geology exam # 3 chapters 9-13

16. To survive an avalanche you generally have to be rescued within __________ minutes.

15

15. Major earthquakes are often followed by somewhat smaller events known as ________.

Aftershocks

35. Highly impermeable layers such as compacted clay or shale are known as ________.

Aquitards

4. Large circular downwarped structures are called ________.

Basins

At low temperatures (i.e. shallow crustal depths), rocks tend to behave in a ______________ manner and fracture.

Brittle

28. ________ describes the total sediment load transported by a stream

Capacity

19. Which area of the US is most prone to landslides (mass wasting)?

Cascade Mountains, Washington, Oregon, Northern California

39. What type of aquifer is AQUIFER B

Confined

8. Which of the following mass movement processes has the slowest rate of movement?

Creep

29. Which of the following statements about meandering channels is true?

Cut banks are located on the outside of meanders

26. The amount of destruction caused by earthquake vibrations is affected by ________.

Design of structures, intensity and duration of the vibrations, and the nature of substrate all affect the amount of destruction caused by earthquake waves.

18. The position on Earth's surface directly above the earthquake source is called t

Epicenter

26. Moving from the headwaters to the mouth, in most streams, which of the following is true?

Flow velocity generally increases

34. ________ are characteristics found in all good aquifers.

High porosity and high permeability

30. ________ accounts for the largest percentage of groundwater usage in the United States.

Irrigation

3. Consider a weathered rock or soil particle lying on a slope. How will the gravitational force pulling the particle downward along the land surface vary with the inclination of the slope?

It will decrease as the slope angle is lessened (reduced)

14. Fractures in rock that do not involve slippage or offset along the fracture are called ________.

Joints

30. During ___________________, a near-surface layer of water-saturated sand changes rapidly from a solid to a liquid, causing buildings to "float" in earth.

Liquefaction

1. The downslope movement of rock, regolith, and soil is called ________. a. Weathering

Mass wasting

24. The ______________________ scale is a measure of the total energy released during an earthquake. It does not directly measure the extent of building damage.

Moment Magnitude

14. Which of the following statements concerning mudflows is NOT true?

Mudflows deposit talus slopes

7. What type of fold is this?

Overturned fold

37. ________ controls the ease (or difficulty) of groundwater transmission through a porous material.

Permeability

36. What term denotes the percentage of open space or voids in a material?

Porosity

20. ________ have the highest velocities (are the fastest)

Primary waves

22. A drainage pattern comprised of streams that diverge from a central area like spokes is called ________.

Radial

17. Unconsolidated granular particles assume a stable slope at the angle of _________.

Repose

12. What did this?

Rock fall

10. ________ denotes the exposed, crescent-shaped rupture surface at the head of a slump.

Scarp

27. ________ comprise the suspended loads of most rivers and streams.

Silt and clay-sized grains

7. ______________________ are the sudden failure of the slope resulting in transport of debris downhill by slumping, sliding, falling/rolling

Slope failures

Which type of mass movement involves a downward sliding mass of rock or unconsolidated material moving along a curved surface?

Slump

20. Which is the correct (geological) term for water that flows in a channel, regardless of size?

Stream

15. At the base of most cliffs is an accumulation of fallen material called ____________.

Talus

18. What event occurred in Lituya Bay, Alaska in 1958 as a result of an earthquake-triggered mass wasting event?

Tsunami

38. What type of aquifer is AQUIFER A?

Unconfined

25. ________ is the maximum possible damage designation on the Modified Mercalli

XII

32. The water table is ________.

a boundary between saturated rock below and unsaturated rock above

10. A graben is characterized by ________.

a hanging wall block that has moved down between two normal faults *

13. A thrust fault is best described as ________.

a low-angle (<45 degrees) reverse fault

6. Slopes that have been stable for many years may sometimes fail catastrophically. What is a common trigger for these failures?

addition of water to the slope (i.e. heavy rainfall)

5. Anticlines:

are upfolded or arched sedimentary layers

28. Seismic gaps are ________.

areas of Earth where earthquakes are not known to occur

Which of the following best defines strain?

change in rock's size, shape, or volume as a result of differential stress

27. The zone of greatest seismic activity on Earth is called the ________.

circum-Pacific belt

23. The distance between a seismological recording station and the earthquake source is determined from the ________.

comparing arrival times of P and S waves

19. Most of Earth's strongest earthquakes tend to occur along ________.

convergent plate boundaries (subduction zones)

25. The volume of water flowing past a certain point in a given unit of time is called ________.

discharge

Folds form as a result of ________.

ductile deformation

16. The mechanism by which rocks store and eventually release energy in the form of an earthquake is termed ________.

elastic rebound

17. When an earthquake occurs, energy radiates in all directions from its source. The source (within the earth) is also referred to as the ________.

focus or hypocenter

33. What term describes a stream which receives water through the inflow of groundwater through the stream bed?

gaining stream

4. All of the following are factors affecting mass movement EXCEPT for ________.

geologic age of rocks

23. The slope of a stream channel, expressed as the vertical drop of a stream over a specified distance (rise/run), is called the/a________.

gradient

2. The driving force behind all mass wasting processes is:

gravity

When water moves in nearly straight-line paths parallel to the stream channel in slow moving streams, this is called

laminar flow

31. The unsaturated zone ________.

lies above the water table

6. Tensional forces normally cause which one of the following?

normal faults

11. If you are standing facing a strike-slip fault, and movement of the crustal block on the opposite side is to your right, it is called a(n) ________ strike-slip fault

right-lateral

Which of the following mass movements is most likely to occur in a geologic setting where the rock strata are inclined?

slide

13. Which one of the following operates primarily in areas of permafrost?

solifluction

8. A(n) ________ fault has little or no vertical movements of the two blocks.

strike slip

21. On a typical seismogram, ________ will show the highest amplitudes.

surface waves (Love and Rayleigh waves)

22. Overall, this type of seismic wave is the most destructive. a. P waves

surface waves (Love and Rayleigh waves)

In thrust faulting, ________.

the crust is shortened and thickened

12. In a normal fault, ________.

the hanging wall block moves downward relative to the footwall block (footwall strata are "up" relative to hanging wall strata) *

29. S waves cannot travel through ________

the outer core (liquid)

21. Which of the following is located in the headwaters region (source) of a river system?

zone of sediment production