Topic 8 Lesson 3 Water Erosion
What are the shapes of delta
triangular, arc-shaped
As a river flows to the sea, it forms what other features?
waterfalls, flood plains, meanders, oxbow lakes
How does a delta form?
when a river no longer flows downhill into the body of water like lake or ocean, the water slows down. When the water slows down the sediment in the water drops to the bottom. The sediment deposited where a river flows into an ocean or lake builds up delta.
When a fast moving water starts to slow down and stop the rolling of larger rock and finer materials/sediments it can cause?
Water deposition which build up Earth's surface and produces land forms
How does a alluvial fan form?
When a stream flows out a STEEP, NARROW MOUNTAIN VALLEY, it suddenly becomes WIDER AND SHALLOWER. The water slows down and deposits sediment in an alluvial fan.
Explain how people use land can affect the amount of runoff
When people cut trees in the forest or everywhere and build more roads and house it can cause more runoff as there no more agent to hold the water.
can groundwater cause erosion
Yes, like moving water, ground water changes the shape of Earth's surface
What causes the erosion by water?
a little splash of rain
microscopic geochemical process
a single drop of water that dissolves a tiny amount of limestone in seconds
In meandering, where does the flow of water faster? a. shallow, inner section of each bend b. deeper, outer section of each bend c. deeper, inner section of each bend d. shallow, outer section of each bend?
b. deeper, outer section of each bend
Which can cause more runoff: a. heavy rain in 30 minutes b. heavy rain in 1 hour c. non-stop, small rain for 20 days d.showers for 2 days
b. non-stop, small rain for 20 days
Which of the following can cause more runoff: a. Heavy rain in amazon rainforest b. Heavy rain in San Francisco c. Heavy rain in the desert d. Heavy rain in landslide prone area
c. Heavy rain in the desert d. heavy rain in landslide prone area
What can be develop over time when acidic water flows into cracks in limestone and dissolves and carried away limestones or particles of limestones
caves or caverns
Oxbow lakes are the ________ of the ____________ ______________ bend.
remains, river bends
Arrange the following in order from smallest to biggest: streams, tributaries, gullies, rills, rivers
rills, gullies, streams, rivers tributaries
Some LANDFORMS result from erosion by what?
rivers, streams, deposition and/or combination of these processes
When the flood water finally retreats, it deposits _________ as new soil.
sediment
When runoff flows over the land, it can cause what type of erosion?
sheet erosion
How much can water shape the surface of the Earth?
small and large
The river receives water and sediment from a tributary - a smaller/larger river or stream that flows into it.
smaller
The sediment that deposits once the flood water retreats creates what types of soil
soil rich in nutrients
What do you call the deposit that hangs like an icicle from the roof cave
stalactite
What do you call the deposit on floor of the cave that looks like a cone-shape
stalagmites
Karst topography can form?
Deep valleys and Caverns
How does a waterfall form?
1. A river meets an area of hard, slowly eroding rock 2. The river flows over this rock and erodes softer rock downstream 3. Eventually a waterfall develops where the softer rock has worn away. 4. Rushing water and sediment can cause further erosion at the base of the waterfall. 5. Rough water rapids also occur where a river tumbles over hard rock, wearing away the supporting rock base and leaving the rock above it unsupported.
What are the 5 factors that can affect the amount runoff.
1. The amount of rain the area gets 2. Vegetation 3. Type of soil 4. Shape of the land 5. How people use the land
What is a delta?
A delta is a landform created by deposition of sediment where a river flows into an ocean or lakes
What is a meander?
A loop like bend in the course of a river
What is meandering?
A meandering river erodes sediment from the outer banks and deposits the sediment on the inner bank farther down the downstream. The water flows faster in the deeper, outer section of each bend, causing more erosion which cause meander to become more curved overtime
What is a sinkhole?
A sinkhole is the result of depression when the ROOF OF A CAVE COLLAPSES because of limestone erosion
What is karst topography?
A type of landscape in rainy regions where there is limestone near the surface, groundwater erosion which can SIGNIFICANTLY change the shape of the Earth.
How long will it take for groundwater to deposit calcite on the roof of a cave? And what's the measure?
After 100 years, groundwater might deposit 1 or 2 cm of calcite on the roof of a cave.
What is alluvial fans
Alluvial fan a type of landform that produced by water deposition. It is a wide, sloping deposit of sediment formed where a stream leaves a mountain range. It shaped like a FAN.
Explains what happens when a fast-moving water starts to slow down
Any time moving water slows, it deposits some of the sediment it carries. First, larger rock stop rolling and sliding as fast-moving water starts to slow down. Then, finer and finer particles fall to the river's bend as the water flows even more slowly.
Explain why wet areas, such as rain forest and wetlands, may have low runoff or erosion?
Because there are more plants to protect the soil
The Mississippi river is an example of what type of delta?
Bird's foot delta
How does carbonic acid changes the limestone form?
Carbonic acid becomes more acidic as it flows through leaf debris BEFORE it seeps into the ground. When the groundwater flows into cracks in limestone, some of the limestone dissolves and gets carried away which gradually hollows out pocket in the rock.
What is carbonic acid
Carbonic acid is a weak acid which is a combination of a rain water carbon dioxide that forms in the atmosphere. It can break down limestone.
How can the waves crashing against the rocks changes the shape of the land.
Crashing of waves against the rock changes the shape of the land because it causes water erosion. Water picks up and carries small sediment. And the force of the waves also increases the break downs of the sediment.
How does erosion by water happens?
During the rainfall, some water/rainfall sinks into the ground and absorbs by the plant roots, some water evaporates, and the rest of the water runs off over the land surface. When it runs off over the lands, it picks up and carries sediment
How long does it take for groundwater erosion.
EROSION might take THOUSANDS TO MILLION YEARS TO FORM a deep valley or huge cave system hundreds of kilometers long. The roof of a cave may very slowly erode over hundreds of years, but COLLAPSE WITHIN FEW MINUTES to form SMALL or LARGE SINKHOLES
Erosion by water __________________ particles on Earth's surface, while deposition by water __________________ it up
Erosion by water removes particles on Earth's surface, while deposition by water builds it up
In the desert, what do you think the amount of runoff in a little rainfall?
Even though desert have little rainfall, they often have high runoff and erosion because they have few plants and thin, sandy soil.
________________ also follow the meander as sediment erodes more of the land to the side of the river.
Flood plains
Explain how vegetation affects the amount of runoff
Grasses, shrubs, and trees reduce runoff by absorbing water. If there are more trees/plants it can reduce the amount of runoff.
Explain how the amount of rain affects the amount of runoff?
Heavier and lengthy rain produces more water therefore can cause more runoff; while small and shorter rain can produce small amount of water and therefore small runoff
What is the effect if the factors that reduce runoff increases to erosion?
If the factors that reduces runoff increases it will reduce erosion.
How can illegal logging (cutting of trees illegally) can affect the runoff and erosion?
Illegal logging can cause deforestation. When it happens less tress will protect the land/soil. Therefore, it will increase runoff as well as erosion.
What is Gullies? And how does it form?
It is a large groove, or channel, in the soil that carries runoff water after a rainstorm. It is formed when many rills flow into one another.
What is rills? And how does it form?
It is a tiny grooves in the soil that forms when runoff travels
Deep valleys and Caverns are types of landscape that called what?
Karst topography
Where does rivers begins?
Many rivers begin on steep mountain slopes as flowing rain water or melted snow. This running water starts out fast-flowing and generally follows a straight, narrow course. The steep slopes along the river erode rapidly, resulting in a deep, V-shaped valley.
What is the primary agent of the erosion that shaped Earth's land surface (geosphere) for billions of years?
Moving water of the hydrosphere (all water on Earth) is the primary agent of the erosion that shaped Earth's land surface.
What is a river and how does it form?
River is a larger bodies of flowing water that is formed as streams flow together.
What do you call small streams?
Small streams are called creeks or brooks
What are the two features that result from deposition by groundwater?
Stalactite and stalagmites
What is a stalactite?
Stalactite is a deposition that forms when carbon dioxide escapes from solution leaving a deposit of calcite. This deposit HANGS like an ICICLE from the ROOF of a cave.
What is a stalagmite?
Stalagmites is a CONE-SHAPED deposits that builds up as water drops from the cave FLOOR
Explain how different shape of land can affect the amount of runoff?
Steeper land can cause more runoff than latter land.
How would you describe stream formation?
Stream formation is cause gravity. Gravity causes runoff and the sediment it carries to flow downhill. As runoff moves across the land, it flows together to form rills, gullies, and streams.
What is streams? And how does it form?
Stream is a channel along which water is CONTINUALLY FLOWING DOWN A SLOPE. It RARELY DRY UP. Stream is formed when gullies join together.
How would you describe groundwater deposition
The action of carbonic acid on limestone can result in deposition. Water containing carbonic acid and calcium drips from a cave's roof. Carbon dioxide escapes from the solution, leaving behind a deposit of calcite.
What is a flood plain. What facts can you state about flood plain?
The flat, wide area of land along a river. During flood or a rainy season, a river overflows its banks and flows onto the flood plain. As flood water retreats, it deposits sediment which gradually makes the soil of a flood plain rich in nutrients.
How does groundwater cause erosion?
Through chemical weathering
What is a tributaries? Give an example.
Tributaries is a stream or river that flows into a larger river. Missouri and Ohio rivers are tributaries of the Mississippi River.
Which area can have little runoff: a. Small rain in the desert b. Heavy rain in rain forest c. Small rain in deforested mountain d. Small rain in a farm
d. small rain in a farm
What types of landforms are formed from water deposition
deltas, alluvial fans
An oxbow lake is a meander cut off from the river by deposition/erosion of sediment
deposition
The action of carbonic acid on limestone can also result in __________
deposition
Flood plain forms where the river's power of deposition/erosion widens it valley rather than deepening it.
erosion
The water flows ________ in the deeper, outer section of each bend, causing more ________ which cause meander to become more _________ overtime
faster, erosion, curved
Waterfalls and rapids are common where the river passes over softer/harder rock
harder
What statement is correct regarding the formation of Karst topography? a. the formation of karst topography happens over large area for a long time period. b. the formation of karst topography happens over small area for a long time period. c. the formation of karst topography happens over large area for a short time period. d. the formation of karst topography happens over small area for a short time period. e. the formation of karst topography happens over small and large area for a short time period. f. the formation of karst topography happens over small and large area for a long time period. g. the formation of karst topography happens over small area for a short or long time period. h. the formation of karst topography happens over large area for a short or long time period. i the formation of karst topography happens over small or large area for a short or long time period.
i. the formation of karst topography happens over small or large area for a short or long time period.
Where does groundwater come from?
is the term used by geologist to the water that came from rain falls, snow melts that soaks into the ground, trickles into cracks and spaces in layers of soil and rock
What is sheet erosion
is the type of erosion when runoff flows over the land where THIN LAYERS OF SOIL ARE REMOVED.
How does a oxbow lake form?
it forms when a meander develops a large loop that bends of the river join together. Sediment deposits block the ends of the bends, cutting off the river flow.
Explain how different types of soil affects the amount of runoff
loamy soil can hold more water than the sand. Therefore, the sand can cause more runoff water.
Groundwater erosion starts with a _____________ ______________ _______________
microscopic geochemical process: a single drop of water that dissolves a tiny amount of limestone in seconds.
What does runoff means?
moving water