Surface Water, Groundwater, and Karst Landscapes

Flashcards covering surface water dynamics, stream transport, groundwater features, geyser eruption stages, speleothem development, and karst topography.

How is a stream defined geologically?

A stream is any channelized flow of water, regardless of its size.

What are the three ways streams transport material?

As a dissolved load, as a bed load, and as a suspended load.

Which transport mechanism carries the majority of sediment in a stream?

The suspended load carries the majority of material, which also causes rivers to typically look muddy.

Where do the majority of rivers start and end?

The majority of rivers start in elevated areas called headlands and end at their mouth, where they meet the sea or another body of water.

What drainage pattern typically forms in headlands and what does it resemble?

A dendritic drainage pattern, which branches and looks much like the roots of a tree.

What is a perched water table?

A water table that develops above the primary zone of saturation in an area due to a relatively small layer of impermeable material.

What is a spring?

A naturally occurring flow of groundwater from the ground, formed when the water table or a perched water table meets the surface.

What is a spring-fed stream or spring-fed river?

A stream or river that receives most of its water from the ground rather than from precipitation.

What is the difference between an aquifer and a well?

An aquifer is a subsurface area that stores a significant amount of groundwater, while a well is a hole dug or drilled from the surface into an aquifer.

What gives the small hot spring in Yellowstone National Park, Wyoming its colors?

Different species of bacteria that live in the spring.

How frequently does Old Faithful in Yellowstone National Park erupt?

Every $35$ to $120$ minutes since its discovery in 1870.

What three geologic conditions are required for geysers to form?

Caverns must be present, groundwater must be plentiful, and heat from nearby magma must be sufficient to boil water.

What are the four basic stages of a geyser eruption cycle?

A) A cavern with a surface opening fills with groundwater; B) Heat from underlying magma boils the water; C) The geyser erupts and spews out essentially all water in the cavern; D) The cavern refills to restart the process.

How are caverns formed by groundwater?

Through the dissolution of limestone (calcite) by acidic groundwater, which forms when $CO_2$ from the atmosphere and soil dissolves in water to produce carbonic acid.

Under what condition do speleothems begin to form in a cavern?

When the water table drops enough for the cavern to become partially or completely filled with air, allowing minerals to precipitate rather than dissolve.

What are soda straws?

Small, tube-like speleothems that form on the ceiling of a cavern as calcium-laden water drips and releases $CO_2$.

What is the difference between stalactites and stalagmites?

Stalactites are elongated speleothems that grow down from the ceiling of a cavern, whereas stalagmites grow up from the floor.

What feature forms when a stalactite and a stalagmite meet?

A column.

What is flowstone?

A limestone deposit produced on the walls of a cavern as water trickles down them through degassing.

What is a sinkhole?

A natural depression formed by the collapse of a cavern's ceiling when the cavern grows too large to support overhead material.

What defines a Karst region?

A region composed primarily of limestone that features caverns, spring-fed streams, and sinkholes.

How can human activity promote the formation of sinkholes?

Through the construction of infrastructure and buildings in areas underlain by caverns and limestone.