| A | B |
|---|
| Fault | A break in Earth's crust where rocks have slipped past each other |
| Granite | Continental crust mainly consist of granite |
| Alfred Wegner | First propose the theory of continental drift |
| Wegner's theory was rejected because | it couldn't explain what force pushes or pulls continents |
| Subduction | The process by which oceanic crust sinks beneath trenches |
| Plates | Section of Earth's lithosphere is broken into separate pieces that slowly moves over the asthenosphere |
| Geologists | scientists who study the forces that make and shape planet Earth |
| Radiation | Transfer of energy through space |
| Conduction | Transfer of heat within a material or between materials that are touching |
| Convection | Transfer of heat by movement of a fluid |
| Convection | Cooler, denser fluids sink to the bottom |
| Mid-ocean ridge | Undersea mountain chain where new floor is produced |
| What erupts from a mid-ocean ridge | molten material comes up |
| Asthenosphere | soft layer of mantel that the lithosphere floats on, can bend like plastic |
| Lithosphere | Rigid layer made up of the uppermost part of the mantle and crust |
| Sea-flooring spreading | process that continually adds new material to the ocean floor |
| Continental drift | Hypothesis that continents slowly moved across Earth's surface |
| Transform plate/boundary | Two plates slip or slide past one anothe |
| Convergent plate/boundary | Two plates come together, collide-one goes on top of the other |
| Divergent plate/boundary | To plates divide, move apart from one another |
| Stress | Force that acts on rock to change its shape or volume *tension |
| P waves | Seismic waves that arrive first, primary waves, compress and expand the ground like an accordian |
| Anticlines | Fold in rock that bends upward to form an inch |
| Synclines | Fold in rock that bends downward to form a valley |
| Focus | Point beneath Earth's surface where the crust breaks and triggers an earthquake |
| Tension | Type of stress that pulls on the crust and stretches rock |
| Seismograph | An instrument used to measure and record ground movements during an earthquake |
| Liquefaction | Process that occurs when an earthquake's shaking turns loose soil into mud |
| Normal Fault | Fault is at an angle - the hanging wall slips downward |
| Strike-slip fault | rocks slip past each other side-ways with little up or down motion |
| Reverse fault | Same structure as a normal fault, but hanging wall moves upward past the footwall |
| Shearing | Stress that pushes rock in two opposite directions, causes strike-slip faults |
| Compression | Stress force that squeezes rock until it folds/breaks |
| Plateau | Large flat area of land that is elevated high above sea level |
| Moment magnitude scale | rating system that estimates the total energy released by an earthquake |
| Epicenter | Point on Earth's surface directly above an earthquake's focus |
| Tsunamis | Water displaced by an undersea earthquake |
| Hot spot | Area where magma melts through the crust in the middle of a plate |
| Magma chamber | magma collects in a pocket inside a volcano |
| Physical properties of magma from explosive eruptions | thick, sticky, high viscosity, high in silica |
| Volcanic soils contain | potassium and phosphorus |
| Lava plateau | Layers of thin, runny lava that flows over a wide area before they cool and harden |
| Stages of volcano activity | Dormant - sleeping Extinct - dead, unlikely to erupt again Active - one that is erupting or showing signs it will erupt again |
| Magma | Molten mixture of rock - forming substances, gases and water deep in Earth's mantle |
| Ring of fire | Belt of volcanoes around the rim of the Pacific Ocean |
| Silica | Compound that is made up of the particles oxygen and silicon, is one of the most abundant materials in Earth's crust, more silica = thicker magma |
| Volcanic neck | Forms when magma harden in a volcano's pipe and is later exposed |
