Sea Floor Spreading Reading

This is a 50 000 mile chain of volcanic mountains in the middle of the ocean.

Sea floor spreading reading.

Layers of the earth pdf or google doc guided reading. This lesson is the first day of a two day lesson involving the process of sea floor spreading. Seafloor spreading occurs along mid ocean ridges large mountain ranges rising from the ocean floor. This idea played a pivotal role in the development of the theory of plate tectonics which revolutionized geologic thought during the last quarter of the 20th century.

Once the basalt cools completely into solid rock the. Seafloor spreading theory that oceanic crust forms along submarine mountain zones and spreads out laterally away from them. The mid atlantic ridge for instance separates the north american plate from the eurasian plate and the south american plate from the african plate the east pacific rise is a mid ocean ridge that runs through the eastern pacific ocean and separates the pacific plate from the north american. Seafloor spreading is a process that occurs at mid ocean ridges where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge.

Sea floor spreading the longest chain of mountains in the world is the system of mid ocean ridges. Earlier theories by alfred wegener and alexander du toit of continental drift postulated that. Sonar is a device that bounces sound waves off underwater objects and then records the echoes of these sound waves. Plate boundaries pdf or google doc convection currents worksheet pdf or google doc sea floor spreading worksheet pdf or google doc coloring plates activity.

Since the lesson itself is pretty ambitious in terms of what students are tasked to do it necessitates at least two periods i have around 60 minutes period of task time in order for students to complete everything. Most basalt magmas contain abundant molten iron. 3 the mid ocean ridge is found throughout the oceans of the earth. Continental drift sea floor spreading pdf or google doc pg.

As magma starts to harden into rock iron rich minerals solidify first. Their crystals are pulled into alignment by the earth s magnetic field just like a compass needle is pulled towards magnetic north. Once students learn about the mid ocean ridge drifting continents and how the earth moves from the reading they can put their knowledge to the test with a works. Hess believed that sea floor spreading is the answer to the mystery of continental drift.

In the mid 1900s scientists mapped the mid ocean ridges using sonar.