2 April, 2002

Weather

Weather: Sunny
High 28
Low -2

Deaf Luncheon

Today, I stayed inside working on data calculations. For lunch, we joined a group of approximately 15 Deaf and Hard of Hearing residents for their Tuesday lunch gathering at the Deaf center. The Deaf community in Fairbanks is quite small compared to Portland. The Science Behind Ice Fractures

Ice is a solid form of water at freezing point (0 šC or 32 šF). At this time of year, ice will react to temperature changes by expanding at warmer temperatures and contracting at colder temperatures. Air temperatures during the day is just above freezing point, whereas still below freezing at night. This brings us to 2nd of 4 phase of this research study.
Phase 1: Below freezing all day, all night
Phase 2: Above freezing all day, below freezing all night
Phase 3: Above freezing all day, all night
Phase 4: No snow cover

On frozen ponds, human disturbance and snow depth increase ice stress. Snow is quite heavy causing a lot of strain on ice. Ice will eventually crack and water will seep through flowing into the bottom of the snow cover. Over some time, slush will freeze adding a new layer of ice on the surface

For Phases 1 through 3, we take our usual measurements to calculate heat flux as well as ice thickness. Without any snow in Phase 4, we only measure ice thickness to determine melting process (ice decay). See below samples of ice fractures.

1. Ice fracture on Jalpertia pond

2. & 3. Stress fractures

3.

4. For every transect, we use either wooden posts or plexiglass tubes (pictured above) as a marker for every 5 meters. These transparent tubes have similar properties to ice and will not progress ice decay around the tubes. In Phase 4, ice surface will be marked on plexiglass tubes to observe ice decay.