Q&A Hero

Q: As a stream flows downslope, if discharge doubles but the cross-sectional area of the channel stays the same, what happens to the average stream speed? A) Average stream speed stays the same. B) Average stream speed decreases. C) Average stream speed increases. D) Stream flow stops.

Q: As streams move downslope, channel dimension generally A) decreases with decreased discharge. B) increases with decreased discharge. C) narrows. D) widens.

Q: Within a stream channel, the speed of stream flow is greatest A) at the bottom of the stream bed. B) in the middle of the channel at the water's surface. C) at the channel sides. D) mid-channel between the stream bed and the water's surface.

Q: The cross-sectional area and shape of a stream is called A) hydraulic gradient. B) discharge. C) channel dimension. D) channel geometry.

Q: The volume of water that flows past a given point in a channel during a specified time is called A) load. B) gradient. C) discharge. D) runoff.

Q: The speed of water in a stream is affected by A) hydraulic gradient, recharge, and channel geometry. B) gradient, discharge, and channel geometry. C) high gradient, laminar flow, and erosion. D) gradient, turbulence, and friction.

Q: In general, a stream with a high discharge tends to have A) increased laminar flow. B) increased turbulent flow. C) a high velocity. D) a narrow stream channel.

Q: The discharge of a stream is directly related to the A) volume of water flowing past a given point in a channel in a given amount of time. B) cross-sectional area of a channel and the average stream velocity. C) average stream speed and frictional contact. D) channel geometry and frictional contact.

Q: Seismic waves are classified as body waves and surface waves. An example of a body wave is a A) Primary wave (P-wave). B) Love wave. C) Rayleigh wave. D) Tertiary wave (T-wave).

Q: The speed of a seismic wave depends on A) the type of material it travels through. B) how far it has to travel. C) its amplitude. D) its frequency.

Q: Tectonic interaction between plate boundaries does not explain A) magma production and the variety of igneous rocks. B) mountain building. C) polar wandering. D) global distribution of earthquakes and volcanoes.

Q: Water causes partial melting of the mantle at which type of plate boundary? A) convergent boundaries B) divergent boundaries C) transform-fault boundaries

Q: Earthquake activity is associated with A) divergent, convergent, and transform plate boundaries. B) convergent and transform plate boundaries. C) divergent and convergent boundaries. D) transform plate boundaries.

Q: Volcanic activity is associated with A) divergent, convergent, and transform boundaries. B) convergent and transform boundaries. C) divergent and convergent boundaries. D) divergent, convergent, and plate tectonic boundaries.

Q: At divergent boundaries the dominant rock type is A) basalt. B) granite. C) andesite. D) basalt, granite, and andesite.

Q: Granite does not readily form near oceanic-oceanic convergent boundaries because A) granite forms from granitic magma and most oceanic material is basaltic in origin. B) the magma formed at this type of boundary is not conducive to producing granitic type rocks. C) oceanic-oceanic convergence often results in the eruption of andesitic lavas. D) all of the above

Q: What geologic features are explained by plate tectonics?

Q: How does movement in a normal fault differ from that in a reverse fault?

Q: Distinguish between anticlines and synclines.

Q: How are tensional and compressional forces related to faulting and folding?

Q: Where does a tsunami usually occur? A) transformfault boundary B) underwater reverse fault C) divergent boundary D) continentalcontinental convergent boundary

Q: Volcanoes do not form at which type of convergent plate boundary? A) oceanicoceanic boundaries B) oceanicconvergent boundaries C) continentalcontinental convergent boundaries

Q: The Himalayan Mountains formed at which type of plate boundary? A) transformfault boundary B) Oceaniccontinental convergent boundary C) divergent boundary D) continentalcontinental convergent boundary

Q: Transform-fault boundaries usually form A) between two segments of a mid-ocean ridge. B) between two other transform-fault boundaries. C) between a mid-ocean ridge and a subduction zone. D) in the rift of a mid-ocean ridge.

Q: Earthquakes are caused by the A) friction between diverging plates. B) sudden release of energy that is stored elastically in deforming rocks. C) expansion of Earth's crust. D) combined motion of tectonic plates.

Q: A tsunami is unlike most other water waves mainly because it A) is stronger. B) has a very long wavelength. C) moves very fast. D) is energetic.

Q: Damage from an earthquake is most severe when the A) epicenter is close to the surface. B) surface material is composed of unconsolidated sediments. C) buildings and structures are poorly constructed. D) all of the above

Q: Compressive stress causes rocks to buckle and fold. In a syncline fold, the rocks at the fold axis (the core) are A) younger than those away from the axis. B) older than those away from the axis. C) more deformed than those away from the core. D) less deformed than those away from the core.

Q: Rocks begin to deform when they are stressed. Near Earth's surface, when stress is severe, the rock A) behaves plasticallyit folds and flows. B) Is brittleit breaks producing faults and fractures. C) has brittle deformationit folds and flows. D) has plastic deformationit faults and fractures.

Q: The majority of earthquakes occur where A) lithospheric plates meet. B) the asthenosphere touches the lithosphere. C) the land surface is made of unconsolidated sediments. D) narrow zones of land touch.

Q: Tsunami are correctly referred to as A) seismic sea waves. B) tidal waves. C) energy waves. D) mega waves.

Q: The energy in an earthquake is released A) all at once. B) before the quake, after the quake, and during the quake. C) as an epicenter focus. D) in unconsolidated rock.

Q: When stress exceeds a rock's elastic limit, the rock A) permanently loses its original form. B) can either break or flow. C) becomes plastic. D) can lose its original form and either break or flow.

Q: Reverse faults are the result of A) tension. B) compression. C) divergence. D) heat.

Q: Rocks in the core of an anticline are ________ than rocks away from the core. A) higher B) lower C) older D) younger

Q: Tensional forces cause the crust to A) buckle and fold, thereby shortening the crustal surface. B) buckle and fold, thereby lengthening the crustal surface. C) stretch and pull, thereby shortening the crustal surface. D) break and fracture, thereby lengthening the crustal surface.

Q: Compressive forces cause the crust to A) buckle and fold, thereby shortening the crustal surface. B) buckle and fold, thereby lengthening the crustal surface. C) stretch and pull, thereby shortening the crustal surface. D) break and fracture, thereby lengthening the crustal surface.

Q: A fault in which the footwall has moved down relative to the hanging wall is called a A) normal fault. B) reverse fault. C) transform fault. D) horizontal fault.

Q: The moment magnitude scale measures the energy released by an earthquake. For each increase in magnitude, the energy released increases A) ten-fold. B) logarithmically. C) by 10. D) 30 times.

Q: The Mercalli scale measures an earthquake's A) effects. B) damage. C) intensity. D) intensity, damage, and overall effect.

Q: The Richter magnitude scale measures an earthquake's A) frequency. B) energy in terms of ground shaking. C) damage. D) all of the above

Q: The San Andreas fault in California is a A) thrust fault. B) strike slip fault. C) normal fault. D) reverse fault.

Q: Most of the state of Nevada is in the Basin and Range Province. The predominant active fault for this region is A) thrust faulting. B) reverse faulting. C) normal faulting. D) none of the above

Q: When rock is subjected to compressive force, it may fault. If rocks in the hanging wall are pushed up over rocks in the footwall, it is called a A) reverse fault. B) strike slip fault. C) normal fault. D) none of the above

Q: Compression cannot produce A) anticlines. B) synclines. C) normal faults. D) reverse faults.

Q: The stress that occurs when material is pulled apart is called A) compressional stress. B) tensional stress. C) shear stress. D) simple stress.

Q: When you stretch a rubber band, you are applying A) compressional stress. B) tensional stress. C) shear stress. D) simple stress.

Q: An anticline is a fold in which the limbs bend A) downward. B) upward.

Q: The Richter magnitude scale is logarithmic, each 1-point increase on the scale corresponds to a A) 100-fold increase in the amplitude of ground shaking. B) 30-fold increase in the amplitude of ground shaking. C) 10-fold increase in the amplitude of ground shaking. D) an increase of 30 times the energy for each magnitude.

Q: In an undeformed sequence of rocks, the youngest rocks are found A) at the bottom of the rock sequence. B) as an eroded bed. C) at the top of the rock sequence. D) in the core of an anticline.

Q: In a folded sequence of rocks we find older rocks at the axis of the fold and younger rocks away from the fold axis. The fold is A) called a syncline. B) called an anticline. C) plunging. D) tilted.

Q: In a folded sequence of rocks we find younger rocks at the axis of the fold and older rocks away from the fold axis. The fold is A) called a syncline. B) called an anticline. C) plunging. D) tilted.

Q: Why are older rocks more likely to be found on the continents than on the ocean floor?

Q: How old is the Atlantic Ocean? For how many years has magma been extruding in the mid-Atlantic?

Q: What is the major source of energy responsible for earthquakes in southern California?

Q: Subduction is the process of one lithospheric plate descending beneath another. Why does the oceanic portion of the lithosphere undergo subduction while the continental portion does not?

Q: What kind of plate boundary separates the South American Plate from the African Plate?

Q: Why are most earthquakes generated near plate boundaries?

Q: Why is it that the most ancient rocks are found on the continents, and not on the ocean floor?

Q: Describe the plate tectonic theory.

Q: Briefly describe the different types of plate boundaries.

Q: According to plate tectonic theory, the San Andreas fault is a A) convergence zone. B) divergence zone. C) subduction zone. D) transform fault.

Q: The San Andreas fault A) stretches from the Gulf of California to Cape Mendocino, California, and separates the Pacific Plate from the North American Plate. B) accommodates all the motion between the Pacific Plate and the North American Plate. C) is presently inactive. D) all of the above

Q: The occurrence of earthquakes in the absence of seafloor spreading, oceanic trenches, or volcanic activity is a characteristic feature of A) convergent boundaries between plates. B) divergent boundaries between plates. C) subduction zones. D) transform fault boundaries between plates.

Q: Convection in the mantle is caused primarily by A) heat moving from the crust to the core. B) conduction. C) gravity and temperature differences. D) friction of overlying lithosphere.

Q: Magma is generated at all of these plate boundaries except A) divergent boundaries. B) oceanic-oceanic convergent boundaries. C) oceanic-continental convergent boundaries. D) continental-continental convergent boundaries.

Q: The dominant force at convergent boundaries is A) compression. B) tension. C) shearing. D) similar to that in normal faulting.

Q: The dominant force at divergent boundaries is A) compression. B) tension. C) shearing. D) similar to that in reverse faulting.

Q: Subduction occurs as a result of A) slab pullgravity pulls older and denser lithosphere downward. B) horizontal plate accommodation. C) upwelling of hot mantle material along the trench. D) lubrication from the generation of andesitic magma.

Q: The process in which one plate bends and descends beneath another plate is called A) subduction. B) seduction. C) segregation. D) sinking.

Q: Transform faults are areas of crustal A) formation. B) destruction. C) subduction. D) accommodation and plate movement.

Q: Another term for a spreading center is A) convergent boundary. B) divergent boundary. C) transform fault boundary. D) none of the above.

Q: Convergent boundaries are regions of A) great mountain building. B) plate subduction. C) plate collision. D) plate collision, subduction, and mountain building.

Q: Convergent boundaries are areas of A) compressional forces that crunch the crust and generate a spreading center. B) tensional forces that stretch the crust and generate a spreading center. C) crustal formation. D) plate collision.

Q: Which one of the following is not a type of plate collision? A) continental divergence B) oceanic-continental C) continental-continental D) oceanic-oceanic

Q: Spreading centers occur along A) trenches. B) transform faults. C) mid-ocean ridges. D) the northern and western margins of the Juan de Fuca Plate.

Q: Divergent boundaries are areas of A) crustal formation. B) crustal destruction. C) continuous, high magnitude earthquakes. D) intense compressional forces.

Q: Divergent boundaries are areas of A) tensional forces that stretch the crust and generate a spreading center. B) compressional forces that crunch the crust and generate a spreading center. C) compressional forces that crunch and shorten the crust by folding and faulting. D) plate collision.

Q: The longest mountain chain in the world is the A) mid-ocean ridge. B) Himalayas. C) Appalachians. D) Sierra Nevada.

Q: The oldest rocks are found A) at convergent boundaries. B) at divergent boundaries. C) in the ocean basins. D) on continental land.