The thinnest layer of the Earth
What is the crust
A number of rigid, but moving, pieces of Earth's surface
What is tectonic plates.
The mid-ocean ridge is an example of a ____________________ boundary and ___________________ occurs here where new ocean floor is formed.
What is divergent boundary; sea-floor spreading
Hot air or liquid is less ________________ than cool air or liquid
What is dense
The theory that all continents are fragments of Pangaea now drifting apart
What is the Continental Drift Theory
Name four of the major plates
What is any of the following North American plate, South American plate, Eurasian Plate, Indoaustralia plate, African plate, Antarctica plate, Pacific plate
States that youngest rocks of ocean floor are at divergent boundaries, moving outward
What is seafloor spreading
The rigid part of the Earth including the crust and the upper mantle (makes up the plates of the Earth)
What is the lithosphere
This is the mechanism (what causes) the plates to move
What is convection cycles in the mantle
Although the hottest layer of the Earth, this layer is solid metal
What is the inner core
The Earth's crust is thinnest under the _____________________ and thickest under the _____________________.
What is thinnest under the ocean and thickest under the continents.
The two types of convergent boundaries
What is subduction (where volcanoes often occur) and collision (where mountains are usually formed)