Plate Tectonics 7th Grade Science

Lesson 1 Earthquake- vibrations in the earth caused by sudden release of energy, as a result of the movement of rocks along a fault Seismologist- scientist who studies earthquakes

Lesson 2 Earthquake Waves P-Wave: primary wave, first and compressional (back and forth) S-Wave: secondary, second and moves at right angles, much rougher Surface Waves: Elliptical and back and forth on surface of earth, most destructive

Lesson 3 Seismogram- paper that records earthquake Seismograph- device that measures an earthquake’s intensity Epicenter – imaginary point on earth that sits on top of the focus Focus – where the earthquake begins inside the earth

Earthquake Diagram

Lesson 4 Plate Boundary-pieces of broken lithosphere meet, 3 types Convergent (collide), Divergent (divide) and transform (slide) Ring of Fire-encircles the Pacific Ocean, an area of volcanic and earthquake activity Magnitude- measure of total amount of energy released in an earthquake, each interval 32 times more energy is released, Richter scale measures Intensity- measure of damage done during an earthquake, Mercalli scale measures

Lessons 1-4 Challenge Words Liquefaction: strength and stiffness of soil is reduced by earthquake shaking, occurs in saturated soils and allows soil particles to move (think of liquid vs. solid) Lithosphere: crust and uppermost mantle, where earthquakes occur Subduction Zone: 2 lithospheric plates come together

Lesson 5 – Use your apple diagram for the parts of the earth Parts of the Earth (inside to outside)-think of an apple Inner Core/like the seeds of an apple Outer Core/pocket that holds the seeds Mantle/meaty part of the apple-what you eat Asthenosphere/in upp. Mantle, layer that allows the lithosphere or our plates to move Lithosphere/bite out of the apple-upp.mantle/crust or a plate Crust/skin of the apple

Lesson 6 Lithosphere: Cool, solid outer shell of earth which is made of Crust and Upper Mantle and makes up our plates Asthenosphere: layer of mantle directly below the lithosphere and allows the lithosphere to move. Mid-Ocean Ridge: A mountainlike landform that develops when plates separate and new ocean lithosphere forms, Divergent Boundary Subduction: The movement of a tectonic plate beneath another plate Ex. Oceanic lithosphere is more dense and subducts beneath the Continental lithosphere, Convergent Boundary

Lesson 7 Friction – surface resistance between two objects, ex. Plates rubbing against one another, the greater the friction, the greater the force or resulting earthquake. Plate Tectonics: Theory that lithosphere is broken into segments/plates that float on the asthenosphere and is associated with earthquakes, and volcanic activity.

Lesson 8 Convection in the Mantle: the heat from our core travels to the Mantle and rises since it is less dense than the cooler material at the top of the mantle. The cooler material is more dense so it sinks. This cycle repeats itself and is known as a convection current. (Think about our Convection experiment with the bottle and candle. ) This process drives our plate movement.

Plate Boundaries, Pangaea, and the Pacific Ring of Fire Plate Boundaries Map – shows us the separation between plates and where earthquakes and volcanic activity might occur Divergent – divide or pull apart, ex. Mid Atlantic Ridge Convergent – collide and form mountains, ex. Himalayas Transform– slide next to one another, ex. San Andreas fault Pangaea – when all the continents were connected over 250 million years ago, evidence rock, fossil and climate clues Pacific Ring of Fire – area that encircles the Pacific Ocean and is home to most earthquake and volcanic activity

Lessons 9 – 12 (Our destructive and constructive Volcanoes) Volcano – a mountain with a crater or vent in which molten material, gas, and ash can escape Types of: Shield: has gently sloping sides and gentler eruptions ex. Mt. Kilauea, Hawaii Cinder-cone: Steep mountain with large cone like crater at the time, can have great eruptions ex. Paricutin in Mexico Composite or Stratovolcano: Made of alternating layers of lava or ash, can have major eruptions, Ex. Mt. Pinatubo in the Philippines

Volcano types Shield Volcano Cinder-cone Composite or Stratovolcano

More Vocabulary Volcanic Ash/tephra: Trapped gases from a volcano emit these tiny fragments of volcanic remains/glass into the atmosphere Magma: Molten material beneath the earth’s surface Lava: Molten material on the earth’s surface Hot Ash Cloud: the pressure released during a volcanic eruption can produce these clouds due to density differences between ash and air and convection

Instruments used to study Volcanoes Seismograph Gas Sensors Tiltmeter