Question 1

As new seafloor rocks are formed, they record the direction of Earth's changing magnetic field.

Accepted Answer

This is the process of magnetic striping, where the iron-rich minerals in the newly-formed seafloor rocks align with Earth's magnetic field at the time of their formation, creating a record of the direction and polarity of the field.

Question 2

Synclines usually form ridges and anticlines usually form valleys.

Accepted Answer

The statement is actually the opposite of reality. Synclines usually form valleys and anticlines usually form ridges.

Question 3

The oldest portions of continental crust are called shields.

Accepted Answer

This is true. Shields are the oldest and most stable portions of continental crust, composed of igneous and metamorphic rocks that are over 2 billion years old.

Question 4

Pangaea was a single large landmass.

Accepted Answer

Pangaea was a single large landmass that existed over 200 million years ago before it began to break apart and form the continents as we know them today.

Question 5

Plate movement is caused exclusively by friction from the mantle as it moves against the lithosphere.

Accepted Answer

While friction between the mantle and lithosphere does play a role, plate movement is primarily caused by convection currents within the mantle. These currents are driven by heat from the Earth's core, and they drag the plates along with them as they flow.

Question 6

The uplift and building of mountains is called orogenesis.

Accepted Answer

This statement is true. Orogenesis refers to the process of mountain building and uplift.

Question 7

Mid-ocean ridges and rift valleys form at divergent plate boundaries.

Accepted Answer

Mid-ocean ridges and rift valleys form when two tectonic plates move apart from each other at a divergent plate boundary. This allows magma from the mantle to rise up and create new crust, which builds up over time to form underwater mountain ranges with deep valleys between them.

Question 8

Relative plate velocity is the rate of plate movement relative to the movement of an adjoining plate.

Accepted Answer

Relative plate velocity is indeed the rate of plate movement relative to the movement of an adjoining plate.

Question 9

Subduction zone volcanoes make up the Ring of Fire.

Accepted Answer

The Ring of Fire is a region around the edges of the Pacific Ocean where many active subduction zone volcanoes are located.

Question 10

Plate movement can create volcanic eruptions.

Accepted Answer

When tectonic plates move, they can create friction and pressure that can trigger volcanic eruptions. This is because the movement can lead to the release of magma and gases from beneath the Earth's surface.

Question 11

Hawai'i's newest forming island is occurring on the far northwestern end of the island chain.

Accepted Answer

Hawai'i's newest forming island, Lo'ihi, is actually developing off the southeastern coast of the Big Island, not the northwestern end of the island chain.

Question 12

Earth's magnetic field reverses on average about every 2 million years.

Accepted Answer

Earth's magnetic field reverses at irregular intervals, averaging about every 200,000 to 300,000 years, not every 2 million years.

Question 13

The most geographically extensive mountain ranges on Earth are the mid-ocean ridges.

Accepted Answer

The mid-ocean ridges are a continuous underwater mountain range that spans across the Earth's oceanic basins, making it the most extensive mountain range on Earth.

Question 14

At hot spots, as the mantle flows upward it melts into magma because it encounters less pressure near the base of the lithosphere.

Accepted Answer

This statement is true. At hot spots, the mantle rises due to heat and pressure and encounters less pressure near the base of the lithosphere, leading to melting and the formation of magma.

Question 15

The youngest seafloor is always along mid-ocean ridges.

Accepted Answer

Mid-ocean ridges are where new oceanic crust is formed through volcanic activity, so the seafloor along these ridges is indeed the youngest.

Question 16

Plate tectonics is called a unifying theory because it explains many different and seemingly unrelated physical phenomena.

Accepted Answer

This statement is true. Plate tectonics helps to explain various geologic phenomena such as earthquakes, volcanoes, mountain building, ocean basins and continental drift, which were previously thought to be unrelated.

Question 17

The plates of the lithosphere are floating on molten rock.

Accepted Answer

The answer of The plates of the lithosphere are floating...

Question 18

Mid-ocean ridges are usually volcanically active.

Accepted Answer

Mid-ocean ridges are divergent boundaries where new oceanic crust is formed through volcanic activity. Therefore, they are usually volcanically active.

Question 19

The Tibetan Plateau and the mountains surrounding it contain the largest volume of ice outside of the polar regions.

Accepted Answer

The Tibetan Plateau and the mountains surrounding it are often referred to as the "Third Pole" and contain the largest volume of ice outside of the polar regions, with over 46,000 glaciers covering a total area of 100,000 square kilometers.

Question 20

A tsunami is a large ocean wave generated by earthquakes.

Accepted Answer

A tsunami is a series of ocean waves with very long wavelengths (typically several hundred kilometers) caused by large-scale disturbances of the ocean, such as earthquakes, volcanic eruptions, landslides, and meteorite impacts.

Quiz 13: Drifting Continents: Plate Tectonics