Q2- Study Guide- Earth Science

Layers of the Earth

• Crust: Outermost layer, solid and brittle
• Mantle: Middle layer, hot and semi-solid
• Outer Core: Liquid layer responsible for Earth's magnetic field
• Inner Core: Solid and extremely hot

Multiple Choice

Temperature and pressure vary in Earth’s layers. In which of the following layers of Earth are temperature and pressure the greatest?

• crust

• mantle

• outer core

• lithosphere

Earth's Magnetic Field

The Outer Core is responsible for Earth's magnetic field. It is a layer of molten iron and nickel that surrounds the solid inner core. The movement of this liquid metal creates electric currents, generating a magnetic field that protects our planet from harmful solar radiation. Without the Outer Core, Earth would be more vulnerable to space weather and cosmic rays.

Multiple Choice

Which layer of the Earth is responsible for Earth's magnetic field?

• Crust

• Mantle

• Outer Core

• Inner Core

Multiple Choice

A lava lamp contains liquid with soft wax and a light bulb at the bottom. When the lamp is on:

o The wax near the light bulb gets warmer.

o The heated wax moves towards the top.

o When the wax gets to the top, the liquid is cooler.

o The wax cools and sinks to the bottom.

How are a lava lamp and Earth alike?

• The light bulb is like the radiation of the Sun.

• The light bulb is like the gravitational pull of Earth.

• The moving wax is like the formation of mountains.

• The moving wax is like the fluid, molten areas below the crust.

Multiple Choice

The surface of the Earth is made of several tectonic plates that move at a very slow rate. What causes the plates to move?

• explosions within the Earth's mantle

• convection currents within the Earth's mantle

• contraction of the Earth's core pulling on the tectonic plates

• expansion of the Earth's core pushing on the tectonic plates

Multiple Choice

According to the Big Bang Theory, the universe is approximately 14 billion years old. It began with an explosion and an expansion of massive proportions. Which of the following statements correctly explains why the Big Bang Theory is a theory rather than a law?

• It has been conclusively proven.

• It was the first concept presented on the origin of the universe.

• It offers an explanation for many observations related to the beginning of the universe.

• It was reported in a large number of papers published by university astronomy professors.

Multiple Choice

Science needs both laws and theories to understand the whole picture of what is happening in the natural world. What is the main difference between a scientific law and a theory?

• A law is based on empirical evidence, whereas a theory is an educated guess.

• A law describes regular patterns in nature, whereas a theory explains the pattern.

• A law can be changed as new information is obtained, whereas a theory does not change.

• A law is established based on a theory, whereas a theory can be independent of prior knowledge.

Multiple Choice

Alfred Wegener proposed the theory of continental drift as a way to explain how the continents have moved on Earth’s surface over the course of geologic time. His theory states that, at one time, all of the continents were joined in one large landmass called Pangaea. Over time, the continents have moved slowly apart into the locations we are familiar with today. Which of the following describes physical evidence that would support Wegener’s theory?

• fossils of the same types of plants and animals found on different continents

• pictures of people who live on the same continent and look similar to one another

• maps from the 18th century that show the locations of continents and the oceans

• papers by fellow scientists that explain how the continents have moved apart over geologic time

Plate Tectonics

The Earth's crust is divided into plates that move due to convection currents in the mantle. There are three types of plate boundaries: convergent, divergent, and transform. Convergent boundaries result in the formation of mountains, trenches, and volcanoes. Divergent boundaries create rift valleys. Transform boundaries involve sliding of plates.

Plate Boundaries

Trivia: There are three types of plate boundaries:

• Convergent: Plates collide "CRASH"

• Divergent: Plates move apart "DIVIDE"

• Transform: Plates slide past each other "SLIDE"

Multiple Choice

What are the three types of plate boundaries?

• Convergent, divergent, and transform

• Convergent, divergent, and parallel

• Convergent, divergent, and perpendicular

• Convergent, divergent, and diagonal

Multiple Choice

How does the movement of tectonic plates create new mountains?

• When one plate gets pulled underneath another, the crust piles up underneath the top plate.

• When one plate slides past another in the opposite direction, the crust piles up.

• When continental plates crash into each other, rocks from the crust pile up.

• When the plates move apart, rocks from the crust pile up to fill in the gap.

Multiple Choice

If the locations of earthquakes over the past 10 years were plotted on a world map, which of the following would be observed?

• Earthquakes do not seem to occur in any consistent pattern.

• Earthquakes generally occur along the edges of tectonic plates.

• Earthquakes most frequently occur near the middle of continents.

• Earthquakes occur with the same frequency everywhere on Earth.

Multiple Choice

The shown diagram is of a mid-ocean ridge where sea floor spreading occurs. Using data from satellites, scientists estimate that the Atlantic Ocean is expanding in width by about two centimeters each year. Which of these statements best describes the cause of this sea floor spreading?

• Evaporation of heat from the mantle cools it to form new sea floor.

• Conduction of heat from the mantle expands the crustal plates at mid-ocean ridges.

• Convection of heat within the mantle results in less dense magma rising at mid-ocean ridges, building new sea floor.

• Radiation of heat from the mantle causes plates to collide, resulting in mountain formation and earthquakes at mid-ocean ridges.

The Rock Cycle

• Igneous Rocks: Formed through the melting and cooling of rocks.
• Sedimentary Rocks: Formed through weathering & erosion, breakdown of rocks into sediments, compaction & cementation.
• Metamorphic Rocks: Formed through heat & pressure.
• Law of Superposition: Rocks stack in layers, with the oldest at the bottom and the youngest at the top.

Multiple Choice

Which type of rock is formed through weathering & erosion, breakdown of rocks into sediments, compaction & cementation?

• Igneous Rocks

• Sedimentary Rocks

• Metamorphic Rocks

• Law of Superposition

Multiple Choice

The sand found along the Gulf of Mexico coast of Florida originated in granite formed from slowly cooling magma in the Appalachian Mountains. When this sand is buried and compacted, it will become sandstone. The sandstone may be moved deeper underground where it will be subjected to heat and pressure to become quartzite. What is the rock cycle for this sequence of transformations?

• igneous rock → metamorphic rock → sedimentary rock

• metamorphic rock → igneous rock → sedimentary rock

• igneous rock → sedimentary rock → metamorphic rock

• metamorphic rock → sedimentary rock → igneous rock

Multiple Choice

A geologist studies the side of a mountain with many layers of Earth exposed. The geologist wants to know more about when a particular layer of sandstone formed. Which observation would best help determine the age of the sandstone layer?

• the width of the layer of sediment

• the type of fossils in the sediment

• the amount of moisture in the sediment

• the color of the minerals in the sediment

Multiple Choice

Limestone forms as ocean water evaporates and leaves calcium carbonate behind, which is then deposited on the ocean floor. What type of rock can be formed in this way?

• igneous

• magma

• metamorphic

• sedimentary

Determining Fossil Age

To determine the age of fossils, examine the surrounding rocks and fossils using the Law of Superposition and the Fossil Record. This provides a relative age estimate. For absolute age, use radioactive dating to measure carbon decay over time. Radioactive dating is the most reliable method. Folding in rocks can be identified by the wave-like patterns caused by intense heat and pressure. Human activities such as erosion, pollution, and habitat destruction can have a significant impact on the Earth's surface and lead to extinction of organisms.

Multiple Choice

Use the Law of Superposition to analyze this diagram that shows rock layers near the surface of the Earth. Which rock formation listed below is the oldest?

• A

• B

• C

• D

Radioactive Dating

Trivia: Radioactive dating is the most reliable method to determine the absolute age of fossils. It measures carbon decay over time. This method helps scientists estimate the age of fossils and rocks, providing valuable insights into Earth's history. Law of Superposition and examination of surrounding rocks and fossils are also important in determining relative age.

Multiple Choice

A scientist finds a fossil in a rock that does not match the general pattern of the other fossils found in the area. The scientist wants to know if this fossil is older than the other fossils. Which process will best help the scientist determine the general age of the fossil?

• Observe the types of minerals present in the fossil.

• Determine the amount of erosion evident on the rock.

• Test the amount of radioactive elements found in the rock.

• Measure the amount of rock attached to the fossilized bone.

Multiple Choice

What is the most reliable method to determine the absolute age of fossils?

• Examine surrounding rocks and fossils

• Use the Law of Superposition

• Measure carbon decay over time using radioactive dating

• Identify folding in rocks by wave-like patterns

Multiple Choice

What method would a geologist use to determine the approximate age of a rock found in a newly discovered formation?

• Test the rock with radioactive dating.

• Charge the rock with electricity to see if it is magnetic.

• Smash the rock with a hammer to see how it crumbles.

• Compare the appearance of the rock with similar samples from other formations.

Multiple Choice

A geologist studies a layered rock to determine its age. Bacteria fossils from the Precambrian Age are found in the rock's upper layers, but no fossils are found in the rock's bottom layers. Which of these conclusions about the rock is best supported by the evidence?

• The age of the entire rock is equal to the age of the fossils.

• The rock formed quickly through a series of rapid changes.

• The top layers of the rock are much older than its bottom layers.

• The bottom layers of the rock could have formed before life occurred

Multiple Choice

As more people have crowded into coastal areas, shoreline erosion has become a more high-profile problem. Scientists fear that shoreline erosion may be accelerating due to changes in climate and human activity. Which of these elements is least likely to increase the rate of erosion along the Florida coast?

• rising sea levels

• more sand dunes

• destruction of mangrove swamps

• increased frequency of hurricanes