Earth's Layers & Surface Events
What are the four main layers of the Earth in order from the surface to the center?
Crust, mantle, outer core, inner core.
What are the three main types of rocks in the rock cycle?
Igneous, sedimentary, and metamorphic.
What are the large pieces of Earth’s crust that move slowly over the mantle called?
Tectonic plates.
What is one kind of evidence that shows Earth has changed over millions of years?
Fossils or rock layers showing past life and environments.
In science, what does the word theory actually mean?
A well-supported explanation based on evidence, not just an opinion or guess.
What is one example of how humans have changed Earth’s surface?
Deforestation, urbanization, or building roads changes land surfaces.
What layer of Earth do we live on, and what is it made of?
The crust, made of solid rock and tectonic plates that float on the mantle.
Which layer of the Earth is made of slow-moving, flowing rock that causes convection currents?
The mantle.
How is igneous rock formed?
From cooled magma or lava.
What two types of changes can plate movement cause on Earth’s surface?
Slow changes like mountain building, and rapid changes like earthquakes and volcanic eruptions.
What do fossils of marine animals found on mountain tops tell scientists?
Those rocks were once underwater, showing Earth’s surface has moved or uplifted over time.
Why do scientists sometimes revise or update scientific theories?
Because new evidence or technology can lead to new interpretations that improve our understanding.
How can pollution affect the air and water on Earth?
It can harm living things, make water unsafe to drink, and damage ecosystems.
How does heat inside Earth affect the planet’s surface?
It causes convection currents in the mantle, which move tectonic plates and form volcanoes, mountains, and earthquakes.
What process causes magma to cool and harden into igneous rock?
Crystallization or solidification of molten material.
What two processes are needed to form sedimentary rock?
Compaction and cementation of sediments.
What causes the movement of Earth’s tectonic plates?
Convection currents in the mantle driven by heat from Earth’s core.
How do scientists in different fields (like geology and biology) work together to explain Earth’s history?
They combine different types of evidence—like rock layers (geology) and fossils (biology)—to build a more complete scientific explanation.
According to the Law of Superposition, which rock layer is the oldest—top or bottom?
The bottom layer is the oldest because new layers form on top of older ones.
What happens when humans change the flow of water, like by building dams or canals?
It can cause flooding, drought, or erosion in new areas and disrupt natural habitats.
How do weathering, erosion, and deposition work together to shape Earth’s surface?
Weathering breaks down rock,
Erosion moves the particles, and
Deposition drops them in a new place to form new landforms.
Name two ways Earth’s surface can be built up and two ways it can be worn down.
Built up: deposition, volcanic activity, mountain building
Worn down: weathering, erosion
How do plate tectonics help form mountains?
When plates collide or push together, the land is forced upward, forming mountains.
What’s the difference between a scientific theory and a scientific law?
A theory explains why something happens (e.g., plate tectonics).
A law describes what happens (e.g., law of gravity).
Give one example of how scientific knowledge has changed because of new evidence.
The theory of plate tectonics replaced the older idea of continental drift when seafloor spreading evidence was discovered.
What is radioactive dating, and what does it help scientists determine?
It measures how much radioactive material remains in a rock or fossil to find its absolute age in years.
How do scientists study and monitor the effects of human impact on Earth?
They use satellites, climate models, and data from fields like biology, geology, and meteorology to analyze changes over time.
How can scientists use fossils and rock layers to learn about Earth’s past?
They use the Law of Superposition and fossil evidence to determine relative age and how environments or species have changed over time.
How do Florida’s landforms—like beaches, dunes, and deltas—show the effects of weathering, erosion, and deposition?
They’re constantly shaped and reshaped by wind and water movement; sand and sediments are carried away (erosion) and dropped elsewhere (deposition).
Explain how weathering, erosion, and plate movement all connect in the rock cycle.
Weathering and erosion break down rocks into sediments.
Sediments form new rocks through compaction.
Plate movement pushes rocks deep into Earth, where heat and pressure form metamorphic or melt into magma.
How does gravity relate to plate tectonics and Earth’s structure?
Gravity pulls denser materials toward Earth’s center, helping drive subduction and keeping Earth’s layers organized by density.
How do rock layers and the Law of Superposition help scientists understand Earth’s geologic history?
Older rock layers are found below younger ones, helping scientists determine the relative age of fossils and events.
How do rock layers and fossil records together show that Earth has changed over time?
Fossils and rock layers provide physical evidence that life and environments on Earth have evolved gradually through natural processes.
How does climate differ from weather, and why does this matter when studying human impact?
Weather is short-term (daily conditions).
Climate is long-term patterns in an area.
Studying climate trends helps scientists track how human activities change Earth’s systems.
What are two major ways humans can cause or speed up changes to Earth’s surface?
Deforestation, construction, and mining increase erosion,
Pollution and greenhouse gases alter air, water, and climate systems.