Drift Happens!
What is Pangea?
Pangea was a supercontinent that existed about 300–200 million years ago, when all the Earth’s landmasses were joined together as one giant continent before drifting apart into the continents we have today.
Why do you think the ocean floor has ridges and valleys instead of being flat?
The ocean floor has ridges and valleys instead of being flat mainly because of the movement of Tectonic Plates.
What is the formula for density?
Mass/Volume = Density
What type/s of plate boundaries cause Earthquakes?
Transform and convergent boundaries mainly cause earthquakes.
What are plate boundaries?
Plate boundaries are the edges where two tectonic plates meet.
Who proposed the Continental Drift Theory (Pangea)?
Alfred Wegener
How do fossils support the theory of plate tectonics?
The same fossils are found on continents now far apart, showing they were once connected (Pangea).
What is Topography?
Topography is the shape and features of the land, like mountains, valleys, hills, and plains.
What type/s of plate boundaries cause Volcanoes?
Convergent boundaries – where plates collide, one plate can sink (subduct) and melt, creating magma that rises to form volcanoes.
Divergent boundaries – where plates pull apart, magma rises to fill the gap and form new crust
Hot spots – not a boundary, but volcanoes can also form in the middle of a plate.
What are the THREE types of plate boundaries? (MUST name all 3!)
Convergent Plate Boundary
Divergent Plate Boundary
Transform Plate Boundary
How do plates move on Earth’s surface?
Tectonic plates move on Earth’s surface because the hot, soft layer of the mantle below them flows slowly, carrying the plates along like rafts on a moving liquid.
Why do scientists create models to study tectonic plates and the Earth’s interior?
Because the processes happen slowly and deep underground, models help visualize and understand plate movement and Earth's layers.
What is the Ring of Fire?
A path around the Pacific Ocean where many volcanoes and Earthquakes happen because tectonic plates are moving.
What type of plate boundary forms mountain ranges?
Mountain ranges are primarily formed at convergent plate boundaries, where two tectonic plates move toward each other.
What is Seismic Activity?
Seismic activity refers to the shaking or vibrations of the Earth’s crust, usually caused by the sudden movement of rocks along faults. These vibrations are what we feel as earthquakes.
In short: Seismic activity = Earth’s crust moving and shaking.
Where does seafloor spreading happen?
It happens at places called mid-ocean ridges, where magma from inside the Earth comes up, cools, and forms new rock. As new rock forms, it pushes the old rock away, making the ocean bigger.
What is the difference between an oceanic trench and a mid-ocean ridge?
A trench is a deep valley where plates are colliding and one sinks; a ridge is a mountain range where plates pull apart and magma rises.
What is Bathymetry?
Bathymetry is the study and measurement of the depth and shape of underwater land, like oceans, seas, and lake floors.
Is it possible for an earthquake to occur away from a plate boundary?
Yes, old faults or cracks in the crust, or stress from distant plate movements, can cause earthquakes away from plate boundaries.
How does temperature affect the density of a substance?
When the temperature of a substance increases, its particles move faster and spread apart, so its density decreases.
Why is rock near ridges younger?
Rock near mid-ocean ridges is younger because new crust is constantly being formed there. Magma rises from the mantle, cools, and becomes new rock, pushing older rock farther away from the ridge.
How does ancient glacial evidence show continents were once connected?
Ancient glaciers left scratches and rocks on land that is now too warm.
These scratches match on different continents, showing the land was once joined together.
What is a hot spot?
A hot spot is a place where magma from deep inside the Earth rises to make volcanoes, usually not at a plate boundary.
What is a Mid-Ocean Ridge?
A mid-ocean ridge is an underwater mountain range where tectonic plates are moving apart (divergent boundary) and new ocean crust is formed by rising magma.
What type of boundary is the San Andreas Fault?
A transform boundary, two tectonic plates slide past each other horizontally, which causes earthquakes. The San Andreas Fault is where the Pacific Plate and North American Plate slide past one another in California.