Seafloor Spreading Part 1 The Creation of New

Seafloor Spreading Part 1: The Creation of New Oceanic Crust http: //earthref. org/SCC Scripps Classroom Connection

“Continental Drift” Evidence http: //earthref. org/SCC Scripps Classroom Connection

Seafloor Ages & Magnetic Anomalies Age http: //earthref. org/SCC Magnetics Scripps Classroom Connection

Seafloor Spreading http: //earthref. org/SCC Scripps Classroom Connection

Age and Magnetic Field recorded in the seafloor and spread to each side of the ridge Each side of the ridge is the same!! http: //earthref. org/SCC Scripps Classroom Connection

Creation of Magnetic Stripes on the Seafloor http: //earthref. org/SCC Scripps Classroom Connection

How Fast is the Seafloor Spreading? Slow: 10 -50 km/Myr Intermediate: 50 -90 Km/Myr Fast: 90+ km/Myr Full Spreading Rate (km/Myr) http: //earthref. org/SCC Scripps Classroom Connection

Ridge Segment http: //earthref. org/SCC Scripps Classroom Connection

Conclusions Part 1 ● There is lots of evidence pointing to seafloor spreading! ● New seafloor forms at seafloor spreading centers. ● Seafloor forms about as fast as your nails grow! ● Seafloor spreading does not happen in a straight line.

Seafloor Spreading Part 2: The Life Cycle of the Seafloor http: //earthref. org/SCC Scripps Classroom Connection

Is the Earth Expanding? http: //earthref. org/SCC Scripps Classroom Connection

“Pacific Ring of Fire” http: //earthref. org/SCC Scripps Classroom Connection

Seafloor Destruction: “Subduction Zones” Earthquakes http: //earthref. org/SCC Scripps Classroom Connection

Seafloor Destruction: “Subduction” http: //earthref. org/SCC Scripps Classroom Connection

http: //earthref. org/SCC Scripps Classroom Connection

Conclusions Part 2 ● The Ring of Fire is defined by earthquakes and volcanoes. ● The Ring of Fire is caused by subduction. ● Seafloor is destroyed by subduction. ● Deep trenches happen at subduction zones. ● The Pacific ocean is shrinking; the Atlantic ocean is growing.