### formation:

Sinkhole
* Most sinkholes are relatively small.
* Some sinkholes are big enough to swallow vehicles and buildings
  - develop naturally
  - form in thick layers of homogenous limestone
  - give way gradually and are filled in with dirt or sand from above
  - lead into underground springs, resulting in the formation of sinkhole ponds
* accumulate rusting appliances as if drawn by a magnet.
* act like funnels, collecting rain water from the surface and funneling it into the cave.
* also form by the weathering and dissolving of surface carbonate rocks
  - occur in sandstone and quartzite terrains
  - play an important role in connecting groundwater and surface water
* appear all over the United States.
* are caverns
  - closed depressions found on land surfaces underlain by limestone
* are common features of the Red Hills region
  - in Florida where they're often caused by the loss of groundwater from pumping
* are depressions or holes in the land surface that occur throughout west central Florida
  - that form when a portion of the lithosphere below is eroded away
  - direct connection to our groundwater through cracked and crevice limestone
  - found all over the world
  - hazardous because they can destroy highways and buildings
  - perhaps the most common surface expression of underlyng caves
  - probably the worst place to put trash
  - subsidence or collapse features that form at points of local instability
  - the result of differential subsidence of the land surface
* can also form when the land surface is changed.
* can be as small as a meter across or as large as a big lake
  - deadly
  - natural or man made
  - collapse catastrophically with dramatic damage to property
  - develop unexpectedly and rapidly, swallowing up cars, houses and whole towns
* can form anywhere there is soluble rock present underground
  - for a variety of reasons
* come in all sizes, some only a few feet across.
* develop when seeping water dissolves soil and rock under the road.
* have important effects on both surface and ground water
  - low densities
* occasionally make the news by swallowing buildings, roads, and trucks.
* occur when there are changes in the water table.
* often form through the process of suffosion.
* serve as direct entrance for surface water to the groundwater system.
* tend to occur in karst landscapes.
* vary in shape and size.

### formation | sinkhole:

Natural sinkhole
* can also form due to heavy rainfall and droughts
  - form on land and in the ocean as well
* occur due to erosion or underground water.

Slope
* are located in roofs
  - rates of change , a fundamental idea of calculus
* can affect the centricity of tree ring formation.
* describe how fast the curve given by graphing one quantity versus another, rises and falls.

### formation | slope:

Camber
* are alignment.
* distinguishes cross-country skis from downhill skis.
* refers to the amount of curve across the top of the wing.

### formation | slope | camber:

Negative camber
* is when the top of the tire leans toward the center of the vehicle.
* occurs when's the tops of the tire are leaning toward the vehicle.

Escarpment
* are fortification
  - slopes
  - walls
* erode gradually and over geological time.
+ Titania (moon), Physical characteristics, Surface features: Uranus' moons
  * Escarpments here are called rupes. They are named after the places where plays by Shakespeare happen.