Frost Heave

The word of today in Headwaters Park is 'crunchy'.  Other than that sound, the Park was bundled in itself.  There was no detectable breeze; I heard no birds (unusual).  The only sound was my companion, Pete the dog, and clear crunches at each step.  This occurence is what many people in our region despise yet wait for each year:

FROST HEAVE!

According to the online Merriam Webster Dictionary, frost heave is ": an upthrust of ground or pavement caused by freezing of moist soil —called also frost heaving"  Frost heave is an annual occurence in our region, something developers, landscapers, farmers, and property owners need to think about each time earth is moved for construction, etc.  Frost heave, in the right conditions, will destroy roads, sidewalks, patios, any formerly stable, flat surface.  When it does not affect you, it's amazing.  When one is trying to drive along a paved road and is forced to navigate an obstacle course of potholes from frost heave, it's not too fun.  Check out the "dreaded pothole".

http://www.elkrivermn.gov/index.asp?Type=B_BASIC&SEC=%7B9959CBDF-95FB-47E8-82BC-DBA6D4C929B9%7D&DE=%7B74844E8F-6112-4E52-8A26-A263600706C2%7D

Also, frozen soil behaves like pavement.  Any runoff that ends up on frozen ground will not be filtered, but simply pick up speed as it races toward the nearest waterway, carrying any and every pollutant with it.  But having soil freeze also has benefits.

Frozen soil provides stability.  If soil is not frozen, yet waterlogged, you will get...MUD!  Mud happens, and when it happen occasionally it is manageable.  However, several months of mud can cause hazards for those that work outdoors with heavy equipment, such as farmers, tree trimmers, and landscapers.  Large animal farmers also need to consider how animals will adapt and stay healthy.   For example, wet conditions for a cattle farmer causes concerns for foot rot and general cleanliness of their product.  So, frozen soil can stabilize the ground, allowing for safer conditions for heavier equipment and animals.

Frozen soil also helps manage insect pests by keeping the egg and larvae population under control.  Many insects lay eggs in the soil in the hopes they survive until spring.  If the soil freezes to a depth that includes certain species eggs, the eggs will not survive.  From the other perspective, if there is a mild winter and little ground freeze, the insect population will boom the following spring, summer, and fall, making it unpleasant to be outside for some folks. 

Perhaps my favorite reason for ground freeze is the bulbs waiting underground.  So many varieties of beautiful spring flowers grow from hardy bulbs.  In the natural order of things, these bulbs need several months of cold temperatures to break them out of dormancy and produce stems, leaves, and flowers when the temperatures warm up a bit.  Without cold temperatures and frozen ground for them to wait under, these flowers would not emerge in the spring.  What a different spring that would be in this region!

Frost and frost heave have pros and cons.  But look how beautiful the ice can be!