3. Plate tectonics operating over geologic time has changed the patterns of

land, sea, and mountains on Earth’s surface. As the basis for

understanding this concept:

a. Students know features of the ocean floor (magnetic patterns, age, and seafloor

topography) provide evidence of plate tectonics.

b. Students know the principal structures that form at the three different kinds

of plate boundaries.

c. Students know how to explain the properties of rocks based on the physical

and chemical conditions in which they formed, including plate tectonic

processes.

d. Students know why and how earthquakes occur and the scales used to

measure their intensity and magnitude.

e. Students know there are two kinds of volcanoes: one kind with violent

eruptions producing steep slopes and the other kind with voluminous lava

flows producing gentle slopes.