Vocabulary
The sinking movement of ocean floor back into the mantle
subduction
German meteorologist ______________ further developed the hypothesis that all of the continents had once been fused together, and that over time they had drifted apart.
Alfred Wegener
The Earth’s crust and upper mantle also known as the ___________ are broken into sections called plates
Lithosphere
An ____________ is the shaking and trembling that results from the sudden movement of part of the Earth’s crust.
earthquake
What are the three types of boundaries?
Divergent Boundaries, Convergent Boundaries, and Transform Boundaries
undersea valleys that are the deepest parts of the ocean
ocean trenches
Wegener’s continental drift hypothesis stated that the continents had once been joined to form a single _____________.
Supercontinent.
The theory that pieces of Earth’s lithosphere are in constant motion, driven by _________________ in the mantle.
convection currents
Directly above the focus, on the Earth’s surface is the _____________.
epicenter
What are the three main types of seismic waves?
Primary, Secondary, and Surface waves
Plates come together or converge
convergent boundary
Most scientists rejected Wegener’s ground breaking hypothesis because __________________________.
he could not provide an explanation of how the plates moved
Breaks in Earth’s crust where rocks have slipped past each other.
faults
Invented in 1893 by John Milne, a seismograph detects and measures ________________.
seismic waves
What are the three different types of volcanoes?
Cinder cones, Shield volcanoes, and Composite volcanoes
the force that acts on a rock to change its shape or volume.
stress
Continents actually move with lithospheric plates that are pushed by ________________.
Mid-Ocean ridges
Convection Currents in the mantle move the plates as the core heats the slowly-flowing _____________.
asthenosphere
The seismograph record of waves is called a
seismogram
_____________ study earthquakes. They can determine the strength of an earthquake by the height of the wavy line recorded on the paper.
Seismologists
Walls of rock grind past each other in opposite directions
strike-slip fault
It is believed that convection currents cause movement in the ___________ where heat rises from interior.
asthenosphere
A famous fault at a Transform Boundary is the __________________________.
San Andrea's Fault in California
There is often a funnel-shaped pit or depression at the top of a volcanic cone. This pit is called a _______.
crater
What are four types of lava?
Dark-colored lava, Light-colored lava, combination lava, and gaseous lava.