Plates in Motion
Who first discovered plate tectonics
Alfred Wegener
What is mitigation?
Actions that reduce damage but do not stop natural hazards
What is molten rock called below Earth’s surface?
Magma
What force pulls rock and soil downhill in a landslide?
Gravity
What is the thinnest and least dense layer of Earth?
What is the crust?
In which atmospheric layer does weather occur?
Troposphere
What layer of Earth do the tectonic plates make up?
Lithosphere
What mitigation strategy helps people leave dangerous areas safely?
Evacuation plans
Which type of magma is thick and sticky and causes bigger explosions?
High-silica magma
Name one factor that increases landslide risk.
Steep slopes, heavy rainfall, earthquakes, or loss of vegetation
Which Earth layer is made of silicate rock and flows slowly?
The mantle
Which layer contains the ozone layer?
Stratosphere
What is the theory of plate tectonics?
The Earth's outer crust is divided into several plates that glide over the plastic-like and less rigid upper mantle.
Why are building codes considered mitigation?
They reduce damage and injuries during disasters
Which volcano is wide with gentle slopes and quiet eruptions?
Shield volcano
Why does heavy rainfall increase landslide risk?
It adds weight to soil and reduces friction
Which layer is liquid iron and nickel?
The outer core
In which layer do meteors burn up?
Mesosphere
What is the ring of fire?
A long chain of volcanoes that surround the pacific ocean.
Why is mitigation important even though disasters still occur?
It saves lives and protects property
Why does high-silica magma cause explosive eruptions?
It traps gases because it is thick
Why does deforestation increase landslide risk?
Tree roots that hold soil in place are removed
What important feature of Earth is created by the outer core?
Earth’s magnetic field
Name two ways the atmosphere protects Earth.
Burns up meteors and absorbs harmful radiation
What causes Plate tectonics to move?
Convection
How do Earth’s systems interact during natural hazards, and name one mitigation strategy that reduces risk.
Earth’s interior causes hazards that interact with the atmosphere and surface, and mitigation such as evacuation plans or building codes reduces damage.
Which volcano is small and made of ash and rock fragments?
Cinder cone volcano
Why do earthquakes and volcanoes occur at plate boundaries?
Plate movement releases stored energy
How do temperature and density change as you move deeper into Earth?
They increase
Why is the atmosphere necessary for liquid water to exist on Earth?
it traps heat and maintains pressure