Landforms

Question 1

Rock Falls

Answer 1

Individual pieces of rock fall independently and form a cone-shaped pile or irregular broken rocks in a talus slope at the base of a steep incline, where several talus cones coalesce. Instantaneous and fast. From exposed rock. Controlled by rock strength/weathering.

Question 2

Talus

Answer 2

Repeated rock falls will accumulate at bottom of cliff in piles called talus or scree

Question 3

Talus Cone

Answer 3

Where rockfall are concentrated below drainages called chutes

Question 4

Landslides

Answer 4

Sudden rapid movement of a cohesive mass of regolith or bedrock that is not saturated with moisture.

Question 5

Mudflow/Debris flow

Answer 5

Created by excessive water, but picks up more material and flows like a fluid, potentially moving large particles (boulders). Transporting material a great distance down slope. Can transport tremendous amount of material. Center of debris flow moves faster than sides

Question 6

Debris Flow Levees

Answer 6

Created when larger debris is deposited along margins in piles

Question 7

Creep

Answer 7

Water gets into soil–>soil expands and rises–>gravity pulls down objects. Slow and dry. Any slope has some amount of creep. Ground swells up when it rains, swells more when clay is in soil

Question 8

Solufluction

Answer 8

Saturated soil flowing down slope, held in place by turf (grass). Often over permafrost. Tundra and wet meadows. Solifluction lobes move like conveyer belts. Soliflucture lobes look like oozing with grass over it. Slow.

Question 9

Scarp

Answer 9

Newly exposed material. Top of slide. Crescent shaped facing downslope

Question 10

Hummocky topography

Answer 10

Steep sided hillock(s) and hollow(s) with multidirectional slopes dominantly between 15 and 35° (26 to 70%) if composed of unconsolidated materials; bedrock slopes may be steeper.

Question 11

Debris Flow

Answer 11

Saturated or near saturated sediment involved. Lots of water and very fast. Rock debris tumble like a landslide, but because of water the body of the slide is like a fluid. When associated with volcanic material called lahar. Material mx of water and sediment. Particle sizes larger than just water. Potential to transport very large particles.

Question 12

Fluvial

Answer 12

Humans most important process shaping Earth’s surface. Action of flowing water.

Question 13

Runoff

Answer 13

Water flowing over surface. 3/8 total precip that falls on earth is carried seaward by streams as runoff. 5/8 evaporates or infiltrates. Depends on seasonality, soil saturation, snow vs. rain, relief, bedrock and soil (unconsolidated sediments and soils absorb more water than rock, vegetation coverage, evaporation, groundwater interactions: lotic (effluent) (lake,wetland) vs. lentic (influent, stream,flowing water)

Question 14

Watersheds

Answer 14

Natural subdivision of the landscape. All water in one area goes the same place.

Question 15

Confluence

Answer 15

Where two rivers merge

Question 16

Baselevel

Answer 16

Non-moving water. When stream hits base level (non-moving water) it deposits its sediment in transport in the delta

Question 17

Hydrographs

Answer 17

Graphs showing discharge over time

Question 18

Alluvium

Answer 18

Fluvial deposits

Question 19

Discharge

Answer 19

Amount of water flowing past a given place at a given time, measured in m 3/s or

Question 20

Mannings Equation

Answer 20

Calculates velocity of a stream

• r=hydraulic radius- channel size (bigger channels, larger volumes of water go faster)
• s=slope- bigger slope, water goes faster
• r=roughness-rougher channels, slows water down, smooth bed allows water to go faster

Question 21

Four controls on stream velocity: Slope

Answer 21

• slope, stream gradient (s), at headwaters of mt. stream gradient is steep
• no gradient: clay sized
• low gradient: low energy, sand and silt
• moderate gradient, moderate energy, coarse sand
• high gradient, high energy, coarse gravel

Question 22

Four controls on stream velocity: Channel shape

Answer 22

-important for friction which decreases velocity
-hydraulic radius ® is defined as R=A/P
which is a measure of efficiency of moving water through the channel

Question 23

Four controls on stream velocity: Discharge

Answer 23

• amount of water flowing past a given place at a given time measured in m 3/s
• Discharge= Q= WDV
• combining this with Mannings equation allows discharge to be estimated by measuring simple channel measurements

Question 24

Four controls on stream velocity: Channel roughness

Answer 24

• the more irregular- vegetation, rocks, bridge footings, etc. (roughness elements) the more contact area and slower the flow
• the more turbulence that is introduced slows the flow

Question 25

Floating sediment

Answer 25

Dust/logs that fall on the surface

Question 26

Dissolved load

Answer 26

Ions and molecules from weathering

Question 27

Suspended load

Answer 27

Clay/silt size particles that are in suspension and do not settle out

Question 28

Bedload

Answer 28

Larger particles that are never truly in suspension (saltation, creep and rolling)

Question 29

Relation of stream velocity to erosion and sediment transport

Answer 29

Higher velocity flows transport away smaller particles leaving only larger particles to be deposited

• going so fast da small sediments get whipped all the fuckin way down, only the large get deposited
• slower velocity flows leave smaller particles
• clay: slack water: low energy
• sand: low velocity flow: low energy
• gravel: moderate velocity flow: high energy
• cobbles/boulders: high velocity flow: high energy flood events

Question 30

Pools and riffles

Answer 30

Rhythmically spaced every 5/7 channel widths. Riffles and bars alternate side to side. Large woody debris create more pools (step-pools). Occur on moderate-gradient slopes. Most common on lower order (smaller) streams

Question 31

Meandering streams

Answer 31

Curving channel. Measured by sinuosity-river length/straight line length. (How far it goes around line of best fit) Typically has well defined vertical banks and floodplain. Occur on low-gradient slopes. Sinuosity often increases as gradient decreases, goes out further as it gets flatter. Happenz in flat landz.

Question 32

Sinuosity

Answer 32

River length/straight line length, how far it goes around line of best fit. Often increases as gradient decreases (goes out further as it gets flatter)

Question 33

Braided streams

Answer 33

Nooksack. Multiple channels with mid-channel bars. Often the result of excessive sediment delivery to stream (glacial basins). Occur on low-gradient slopes. Deposition (bars/braids) increase as gradient decreases

Question 34

Karst

Answer 34

Terrain with distinctive landforms and drainage arising from greater rock solubility in natural water. Often associated with limestone, but in other rocks as well. Looks rounded with holes. Susceptible to chemical weathering leaving it with bumpy topography, poor surface drainage, well developed solution channels underground & 38% of Kentucky is Karst lolz.

Question 35

Carbonation Solution

Answer 35

CHemical weatherng occurs when minerals dissolve into solutions. Water is a universal solvent, dissolving 57 minerals. Water vapor dissolves carbon dioxide, yielding precipitation high in carbonic acid. The acid can dissolve limestone like a motherfucker.

Question 36

Dolines (sinkholes)

Answer 36

Circular depressions where limestone weathered away.

Question 37

Tower Karst

Answer 37

Resistant cones and towers in limestone beds that don’t collapse

Question 38

Speleothems

Answer 38

study of caves

stalactites grow from ceiling, stalagmites grouw from ground