasian Plate

Answer explanation

The Oceanic Crust formed at the East Pacific Rise is part of the Ring of Fire, a region known for its tectonic activity, including earthquakes and volcanoes, due to the movement of tectonic plates in the Pacific Ocean.

Tags

NGSS.HS-ESS1-5

NGSS.HS-ESS2-1

What happens to the Oceanic Crust of the Mid-Atlantic Ridge?

• It becomes part of the Ring of Fire.

• It becomes part of the passive margin on the North American or Eurasian plate.

• It remains stationary.

• It subducts under the Pacific Plate.

Answer explanation

The Oceanic Crust at the Mid-Atlantic Ridge is formed by seafloor spreading and eventually becomes part of the passive margin on the North American or Eurasian plate as it moves away from the ridge.

Tags

NGSS.HS-ESS1-5

NGSS.HS-ESS2-1