Note: This is an Earthcache. There is no physical cache to find. Logging this Earthcache requires that you undertake an educational task relating to the specific Earth Science at the site.
Prior to logging this cache, click on Message this owner, or send an email with answers to the following questions:
- What evidence can you notice that the lake’s water level has risen rapidly?
- Do you think the land at GZ is in danger of becoming submerged?
- Required to log this cache: Please provide a photo of yourself or a personal item in the picture to prove you visited the site. Upload the photo with your log.
Geology
Devils Lake is North Dakota’s largest natural lake. It formed in a depression that was excavated by glaciers about 10,000 years ago.
(a) and (b) As the glaciers advanced, they overrode the saturated sediments that had filled the Cannonball River Valley.
(c) The weight of the advancing glaciers increased ground-water pressure in the Cannonball River Valley sediments, and the overlying material was lifted up into the advancing glacier.
(d) An excavated depression was created. The glaciers then pushed or thrust the material a few miles to the south-southwest. The excavated depression now is occupied by Devils Lake, and the material thrust to the south-southwest is known as Sully's Hill.
Devils Lake is a closed lake. There are no streams or rivers flowing out of the lake. It only overflows into the Sheyenne River when it reaches 1,458 feet. The Sheyenne River is a tributary of the Red River, which flows north into Canada. Devils Lake has reached its spill elevation of 1,458 feet and overflowed into the Sheyenne and Red Rivers at least twice during the past 4,000 years. The last Devils Lake spill into the Sheyenne River occurred less than 2,000 years ago.
In March 1993, Devils Lake had an elevation of 1422.62 feet and a surface area of 44,230 acres. At its June 2011 elevation, Devils Lake had a record elevation of 1454.3 feet and covered about 211,300 acres – an increase of 167,070 inundated acres, or about 261 square miles. During that same time period, the volume of water in Devils Lake had grown by more than seven times.
The reasons for the fluctuations may be attributed to the underlying Spiritwood Aquifer. During long spells of precipitation the aquifer may become full and overflow into the lake, raising the water level. During periods of drought the aquifer may not be fully charged and the lake water may flow into the aquifer. Precipitation after a drought may not immediately raise the lake’s water level until the aquifer is full. Ultimately, the changes of water-level at Devils Lake result from long-term climatic events.
The city of Minnewaukan, which is west of Devils Lake, continues to be threatened by the rising water, in spite of additional levee construction and pumping efforts by the U.S. Army Corps of Engineers (USACE).
The name "Devils Lake" is an approximate translation of its Lakota name, Ble Waka Sica ("blay wah-kahn shee-chah"; literally: "Lake of the Spirits").
Source: http://nd.water.usgs.gov/devilslake
