Seafloor Spreading
What scientist proposed the theory of seafloor spreading?
Who is Harry Hess?
What theory explains how Earth’s plates move and interact?
What is plate tectonics?
How do scientists divide the Geologic Time Scale?
By major changes in life forms and Earth’s history.
The Law of Superposition states that the oldest rocks are found where?
What is at the bottom?
What is the fourth planet from the Sun?
What forms at a mid-ocean ridge?
What is new oceanic crust?
What causes tectonic plates to move?
What are convection currents in the mantle?
What evidence did Alfred Wegener use to support continental drift?
Fossils, rock layers, and climate clues found on different continents.
Which type of rock most often contains fossils?
What is sedimentary rock?
What is a Waxing Gibbous?
What is the phase of the moon that occurs after the first quarter?
What tool did scientists use to map the ocean floor and discover mid-ocean ridges?
Sonar
What forms when two continental plates collide?
What are mountain ranges?
How do seafloor spreading and subduction work together?
They recycle Earth’s crust — new crust forms at ridges and old crust is destroyed at trenches.
What do scientists use index fossils to determine?
What is the relative age of rock layers?
What is the agency that demoted?
What is the IAU?
What process pulls old oceanic crust back into the mantle?
What is subduction?
What type of boundary causes earthquakes like the San Andreas Fault?
What is a transform boundary?
What is the area called where most earthquakes and volcanoes occur around the Pacific Ocean?
What is the Ring of Fire?
Which layer of Earth is broken into plates?
What is the lithosphere?
The spinning movement of the earth on it's axis is called a
What is a Rotation?
Why is the youngest rock found near mid-ocean ridges instead of trenches?
Because new crust forms at ridges and moves outward over time.
What is the name of the supercontinent that existed 200 million years ago?
What is Pangaea?
What is a trench and how is it formed?
What is a deep valley formed when one plate subducts beneath another.
Why do plates float on the mantle instead of sinking into it?
Because the plates are less dense than the underlying mantle.
How many days are in a year?
What is 365.25 days?