Tectonic Basics
What are tectonic plates?
Large pieces of Earth’s crust
About how fast do plates move each year?
A few centimeters
What does divergent mean?
It means the plates move away from each other.
Name one divergent boundary
Mid Atlantic Ridge/Iceland
Are divergent boundaries building or breaking Earth?
Building
What are tectonic forces caused by?
Heat and pressure inside the Earth
What type of currents move plates?
Convection currents
What rises into the gap at divergent boundaries?
Magma
Where is the Mid-Atlantic Ridge located?
In the Atlantic Ocean
Why are the effects of plate movement hard to notice daily?
The movement is very slow
What scientific theory explains how tectonic plates move?
Plate tectonics
Why does hot magma rise?
It is less dense than the surrounding rock, so it rises
Do divergent boundaries create or destroy crust?
They create new crust
Why does Iceland have many volcanoes?
It sits on a divergent boundary
Why might oceans become wider over time?
Becuase new ocean floor is created at divergent boundaries
What layer do plates float on?
Asthenosphere
What happens to magma after it cools?
It becomes a solid rock
What landform forms underwater at divergent boundaries?
Mid-ocean ridges
Are most divergent boundaries on land or underwater?
Underwater
Would divergent boundaries be safer or more dangerous to live near?
Generally less dangerous compared to other boundaries
Name two features created by tectonic forces
Volcanoes, earthquakes, mountains
Why does Earth’s heat cause plate movement to continue?
Because Earth's heat drives convection currents that move the plates
Why are divergent boundaries important for Earth’s surface?
They create new crust and build up Earth's surface over time
What is constantly forming at mid-ocean ridges?
New ocean floor
If plate movement stopped, what changes on Earth might stop happening?
Volcanoes, earthquakes, and new land formation