Practice Set 4.3 - Earth's Features

 Geologists have been studying a site to learn more about the fossils there. Study the image that the geologist made. Which of the following claims can be supported by the evidence from the image?

• The site has always been a forest environment.

• The site was a forest before it was an ocean environment.

• The site was an ocean environment before it was a forest.

• The site has always been an ocean environment.

Answer explanation

The most recent fossils will be closer to the top of this outcrop. These fossils (layers 4 and 5) are from land plants and animals. The fossils get older as you move down the outcrop. These fossils (layers 1 and 2) are from marine organisms. 

A team of scientists has come across some interesting rock patterns in the earth at one specific location. What might explain the formation of these rock layers?

• An earthquake may have caused the ground to shift.

• A volcano added layers of lava causing the ground to move.

• Human activities like building roads and houses caused the ground to move.

• Wind caused weathering and erosion over time, shifting the ground.

Answer explanation

There is a pattern of layers and the pattern is offset, which indicates that an earthquake shifted the layers. 

Study the diagram of the fossils shown. Assume there have been no changes to Earth's layers in this location. Which statement most accurately describes the age of the fossils?

• The oldest fossils are found in Layer 3.

• The youngest fossils are found in Layer 1.

• The fossils in Layers 2 and 3 are the same age.

• The relative ages of the fossils cannot be compared from this picture.

Answer explanation

There is a natural order involved in dating fossils, and the youngest fossils are the ones found in the topmost layer of Earth. 

The students in a science class must find a way to demonstrate how rainfall helps shape the land. Which of the following investigations would best represent these ideas?

• Place an ice cube on a baking sheet, and set it in the sun until it melts.

• Pour water on top of a pile of sand, and watch as it moves the sand around.

• Place a fan in front of a pile of sand, turn it on, and watch the sand blow away.

• Set a large rock in a tray of water, and watch as the rock weathers by the next day.

Answer explanation

The water represents rainfall, and the sand represents the land and how it can be changed by the water. 

Scientists study and track the locations of active volcanoes and earthquakes on maps to look for patterns. Which statement best describes the data and patterns you see in the map?

• There are equal numbers of volcanoes and earthquakes.

• Anywhere there is an earthquake, a volcano will always be in that same location too.

• Most of the volcanoes on Earth are located in the center of the oceans.

• Volcanoes that occur on continents most often occur along the coasts.

Answer explanation

Volcanoes that occur on continents most often occur along the coasts. 

Which is an example of a living organism that causes the earth to be reshaped?

• a snake slithering through the grass

• a bird building a nest in a tree branch

• a prairie dog burrowing into the ground

• a bear scratching its back against a rock

Answer explanation

A prairie dog burrows into the ground, which means it moves dirt, small rocks, and sand out of its way as it makes a hole. This is an example of a living thing reshaping Earth’s structures. 

Jamila wants to travel somewhere where she has the best chance of seeing a volcano, but from a safe distance. She doesn’t like to go on boats, so she wants to make sure it is on land. Use the map below to explain which location would be the best place to do this.

• Australia; there are several volcanoes just off the coast.

• Africa; there are several volcanoes inland.

• Russia; there are several earthquakes, so there has to be several volcanoes here, too.

• South America; there are several volcanoes inland.

Jeremiah lives in a house that is very close to a flowing river. He notices that his town is getting a lot more rain this year than normal. The water in the river is moving much faster than normal and is higher up on the sides of the river. What actions could Jeremiah take to make sure this river water does not end up in his house?

• He could consider ideas to slow down the erosion from the increase in rainfall.

• He could consider ideas to increase the erosion from the increase in rainfall.

• He could consider ideas to maintain the erosion at the same levels.

• There is no way to reduce the risk of erosion from the potential flooding.

Answer explanation

Since the fast moving river with more water causes more erosion, and is likely to cause flooding, Jeremiah needs to consider ideas to slow down the erosion. 

Engineers are designing a sea wall to protect a seaside town. The purpose of the sea wall is to prevent the ocean from causing erosion. The wall will be built into the ground and will stand up out of the sand. The design must first go through a series of tests to make sure it will work. What is the best way for the design to be tested to show what needs to be improved?

• Build a small model of the sea wall. Submerge the model into fresh water, and see how long the water takes to erode the wall.

• Build a small model of the sea wall and the coast that it protects. Use a spray bottle or hose, and pour water directly over the model to see how well it stands up in a storm.

• Build a small model of the sea wall and the coast that it protects. Place the model into an earthquake simulation machine, and see at which strength the sea wall begins to crack.

• Build a small model of the sea wall and the coast that it protects. Place the model into a pool. Make waves to test at which height the sea wall no longer protects the coast from the waves.

Answer explanation

Knowing the height at which the sea wall becomes ineffective can help engineers improve the design by making the sea wall taller, if they need to. 

Technology can be improved over time to meet the needs of society. Which is an example of an improvement that can cause people to be better protected from natural hazards?

• stream gauges that provide data on possible flooding

• alarms that go off when fires in fireplaces become too hot

• a machine that can identify the types of rocks at a location

• weather vanes that tell which direction the wind is coming from

Answer explanation

Floods are natural hazards; knowing the height of a stream could gauge the possibility for flooding in an area.