| A | B |
|---|
| geologists | scientists who study the earth and its composition |
| uniformitarianism | the idea that the earth goes through the same geological changes now as in the past |
| three layers of the earth | crust mantle and core |
| lithosphere | layer of the mantle with cool,rigid rock |
| asthenosphere | second layer of the mantle with soft flowing "taffy" rock |
| mesosphere | lowest level of mantle with stiff rock to the core |
| outer core | large sphere in earth's center -liquid constantly moving causing magnetic field |
| inner core | solid center of the earth under great pressure |
| properties of metals | crystal,luster,streal,color,density |
| plate tectonics | theory that earth's lithoshere moves slowly on top of mantle |
| Wegner's hypothesis | theory that continents were one |
| Pangaea | ancient supercontinent |
| Wegner's challenge | problem with explaining how continents plow through ocean floor |
| mid-ocean range | area in ocean where rocks are the youngest |
| subduction | plates that SINK into the crust |
| trench | depression in the ocean floor |
| sea floor spreading | creates new ocean crust at the mid ocean ridges |
| divergent boundaries | plates that MOVE AWAY from each other |
| convergent boundaries | plates that come together or collide |
| transform boundaries | plates that SLIDE past each other |
| stress | force that pushes together and pulls apart plates |
| fault | a break in a mass of rocks |
| fold | a bend in a layer of rocks |
| epicenter | location on earth's surface that is the center of an earthquake |
| P waves | seismic waves similar to sound waves (longitudinal) that travel through solid and liquids |
| S waves | seismic waves cannot pass through liquids travel at right angles |
| seismograph | a device to detect earthquake |
| MMS (moment magnitude scale) | scale to measure intensity of earthquakes |
| magma | amount of mantle rock that melts andis less dense than rock; rises to the surface |
| pipe | narrow vertical chamber where magma collects |
| crater | bowl shaped pit on the top of a volcano |
| quiet eruption | volcano magma that is very hot low silica- low viscosity |
| explosive eruption | high silica magma that clogs volcano pipes cause this |
| shield volcano | type of volcano low flat low viscosity |
| composite volcano | type of volcano that forms from explosive ash and lava |
| cinder volcano | volcano formed from ash and cinders in an explosive |
| batholith | largest type of intrusive igneous rock |
| igneous rock | type of rock formed from molten material that cools on the earth's surface is extrusive |
| sedimentary rock | rocks that form from minerals or weathering or living organism shells |
| metamorphic rock | rocks formed by heat and pressure deep underground |
