how do lakes form and continue to exist?

Answer 1

See this site for the difference between lakes and ponds - http://www.aquahabitat.com/ponds.lakes.ed.html

ORIGINS OF LAKES and PONDS
Now that you have a rough idea of the difference between a pond and a lake, the next question is how did it get there?

Humans have lots of types of bulldozers and backhoes to build ponds and lakes with, but nature is the ultimate pond and lake builder. A huge bulldozer looks like a flea next to a glacier that is slowly carving and grinding away the land to form a lake. Some of the world's largest lakes, such as the Great Lakes in the United States, were formed from glaciers carving through the earth.

Glaciers carving down the side of a mountain will form large piles of debris which are called Moraines. Moraine Lakes form behind these debris piles.

Chunks of glaciers can also fall off the main glacier. When the climate warms enough to melt the ice, a Kettle Lake will form where the former ice was liquified.

Not all ponds need to be big. While a bulldozer and a backhoe may build big ponds, a person with a strong back and a hoe can build a small or even a tiny pond. You can build your own pond even as small as a mud puddle. Many people enjoy small ponds in their yards.

Nature may have the ultimate small pond builder called a beaver. While beaver ponds are small by natural standards, they are plenty big enough for people and wildlife to enjoy.

While many lakes are formed slowly by glaciers, others are built very quickly. Landslides can take less than a minute to form a dam that will back up huge lakes if the landslide crosses an existing river. Large earthquakes can form ponds and lakes due to sudden down-shifts in valley floors.

Even a forest fire can form a lake. There is a lot written about how lake succession where a lake fills in and becomes a marsh. A fire can turn a marsh back into a lake when all the decomposing vegetation that fills the lake catches fire. The peat material formed from decomposing vegetation will still burn. It can burn hot enough to dry out the lake and burn it deeper than the marsh that existed before the fire. This is one way forest fires play a very important role in maintaining natural environments.

Many lakes form slowly by moving one grain of sand at a time until a shallow lake basin forms. These are called Playa Lakes. They exist in very dry areas were the wind easily erodes the soil and sand. Playa lakes were a challenge to our Rate-a-Lake Key since they are more like a very large pond than other lakes. They are shallow; their temperature doesn't change much from top to bottom, and they usually are not fed or drained by a stream. They score as a lake because they can have tall waves during storms and a good sized playa lake will be deeper than twenty feet - but not always.

This same wind in a coastal sand dune area can form a pond quickly by blowing away loose sand.

Rivers can become lakes and lakes can become rivers when a river channel changes to isolate or abandon part of its former channel. These types of lakes are often called Oxbow Lakes since the part of the abandoned river channel is usually at a bend in the river.

Some of the most beautiful lakes were formed by volcanoes or volcanic action. Crater Lake in Oregon was called Mount Mazama until the mountain errupted about 7700 years ago and expelled so much rock and dust that the mountain simply collapsed.

A hot volcanic vent can come into contact with cool surface water to cause an explosion. The resulting crater is called a Maar. These can be some very pretty mountain lakes that give hints to their formation because they are fairly rounded in shape. Lava flows can also form lakes much like landslides will create a lake.

For more information go to this site - http://www.aquahabitat.com/ponds.lakes.ed.html

Answer 2

By defininition a lake is a collection of fresh water. Lakes get their water from a continuous source of fresh water,either a spring, melting ice, or a river. All fresh water lakes have an outflow that in a sense make the lake just a large slow flowing river. When the amount of water that comes into the lake equals the amount that exits the lake at the outflow plus the amount lost due to evaporation the lake will retain its size.

Answer 3

Lakes are formed due to natural or manmade impoundages and are subject to Residual Surplus Retention = Inflow - Outflow (Evaporation + Abstraction + Underground). Lakes exist until prevaling topographical, meteorological and geological conditions do not change although volumetric content will keep varying.

Answer 4

They are a low spot or hole type depression in the landscape that generally spring fed or fed by runoff, streams, or rivers. These are all fresh water sources ample enough to overcome evaporation rates.

Answer 5

They are typically feed through underground streams. Some come from larger water systems like rivers too.

Answer 6

".....All the rivers run into the sea; yet the sea is not full; unto the place from whence the rivers come, thither they return again."

From Ecclesiastes 1:4

Answer 7

they formed by Glaciers, many many many..... many years ago.

they continue because of evaporation and becauuse I said so.


:)