Five facts about ice
Posted by PA3 L. Laughlin, Tuesday, November 20, 2012
The 9th Coast Guard District reminds Great Lakes citizens and visitors to use extra precautions when planning recreational activities on frozen ponds, streams, rivers and lakes. Ice can be unpredictable and dangerous.
Ice is an ever-changing surface, and the fluctuating weather conditions affect the ice’s stability.
In an effort to prevent, prepare and educate those who recreate on the ice, here are five facts about ice:
1. Ice usually freezes from shore outward and new ice is stronger than old ice.
2. Direct freezing of lake water is stronger than ice formed from melting snow or refrozen ice
3. Obstruction such as rocks, logs, vegetation and pilings affect the strength of ice. Heat from these obstructions slows ice formation. Ice shifting and expanding will create pressure cracks and ridges around the obstructions.
4. Underwater streams or springs with flowing water will cause weak spots by keeping the water circulating, making any ice over or near moving water weak.
5. Ice near the shore of a frozen lake may be unsafe due to pressures outward and upward which cause cracks to appear. Ice closer to shore is weaker because of shifting, expansion, and sunlight reflecting off the bottom. This buckling shore ice continually thaws and refreezes.
In an effort to prevent, prepare and educate those who recreate on the ice, the Coast Guard would like to encourage people to remember the following tips:
I – Intelligence: check the weather and ice conditions, know where you are going, and know how to call for help/assistance.
C- Clothing: wear the proper anti-exposure clothes with multiple layers. If possible, wear a dry suit to prevent hypothermia, which can occur within minutes after falling through the ice.
E – Equipment: have the proper equipment such as a marine band radio, life jackets and screw drivers.