Kettle (landform)

A kettle (or kettle hole) is a shallow, sediment-filled body of water formed by retreating glaciers or draining floodwaters.

Overview

. [Tarbuck, E and Lutgens, F:Earth, page 351. Prentice Hall, 2002]

Kettle holes can also form as the result of floods caused by the sudden drainage of an ice-dammed lake. These floods, called Jokulhlaups, often rapidly deposit large quantities of sediment onto the sandur surface. The kettle holes are formed by the melting blocks of sediment rich ice that were transported and consequently buried by the Jokulhlaups. It was found in field observations and laboratory simulations done by Maizels in 1992 that ramparts form around the edge of kettle holes that are generated by Jokulhlaups. The development of distinct types of ramparts depends on the concentration of rock fragments contained in the melted ice block and on how deeply the block was buried by sediment. [ Bennett, M and Glasser, N:Glacial Geology: Ice Shetts and Landforms, page 267. John Wiley and Sons, 1997]

Most kettle holes are no larger than 2 kilometers in diameter, although select kettles in the midwest of the United States have exceeded 10 kilometers. Puslinch Lake in Ontario, Canada, is the largest kettle lake in Canada spanning 160 hectares (380 acres) and is a common recreational destination. Fish Lake in the North Central Cascade Mountains of Washington State, U.S.A., is 200 hectacres (~550 acres). [Schmuck and Peterson, 2002 Warmwater Fisheries Survey of Fish Lake, Chelan County, Washington, page 1, State of Washington, 2005]

Also, the general depth of most kettles are less than 10 meters. [Tarbuck, E and Lutgens, F:Earth, page 351. Prentice Hall, 2002] In most cases kettle holes eventually fill with water, sediment, or vegetation. If the kettle is fed by surface or underground rivers or streams it becomes a kettle lake. If the kettle receives its water from precipitation, the groundwater table, or a combination of the two, it is termed a kettle pond or kettle wetland, if vegetated. Kettle ponds that are not affected by the groundwater table will usually become dry during the warm summer months, deemed ephemeral. [http://www.slackpacker.com/glacial.html]

If water in a kettle becomes acidic due to decomposing organic plant matter, it becomes a kettle bog or kettle peatland, if underlying soils are lime-based and neutralize the acidic conditions somewhat. Kettle bogs are closed ecosystems because they have no water source other than precipitation.

Both acidic kettle bogs and fresh water kettles are important ecological niches for some symbiotic species of flora and fauna [http://www.kmoraine.com/interest.htm] .The Kettle Moraine is a region of Wisconsin, covering an area from Green Bay to south-central Wisconsin, and has numerous kettles, moraines and other glacial features. It has many kettle lakes, some of which are 100 to 200 feet deep. Kettle Point, Ontario, a First Nation community on Lake Huron in Ontario, Canada has many examples of kettles, hence the name.

Pothole lakes dot the landscape of the Northern Hemisphere in the American and Canadian prairies, the Russian steppes, and throughout northern Siberia. Some of these lakes are far from agricultural land and settled areas, so they have fairly clear and unpolluted waters. Scientists use satellite images of these glacial kettle lakes to measure water clarity and to make environmental assessments. Scientists also monitor these lakes to study climate change. Researchers reported in "Science" that over the past 30 years, some glacial kettle lakes in northern Siberia have drained as the region has warmed and the permafrost beneath the lakes has "cracked," allowing lake water to drain out.

In September 2008 workers preparing a new foundation at the World Trade Center site discovered a deep pothole. [ [http://www.nytimes.com/2008/09/22/nyregion/22rocks.html?_r=1&em&oref=slogin NY Times] WTC glacial discovery ]

Examples of kettle lakes

*North America
**Canada
***Kettle Point
***Lake Wilcox
**New England
***Walden Pond
***Jamaica Pond
***Ell Pond
***Fresh Pond
***Spruce Hole Bog
**Long Island
***Lake Ronkonkoma
**Michigan
***Heart Lake
***Thumb Lake
**Ohio
***Stage's Pond State Nature Preserve
**Wisconsin
***Elkhart Lake
***Mauthe Lake
**Iowa
***Clear Lake
**Washington
***Fish Lake
**Ontario
***Puslinch Lake.

ee also

*Glacial landforms

References

*http://www.slackpacker.com/glacial.html
*http://www.kmoraine.com/interest.htm
*http://wdfw.wa.gov/fish/warmwater/library/fpt05-11.pdf
*http://zeitcam.com/showcam.php?cam=fishlake&current

External links

* [http://www.cr.nps.gov/history/online_books/science/2/chap4.htm Geology of Ice Age National Scientific Reserve of Wisconsin NPS Scientific Monograph No. 2]
* [http://www.geology.wisc.edu/~davem/abstracts/05-7.pdf The genesis of the northern Kettle Moraine, Wisconsin - PDF]
* [http://www.apa.state.ny.us/About_Park/geology.htm Geology of the Adirondack Park]
*cite web | url=http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=17099 | title=Pothole Lakes in Siberia | publisher=NASA Earth Observatory | accessdate=2006-05-02