General Information
A “kettle lake” or kettle hole is a shallow, sediment-filled body of water most commonly formed by retreating glaciers or draining floodwaters. Near the mountains, kettles are generally glacial landforms occurring as the result of blocks of ice breaking off (or calving) from the front of a receding glacier and becoming partially to wholly buried by material that is carried by glacial outwash. Glacial outwash is generated when streams of meltwater flow away from the glacier and deposit sediment to form broad outwash plains called sandurs (somewhat similar to "deltas" that form at the end of rivers). When the ice blocks melt, voids are left behind in the sandur. If these voids fill up with water, they are called kettle lakes. Otherwise, they are usually called kettle holes.
While most kettle lakes are typically less than two kilometres in diameter, some kettle lakes have been found to exceed ten kilometres. The largest kettle lake in Canada is Puslinch Lake in Ontario, Canada, spanning 160 hectares (400 acres). Kettle lakes are typically quite shallow, with most of them being less than 10 metres in depth. (Source: Wikipedia)
Kettle lakes are just one of many different types of glacial landforms that can exist. A few of the other common landforms that are created by glaciers include: eskers, drumlins, kames and terminal moraines.
This Earthcache
From this location, you will have a great vantage point of a small kettle lake located within Bow Valley Provincial Park. Compared to most, this kettle lake is quite small in size, being only ~100 meters in diameter.
Locally known as "Middle Lake", this kettle lake was formed with the retreating of the Bow Valley Glacier. As the glacier retreated, it also left behind a ridge of rock debris (called a terminal moraine) which can be seen just to the west as you look across the far side of Middle Lake.
At the posted coordinates, you will be on a small lookout that sits above Middle Lake. Parking is located ~50 metres away, and there are park-maintained outhouses and garbage facilities located right beside the parking area. While this Earthcache is technically not wheelchair accessible, the path to GZ is quite gentle with a slight incline over the last ~5-10 metres.
While most Earthcaches explain how an interesting geological feature is created, this Earthcache is intended to also highlight how a geological feature can "die" over time. There is also an interpretive sign located at GZ which will teach you more about how this particular kettle lake was formed, as well as the likely future demise of Middle Lake.
While you are in the area, be sure to check out some of the other geocaches that have been placed nearby.
Logging Requirements
To log this earthcache, e-mail answers to the following questions to the cache owner to authenticate your online log. Do not post the answers online. All answers to the logging questions can be found using the interpretive sign at the posted coordinates.
#1) As compared to most kettle lakes which are already quite shallow, Middle Lake is especially shallow. What is the typical depth of Middle Lake? Is the lake deep enough to support fish? (Hint: found on the 4th panel)
#2) What are some of the types of vegetation that can be found growing around the edges of Middle Lake? (Hint: found on the 4th panel)
#3) The interpretive sign describes that Middle Lake is slowly disappearing. In your own words, explain the process that is happening here that will ultimately lead to the demise of Middle Lake.
#4) (Optional) Feel free to post a photo of yourself at Middle Lake. (In order to prevent "armchair earthcaching", please ensure that the interpretive sign is not in the photo.)
Websites for additional information
https://en.wikipedia.org/wiki/Kettle_(landform)
https://en.wikipedia.org/wiki/Fluvioglacial_landform