Lake Level Fluctuations of SUPERIOR-- EarthCache EarthCache
Lake Level Fluctuations of SUPERIOR-- EarthCache
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As an EarthCache there is no 'container' to find, instead you discover interesting things about the geology of the area.
To receive a 'find' for this cache you will need to e-mail me the answers to the following questions. PLEASE SUBMIT THE ANSWERS SOON AFTER YOU LOG THIS FIND SO THAT I CAN ID IT properly, otherwise I may need to delete it!
REQUIREMENTS:
1- You must visit (visit link) info=9087031+Holland,+MI (scroll down to third box, UNDER Great Lakes map click Lake Superior, then click blue DOT Marquette) and e-mail to my profile the current height for the lake level.( It is NOT 601.1) Look for 'observed height' number, which is above or below datum 601.1ft. LDW
2- What are the most obvious physical natural features nearby that show high watermarks in the past?
3- There are someones initals carved on the nearby large bolder. What are they?
4- What is the LARGEST river that feeds Lake Superior?
5- How far has the lake receeded from the high water marks?
6- What are the lake level differences between Lake Superior and Lake Huron?
Submit a pic if you wish.
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Lake Superior was formed during the Ice Age as glaciers moved from the north across the Great Lakes region. As the glaciers receeded large glacial lakes were formed.
Lake Superior is the largest of the five Great Lakes. It is also the largest fresh water lake in the world by surface area and the third-largest freshwater lake by volume.
Lake Superior rests mostly on Precambrian rock at the southern edge of the Canadian shield, the largest exposure of such bedrock on the planet.
HYDROLOGY:
Lake Superior empties into Lake Huron via the St Mary's River and the Soo Locks. It has a surface area of 31,820 square miles and a length of about 350 miles and a width of about 160 miles. Its average depth is 482 feet and in the deepest point 1,332 feet.
Lake Superior is not only the largest and deepest but also the coldest of the Great Lakes. The average temperature in the summer is 40 degres Fahrenheit.
Annual storms on Lake Superior regularly record wave heights of 20 feet, with 30 foot waves being recorded.
TRIBUTARIES AND OUTLETS:
The lake is fed by over 200 rivers. The largest include the Nipigon River, the St Louis River, the Pigeon River, the Pic River and the White River. It drains into Lake Huron by the St. Mary's River. The rapids on the river make it necessary for the Sault Locks, a part of the Great Lakes Waterway, to move boats down the 23.6 foot drop in elevation to Lake Huron.
WATER LEVELS:
The lake's average surface elevation is 600 feet above sea level.
Historic High Water - The lake fluctuates from month to month with the highest lake levels in October and November. The normal high water mark is 1.17 feet above datum (datum is 601.1 ft LWD.). In the summer of 1985, Lake Superior reached its highest level at 2.33 feet above datum.
Historic Low Water - the lake fluctuates from month to month with the lowest lake levels in March and April. The normal low water mark is .33 below datum (datum is 601.1 ft LWD.).
In the summer of 2007 monthly historic lows were set, August at .66 ft. and September at .58 ft
There is a tide but is is not noticable, but there is another water level fluctuation called a seiche, which can amount to about one foot. It is caused by the wind blowing, which piles water up at one end of the lake, lowering it at the other.
Water levels affect everyone from small boaters, marinas, commercial shipping and lakeside property owners.
CLIMATE Changes - Lake Superior water temperatures are increasing faster than the air temperature increases. Summer water surface temperatures have increased 4.5 degrees Fahrenheit, compared with an air temperature increase of 2.7 degrees Fahrenheit. This increase in water temperature may be related to a decreasing ice cover which allow more solor radiation to warm the water. This in-turn leads to more lake-effect snow.
*This is my 21st published EarthCache!
Great USA weather temp/map: (visit link)
Additional Hints
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