8th grade Ch 9 Sec 1/2

A ___ is a sensitive device used to detect magnetic fields on the seafloor.

Parallel ridges that form where blocks of crust move up or down along faults

Plates collide together at ___ plate boundaries.

The crust and upper mantle make up the ____

State in which magnetized objects would reverse direction and orient themselves to point south

The theory of ___ explains how new crust is created at mid ocean ridges

The presence of the same ___ on several continents supports the hypothesis of continental drift

The ___ beneath the continents and the seafloor is made of molten rock

New oceanic crust forms along a mid-ocean ridge and older oceanic crust moves from the ridge

This theory states that Earth's surface is divided into rigid plates that move 

A fossil plant that helps support the theory of continental drift is 

Some early mapmakers thought the coast of ____ matched the coastline of Africa.

What new technology was used to map the seafloor beginning in the 40s and 50s?

Wegener believed the continents assembled about ____ years ago.

While studying the ocean floor, scientists found ___ bands of magnetism.

A(n) ___ is an underwater mountain chain.

The main points of evidence for continental drift are ___

Where tectonic plates slide horizontally past each other

Bands of rock on the seafloor indicate that Earth's magnetic field has

Plates slide past each other at ____ plate boundaries.

Underwater troughs created by 1 plate subducting under a plate at a convergent plate boundary

A single supercontinent believed to have once existed called ___

A change in Earth's magnetic field is called a(n) ___

The youngest rocks on the ocean floor are located ___

One plate is forced under another in a(n) ____

An area of many fractured pieces of crust along a large fault

The magnetic pattern of ocean-floor rocks on one side of an ocean ridge is ___

Earth's plastic like layer is called the