Plate Boundries

Question 1

What processes occur at plate boundaries that impact earthquake magnitude?

Answer 1

The processes occurring at plate boundaries affect the magnitude of earthquakes.

These processes include the movement of tectonic plates, which can lead to stress accumulation and release.

Question 2

How do the properties of magma influence volcanic eruptions?

Answer 2

The properties of the magma play a crucial role in determining the magnitude and frequency of eruptions.

Factors such as gas content, viscosity, and temperature are significant.

Question 3

What characterizes earthquakes at divergent boundaries?

Answer 3

Earthquakes tend to be small and short at divergent boundaries.

These earthquakes typically have low magnitude.

Question 4

What is the nature of volcanic eruptions at divergent boundaries?

Answer 4

Eruptions at divergent boundaries tend to be small and effusive.

Effusive eruptions involve the flow of lava rather than explosive activity.

Question 5

What type of lava is usually involved in eruptions at divergent boundaries?

Answer 5

The eruptions are usually of basaltic lava.

Basaltic lava is characterized by low gas content, low viscosity, and higher temperature.

Question 6

Define effusive eruptions.

Answer 6

Eruptions involving the flow of lava rather than explosive activity.

This type of eruption is common at divergent boundaries.

Question 7

What are the characteristics of basaltic lava?

Answer 7

• Low gas content
• Low viscosity
• Higher temperature

These properties contribute to the nature of eruptions at divergent boundaries.

Question 8

What are convergent boundaries?

Answer 8

Boundaries where tectonic plates move toward each other, often resulting in subduction and the formation of mountains.

Question 9

What is the primary geological activity associated with subduction zones?

Answer 9

Earthquakes and volcanic eruptions.

Question 10

What type of eruptions are commonly associated with subduction zones?

Answer 10

Violent eruptions.

Question 11

What type of lava is often produced during violent eruptions?

Answer 11

Rhyolite lava.

Question 12

Fill in the blank: The zone where most friction and pressure build up occurs in subduction zones is called the _______.

Answer 12

[Benioff zone]

Question 13

What is the relationship between gas content and the type of eruptions?

Answer 13

High gas content tends to lead to more explosive eruptions.

Question 14

What is the rock type typically associated with high viscosity lava?

Answer 14

Rhyolite.

Question 15

What characteristics describe basalt lava?

Answer 15

• Low viscosity
• Black to dark brown in color.

Question 16

True or False: All volcanic eruptions in subduction zones are non-violent.

Answer 16

False.

Question 17

What is seafloor spreading?

Answer 17

The process by which new oceanic crust is formed at mid-ocean ridges and gradually moves away from the ridge.

Question 18

What does palaeomagnetism study?

Answer 18

The study of the magnetic properties of rocks to understand historical changes in Earth’s magnetic field.

Question 19

What are the two periods of magnetism identified in seafloor spreading?

Answer 19

A. Period of normal magnetism
B. Period of reverse magnetism

Question 20

What is ridge push?

Answer 20

A tectonic process that develops due to the elevation of mid-ocean ridges, causing tectonic plates to move away from the ridge.

Question 21

What is slab pull?

Answer 21

The force exerted by the weight of a sinking tectonic plate at a subduction zone.

Question 22

Fill in the blank: The lithosphere is composed of the _______ and the uppermost part of the mantle.

Answer 22

[crust]

Question 23

What is the asthenosphere?

Answer 23

A semi-fluid layer of the upper mantle that allows for the movement of tectonic plates.

Question 24

True or False: Gravity is a main driving force in plate tectonics.

Answer 24

True

Question 25

What role does friction play at subduction zones?

Answer 25

Friction resists the movement of tectonic plates as one plate sinks beneath another.

Question 26

What is the depth of the outer core?

Answer 26

Between the mantle and the inner core, approximately 2,900 km deep.

Question 27

What is the significance of slab pull in plate tectonics?

Answer 27

Slab pull is significant as it helps to explain the movement of tectonic plates at subduction zones.

Question 28

List the layers of the Earth from the surface to the center.

Answer 28

• Crust
• Lithosphere
• Asthenosphere
• Mantle
• Outer core
• Inner core

Question 29

Fill in the blank: The process of _______ is necessary for slab pull to occur.

Answer 29

[subduction]