| A | B |
|---|
| Geology is the study | of planet earth, including its composition and structure |
| Scientists who study earth and the processes that have | shaped earth over time are called geologists |
| uniformitarianism | is the idea that the geologic processes that operate today also operated in the past |
| ancient rocks can be understood | by observing present-day geologic processes |
| earth can be divided into three main layers, | the crust, the mantle and the core - based on the materials tha tmake up each layer |
| the rocky outer layer of Earth is the | crust |
| much of the crust is made up of | silicates, which are rocks made of compounds silicon and oxygen and often contain metals such as aluminum, iron or calcium |
| beneath the crust is the | mantle |
| the mantle is a | thick layer of hot but solid rock |
| the mantle is divided into | three layers |
| one layer of the mantle is the lithosphere, the lithosphere | is a layer of relatively cool, rigid rock that includes the uppermost part of the mantle as well as the earth's crust |
| Beneath the lithosphere (in the mantle) | is the asthenosphere |
| the asthenosphere is a layer | of softer, weaker rock that can flow slowly, the way taffy does |
| Beneath the asthensphere (in the mantle) | is the stronger lower part of the mantle called the mesosphere |
| Beneath the mantle is the | core |
| the core | is a large sphere of metal that occupies the earth's center. |
| what are the two types of forces studied by geologists | constructive forces and destructive forces |
| what are the three main layers of earth | the crust, the mantle and the core |
| a rock is a solid combination | of minerals ormineral materials |
| a mineral is a naturally ocurring, inorganic solid | with crystal structure and a characteristic chemical composition |
| minerals are | inorganic, meanting that living things did not produce them |
| describe three properties of minerals that can be used to describe them? | the properties by which minerals can be identified include their crystal structure, color, streak, luster, density, hardness, fracture and cleavage |
| crystal structure | is the way that atoms are arranged in a particular geometric shape |
| some minerals can be identified | by color |
| the color of a mineral's oowder | is know as its streak |
| the luster of a mineral | is the way in which its surface reflects light |
| the density of a mineral | depends on its chemical composition |
| hardness is the | resistance of a mineral to scratching |
| the fracture of a mineral is how | the mineral breaks |
| cleavage is a | type of fracture in which the mineral tends to split along regular, well defined planes (flat surfaces) where the bonds are weakest |
| What are the three groups into which rocks are classified? | igneous, sedimentary, and metamorphic - based on how they form |
| An igneous rock is | a rock that is formed from magma |
| magma is a mixture | of molten rock and gases, including water vapor, which forms underground |
| magma that flows out of volcanoes | is called lava |
| igneous rocks form | when molten material cools and solidifies inside Earth or at the surface |
| an igneous rock that forms underground from hardened magma is | called an intrusive rock |
| an igneous rock that forms at the earth's surface | is called an extrusive rock |
| sediment is | small, solid pieces of material that comes from rocks or living organisms |
| a sedimentary rock | is a rock that forms over time as sediment is squeezed and cemented together |
| the three main groups that geologists classify sedimentary rocks are | clastic rock, chemical rocks and organic rocks |
| sedimentary rocks that form from the | broken fragments of other rocks are called clastic rocks |
| chemical rocks form when minerals | precipitate out of a solution, like out of ocean water |
| organic rocks form when | organic marine animals die and rocks form from their shells and skeletons |
| metamorphic rock forms when | rock is transformed by heat, pressure or chemical reactions |
| most metaphoric rocks form under | high temperatures and pressures deep underground |
| metamorphic rocks with crystals arranged in parallel layers or bands are | foliated rocks |
| in the rock cycle forces within earth | and at the surface cause rocks to change form |
| the theory of plate tectonics | explains the formation and movement of Earth's plates |
| German scientist Wegener hypothesized that the continents were | once joined in a single supercontinet which then broke apart |
| the supercontinent was called | Pangaea |
| According to Wegener's hypothesis, the continents | moved slowly across Earth's surface in a process called continental drift |
| the mid-ocean ridge | is a chain of underwater mountains that extends into all of the earths oceans |
| sea-floor spreading | is the process by which new oceanic crust is created at mid-ocean ridges as older crust moves away and magma pushes upward |
| as sea-floor spreading occurs, old oceanic plates sink into the mantle in the process called | subduction |
| as a plate sinks through a subduction zone, it bends, | forming a depression in the ocean floor called a trench |
| the three types of plate boundaries are | divergent boundaries, convergent boundaries and transform boundaries |
| plates move away from each other | along a divergent boundary |
| plates come together, or collide, | at a convergent boundary |
| at a transform boundary | plates slide past each other, moving in opposite directions. |
| rock is neither created or destroyed | at a transform boundary |
| geologists found that most mountains move along | plate boundaries |
| an earthquake is a movement of Earth's lithosphere that occurs | when rocks in the lithosphere suddenly shift, releasing store energy |
| the energy relesae during an earthquake is carried | by vibrations called seismic waves |
| stress is a force that squeezes rocks | together, stretches or pulls them apart, or pushes them in different directions |
| as tectonic plates move, | they cause stree in the crust, which in turn produces faults and folds |
| a fault is a break | in the mass of rock along which movement occurs |
| a fold is a bend | in layers of rock |
| earthquakes occur because stress | forces have exceeded the strength of rock |
| the location beneath Earth's surface | where an earthquake begins is called the focus |
| P waves (primary waves) are | longitudinal waves similar to sound waves |
| S waves are | transverse waves |
| Surface waves are waves that develop | when seismic waves reach earth's surface |
| to measure earthquakes and pinpoint their epicenters, | geologists record seismic waves using seismograhs |
| a device that can detect and record | seismic waves is called a seismograph |
| the richter scale | rates earthquakes based on measurements of the times and amplitudes of seismic waves by certain seismographs |
| most earthquakes are concentrated along plate boundaries, | where many faults are found |
| a volcano is a mountain that forms | when magma reaches the surface |
| under certain conditions, small amounts of mantle rock can melt, | forming liquid magma |
| the magma rises upward through the crust | erupting at the surface as a volcano |
| before an eruption | magma often collects in a pocket called a magma chamber |
| after the magma forms in a magma chamber | it rises to the surface in a narrow, verticla channel called a pipe |
| volcanoes erupt explosively or quietly | depending on the characteristics of the magma |
| most volcanoes occur along plate boundaries or at | hot spots in the crust |
| a hot spot is a region | where hot rock extends from deep within the mantle to the surface |
| the tree major types of volcanos are | shield volcanoes, cinder cones and composite volcanoes |
| a flat volcano is called a | shield volcano |
| a small, steep-sided volcano | is called a cinder cone |
| a volcano that produces a combination | of lava and ash is called a composite volcano |
| igneous features formed by magma | include batholiths, sills, dikes and volcanic necks |
| kinetic energy | energy of motion |
| potential energy | energy that is stored as a result of position or shape |
| renewable resources | are resources that grow back after they are consumed, like trees |
| nonrenewable resources | cannot be renewed, they are gone once they are used |
| the law of conservation of energy | states energy can't be created or destroyed |
| what factors affect the strength and direction of electric fields and forces | like and opposite charges |
| how are electric charges transferred | charges can be tranferred by friction contacts and induction |
| the two types of current are | direct current and alternating current |
| a conductor is a material | through which charges can flow easily |
| an insulator is a material through which | a charge cannot flow |
| factors that affect resistance are | thickness, length and temperature |
| how does voltage produce electric current | voltage does work to increase the potential energy of electric charges |
| voltage = | current (I) x resistance (r) |
| in a series circuit | a charge has only one path through which it can flow |
| in a parallel circut | there are two or more paths through which charges can flow |
| fuses prevent | current overload in a circuit, they help maintain electrical safety |
| a circuit breaker is a switch | that opens when current in a circuit is too h igh |
| insulation protects | wires |
| grounding is the transfer | of excess energy through a conductor to earth |
| an analog signal is a smoothly | varying signal produced by continuously changing the voltage or current |
| a digital signal codes | information as a "1" or a "0" |
| what factors affect the magnetic force between two magnets | opposite, attract and like repels |
| how can you identify the north and south poles on a diagram with field lines | it is the opposite |
| what makes ferromagnetic materials magnetic | its magnetic domains |
| what factors will weaken the magnetic force of a magnet | how the domains are aligned |
| geology is a way of looking | at earth. Study of planet earth including it's composition and structure |
| what are the layers of the earth's interior | crus, mantle and the core |
| what properties are used to identify materials | luster, hardness, cleavage, color and streak |
| igneous rock | forms when molten material cools and solidifies either inside earth or at the surface |
| sedimentary rock | is a rock that forms over time as sediment is squeezed and cemented |
| metamorphic rock | has been changed by temperature, pressure or in reactions with hot water |
| explain the hypotheses of continental drift | accourding to Wegner's hypothesis, continents move slowly across earth's surface |
| describe the causes and effects of stress in Earth's crust | it can make volcanoes and earthquakes |
| the water cycle is made up of several processes including | evaporation, transpiration, consdensation, precipitation and enventual return of flowing water |
| erosion cuts canyons | through solid rock and wears away the cliffs above beaches |
| the force of gravity contributes to erosion | by mass movement when rain comes down it will help erode the land |
| when a glacier melts | it deposits its load of sediment creating a variety of landforms |
| glaciers cause many distinctive features in the landscape | includes cirques, horns, u-shapped valleys and glacial lakes |
| wind erosed the lad by | deflation and abrasion |
| features depsoited by wind | include sand dunes and loess deposits |
| geologists use radioactive | dating to determine the absolute ages of rocks |
| the time scale is based on | relative ages of rock layers and the use of radioactive dating t ofind the absolute ages of rock |
