Geologic Breakthrough (1-2) Review

What is the process by which new oceanic crust forms along a mid-ocean ridge and older crust moves away from the ridge?

• Seafloor spreading

• Continental drift

• Plate tectonics

Answer explanation

Seafloor spreading is the process where new oceanic crust forms at mid-ocean ridges as tectonic plates pull apart, causing older crust to move away from the ridge. This is a key mechanism in plate tectonics.

Tags

NGSS.MS-ESS2-3

What evidence did Wegener use to support the idea of continents moving?

• Rock formations, climate, fossils

• Volcanoes, earthquakes, tsunamis

• Ocean currents, wind patterns, tides

Answer explanation

Wegener supported his theory of continental drift with evidence from rock formations that matched across continents, similar fossil records found in different regions, and climate indicators like glacial deposits in now-tropical areas.

Tags

NGSS.MS-ESS2-3

NGSS.MS-LS4-1

Why was Wegener's idea not accepted by scientists of his day?

• He did not offer an explanation of the mechanism that led to changes in the crust

• He had no evidence of continental movement

• His theory contradicted religious beliefs

Answer explanation

Wegener's idea was not accepted because he failed to provide a mechanism for how continents moved. Without a clear explanation of the forces behind continental drift, scientists were skeptical of his theory.

Tags

NGSS.HS-ESS1-5

What is the name of the single land mass that existed 300 million years ago?

• Pangaea

• Gondwana

• Laurasia

Answer explanation

The single land mass that existed 300 million years ago is called Pangaea. It was a supercontinent that eventually broke apart into the continents we know today, unlike Gondwana and Laurasia, which were separate land masses.

Tags

NGSS.MS-ESS2-3

Which process is responsible for the creation of new oceanic crust?

• Subduction

• Seafloor spreading

• Erosion

• Weathering

Answer explanation

Seafloor spreading is the process where tectonic plates move apart at mid-ocean ridges, allowing magma to rise and solidify, creating new oceanic crust. This distinguishes it from subduction, erosion, and weathering.

Tags

NGSS.MS-ESS2-2

NGSS.MS-ESS2-3

What is the main evidence for seafloor spreading?

• Fossil records

• Magnetic stripes on the ocean floor

• Earthquake patterns

• Volcanic activity

Answer explanation

The main evidence for seafloor spreading is the magnetic stripes on the ocean floor. These stripes, formed by the periodic reversal of Earth's magnetic field, show symmetrical patterns on either side of mid-ocean ridges, indicating new crust formation.

What is the theory that describes the movement of Earth's lithosphere?

• Plate tectonics

• Seafloor spreading

• Continental drift

Answer explanation

The theory of plate tectonics explains the movement of Earth's lithosphere through the interaction of tectonic plates. It encompasses concepts like seafloor spreading and continental drift, but is the overarching theory.

Tags

NGSS.MS-ESS2-3

Which scientist is credited with proposing the theory of continental drift?

• Isaac Newton

• Charles Darwin

• Alfred Wegener

Answer explanation

Alfred Wegener is credited with proposing the theory of continental drift in the early 20th century, suggesting that continents were once joined and have since drifted apart. This theory laid the groundwork for modern plate tectonics.

Tags

NGSS.HS-ESS1-5

What geological feature is commonly associated with seafloor spreading?

• Continental shelves

• Volcanic islands

• Mid-ocean ridges

• Deep-sea trenches

Answer explanation

Mid-ocean ridges are underwater mountain ranges formed by seafloor spreading, where tectonic plates move apart, allowing magma to rise and create new oceanic crust. This process is a key feature of plate tectonics.

Tags

NGSS.MS-ESS2-3

How do magnetic stripes on the ocean floor provide evidence for seafloor spreading?

• They show the age of the ocean floor

• They indicate the direction of ocean currents

• They record reversals in Earth's magnetic field

• They map the distribution of marine life

Answer explanation

Magnetic stripes on the ocean floor record reversals in Earth's magnetic field, which occur as magma solidifies at mid-ocean ridges. This pattern of stripes provides evidence for seafloor spreading, showing how new crust forms over time.

Tags

NGSS.HS-ESS1-5