Seafloor Age and Magnetic Stripe Evidence

Seismic Waves Reveal Earth's Interior is a good opening, and Classify Boundaries From Plate Motion Arrows gives students the vocabulary for the mountain sheets. The earthquake hazard sheet uses a fictional region, so it works on its own.

Fill in seafloor ages on both sides of a ridge, graph them and find the spreading rate. The directions on the page read: Read the text and study the diagram. Use the numbers on the diagram to fill in the table for both sides of the ridge. An answer key is included.

Yes, both. We made it for 7th grade Earth science, and it works the same at home or at school. At home, a student can work through it alone and then go over it with you, which shows quickly what is solid and what needs another look. In class it works as independent practice, homework or a warm-up, and you can print one copy or a full set.

P waves travel through solids and liquids, but S waves travel only through solids. Where waves arrive or stop tells scientists which layers are solid or liquid. Seismic Waves Reveal Earth's Interior also gives depth and density for each layer.

New ocean floor forms at a mid-ocean ridge, and rock farther from the ridge is older. Magnetic minerals in cooling lava lock in Earth's magnetic field, leaving stripes of normal and reversed polarity. Seafloor Age and Magnetic Stripe Evidence has students graph age against distance.

India moved north and collided with Asia about 50 million years ago. Continental crust is thick and light, so neither plate sank far into the mantle. Continental Collision and the Himalayas uses three cross sections.

A forecast gives the probability of an event over a period of time. A prediction names the time and often the place and size of a coming event. Earthquake Hazard Maps and Probability explains why scientists can forecast earthquakes but not predict them.