| A | B |
|---|
| atmosphere | outermost, gaseous layer, composed mainly of nitrogen and oxygen |
| hydrosphere | layer of water, covers 70% of surface |
| crust | rocy outer layer of earth |
| mantle | dense shell found between the crust and the outer core |
| lithosphere | the crust and the uppermost portion of the mantle |
| asthenosphere | paritally melter layer of the mantle that lies between the lithosphere |
| outer core | made of liquid iron and nickel |
| inner core | solid ball of iron and nickel |
| how old is the earth | 4.6 billion yrs old |
| shape of earth | bulges at equatoe flattened at poles |
| 2 theories of continent formation | pangea, great lava flows |
| 4 types of boundaries | diverging, sliding, colliding, subduction |
| diverging | <- -> mid ocean ridges- mid-atlantic ridge |
| sliding | <=>(one goes up over another)-faults- san anderas fault |
| colliding | -><- mountains- himalyas, appalachian, ural mtns |
| subduction | ->v one goes down- trenches and volcanoes- mariana trenchm, peru and chile trench |
| craton | oldest part of a continent |
| 3 sources that add to continental growth | deep sea sediments, volcanic rock, sediments |
| thin-skinned thrusting | the pushing of thin, horizontal sheets of rock from continental margins over great distances along nearly level fault surfaces. |
| terrane | a large block of lithospheric plate that has been moved, often a distance thousands of km, and attatched to the edge of a continent |
| theory of plate tectonics- who made it | wegener |
| theory of plate tectonics suggested... | the continents are not fixed, but drift about the surface of the earth |
| the big continent was called | pangea |
| 5 types of evidence for continental drift | geographcal, geological, climatic, paleomagnetism, and biological |
| geographical | some continents' coasts would almost interlock if rearranged like pieces of a puzzle |
| geological | old mtn zones of matching ages appear as belts crossing southern continents if these are joined together in a certain way |
| climatic | glacia deposits and rocks scratched by stones in moving ice show that ice covered huge tracts of southern continents 300 million years ago |
| paleomagnetism | alignments of magnetized particles in old rocks show that southern continents all lay near the south pole about 300 mil yrs ago |
| biological | identical fossil land plants and land animals are found in southern continents now widely separated by sea. |
| how many major plates on earth | 12 |
| paleomagnetism means | ancient records of magnetism |
| normal polarity | pointing north |
| reversed polarity | pointing south |
| how many periods of reversed and normal polarity over the past 4 mil years | 4 |
| earthquake | a sudden shaking of the ground where stress-deformed rocks broke along a fault and now snap back into shape but in a new position |
| where do earthquakes occur | sliding boundaries |
| a break or crack in the earths crust along which movement occurs is called a | fault |
| elastic-rebound theory | stresses along fault lines as plates collide. |
| focus | location of the earthquake within the earth |
| epicenter | the point of the surface directly abouve the focud |
| p waves | can travel through any material |
| s waves | can only travel through solids |
| l waves | only waves that travel along the surface |
| p waves travel____ as fast as s waves | twice |
| seismograph | detects and records earthquake waves |
| how can u tell how far away an earthquake was? | difference in time between p and s waves |
| what can a single seismograph station determine | the distance from the epicenter |
| richter scale | determines the strength or magnitude of an earthquake by measuring the amount of energy released |
| normal fault | stretching beraks rocks along a steep fault plane, and one block drops or rises against the other |
| reverse fault | compression forces one block up and over another |
| strike slip fault | horizontal shearing along a vertical fault plane |
| rock cycle | the set of processes that creat and destroy the crust of the earth |
| 3 basic formsd of rocks | igneous, sedimentary, and metamorphic |
| characteristics of igneous rock | once molted, interlocking crystal patterns |
| how is igneous rock formed | starts as magma, cools when reaches the surface |
| erosion | the moving of products of weathering from one location to another |
| glacier | a moving mass of ice on land. formed by the recrystallization of snow, which moves uner its own weight |
| valley glacier | found in valleys, long, slow moving, wedge-shaped stream of ice |
| continental glacier | larger than a valley glacier. moves outward from center towards sea coasts. very thick |
| nunataks | tallest peaks that stick out of the ice |
| firn | freashly fallen snow that is compressed and recrystallized into a rough granular ice material |
| calving | the process when if a glacier reaches the sea/ocean, pieces of it break off to form ice bergs |
| striations | parallel scratches formed when glaciers debris is dragged over bedrock |
| crique | semicircular basins in mountain areas where snow may pile up to eventually form a glacier |
| arete | a sharp, knife edged ridge formed between two parallel mountain glaciers |
| horn | a sharp, pyramid-shaped pek carved by 3 or more glaciers flowing from the same peak |
| u shaped valleys | glaciers widen, deeped, and starighten v- shaped cross sections and basically carve and form troughs or...... |
| till | deposits made by the ice itself, as undorted masses of stones and rocks |
| outwash | deposits made by the meltwater streams that come from a glacier, which produce layered sediments |
| moraine | an accumulation of glacial till |
| ground moraine | material left underneath the glacier |
| lateral moraine | material piled to the sides of the glacier |
| medial moraine | if 2 glaciers move sidce by side,their inside lateral moraines join |
| terminal moraine | the material left where the glacier stops advancing |
| erratic | large boulders that have been picked up and dropped off by glaciers |
| drumlins | long upside down canoe-shaped hills |
| outwash plains | flattened area in front of terminal moraine where glacial meltwater deposited sediment and flattened it out |
| esker | long, winding ridges formed from sediments trapped in tunnels under the glacier |
| kame | small, cone shaped piles of debris formed when streams flowing on top of the glaciers deposit the debris at the edge of the glacier |
| kettle | a circular hollow left in an outwash plane when a buried ice block melts |
| crique lake | a crique now filled with water |
| kettle lake | small lakes formed when a block of ice gets wedged into the ground , leaving a hole, the melts and fills the hole with water |
| moraine-dammed lake | long narrow lake carved out by glaciers then surrounded by glacier's moraines |
