Plates & Boundaries
This is the specific type of boundary where an oceanic plate descends beneath a continental plate and is "recycled."
What is a Subduction Zone?
These bulbous rock structures are formed by the rapid surface cooling of magma in cold ocean water at mid-ocean ridges.
What is pillow lava?
This is the scientific study of earthquakes and the passage of seismic waves through the Earth.
What is Seismology?
This process bends and twists rock due to compression and is usually found where plates come together.
What is Folding?
This is the specific "power source" that drives seafloor spreading by moving hot material within the Earth's aesthenosphere.
What is nuclear fission? (or: What are Convection Currents?)
This plastic-like layer, which is 10% molten, allows tectonic plates to move because of convection currents.
What is the Asthenosphere?
This specific gas, emitted during eruptions, can cause "volcanic winters" by reflecting sunlight away from the Earth.
What is Sulphur Dioxide?
This layer of the Earth is solid specifically because of the "immense pressure" it is under.
Where is the Inner Core?
In a fault system, this is the name for a massive block of crust that has been pushed upward between two faults.
What is a Horst (or Block Mountain)?
These volcanic features, like Hawaii, are created by a crack in the lithosphere where basaltic magma builds up over time.
What are Hot Spots?
These are the giant "rigid slabs" of solid rock that move independently on the Earth's surface.
What are Tectonic Plates?
Often described as "rivers of wet concrete," these mudflows are historically the most deadly of all volcanic hazards.
What are Lahars?
These are the fastest seismic waves, capable of passing through both solids and liquids.
What are P-waves (Primary waves)?
This is the name for an "up-fold" in the rock layers.
What is an Anticline?
This type of scale is used for volcanic explosivity because it can represent a much larger range of numbers than a linear scale.
What is a logarithmic scale?
While oceanic plates are recycled, continental plates do not sink because they possess this physical property compared to both oceanic plates and the asthenosphere.
What is lighter OR less dense?
Even when not erupting, volcanoes release gases through these small surface openings.
What are fumaroles?
Because elements differentiated by weight when the Earth was molten, these "lighter elements" rose to form the crust and mantle.
What are Silicates? (or silica-rich rocks)
This type of fault is specifically associated with two sections of the earth’s crust moving almost horizontally past each other.
What is a Strike-slip Fault?
This is the characteristic shape of a volcano created by fluid, low-viscosity basaltic lava.
What is a Shield Volcano?
This term refers to the "gradual increase in size" of the Earth during its development due to the addition of materials from space.
What is Accretion?
This type of lava, common in subduction zones, is high in silica, thick, sticky, and slow-moving.
What is Andesite (or Rhyolite)?
The Earth’s magnetic field is believed to be generated by the movement of molten iron and nickel in this specific layer.
What is the Outer Core?
This famous California landmark is a prime example of a Transform Fault boundary.
What is the San Andreas Fault?
Every 500,000 years, the Earth's magnetic pole does this, which is recorded in solidifying basaltic magma.
What is reverse (or a Magnetic Reversal)?