CHAPTER 5: Earth dynamics

Lesson 2: landforms at plate boundaries

?? Essential Questions What features form where two plates converge? What features form where two plates diverge? What features form where two plates slide past each other?

Vocabulary Ocean trench Volcanic arc Transform fault Fault zone

Landforms Created by Plate Motion Tectonic plates move slowly, only 1-9 cm per year Compression, tension, and shear stresses are at work at plate boundaries San Andreas Fault is the result of shear stresses where plates move past each other Ural Mountains are created by compression stresses where plates collide

Landforms Created by Compression Mountain Ranges Ocean Trenches Are deep, underwater troughs created by one plate subducting under another plate at a convergent plate Volcanic Arcs A curved line of volcanoes that forms parallel to a plate boundary

Landforms Created by Tension Mid-Ocean Ridges They form under water at divergent boundaries as oceanic plates move away from each other Continental Rifts They can form enormous splits in Earth’s crust Large blocks of crust move downwards, creating valleys between two ridges

Landforms Created by Shear Stresses Transform Faults Where tectonic plates slide horizontally past each other Fault Zones An area of many fractured pieces of crust along a large fault

Homework Textbook: Page 162 #1, 2, 3, 5, 6 & 9 Write down question and answer Workbook: Page 162 - 163