Factors Effecting Ice Strength

Question 1

Water reaches its maximum density at ___

Answer 1

4°C

Question 2

After ice reaches its maximum density on cooling, it ___

Answer 2

Expands until frozen at 0°C

Question 3

The hydrogen atoms in H20 molecules bond to form ___

Answer 3

Hexagon-shaped crystals, leaving more spaces between them

Question 4

Ice expands about ___

Answer 4

9%

Question 5

Strength and thickness can vary considerably from one ___

Answer 5

Location to another

Question 6

Ice seldom freezes and thaws at a ___

Answer 6

Uniform rate

Question 7

Pure water freezes ___ than water with impurities or pollutants

Answer 7

Faster and deeper

Question 8

Pollutants cause ___ and interfere with ___

Answer 8

Melting

Strong ice formation

Question 9

Fluctuating water levels can ___

Answer 9

Weaken ice

Question 10

Causes of fluctuating water levels

Answer 10

• Rain
• Seepage from cracks
• Lake levels
• Flooding caused by ice jams
• Wind seiches

Question 11

Lower water levels ___

Answer 11

Weaken ice

Question 12

Ice without water underneath will ___

Answer 12

Crack underfoot

Question 13

Decaying ice does not melt to a ___

Answer 13

Thin sheet

Question 14

Decaying ice becomes ___

Answer 14

Dangerously porous

Question 15

Decaying ice takes on a ___ appearance

Answer 15

Dark

Question 16

Pools of water on the surface of ice can ___

Answer 16

Accelerate deterioration

Question 17

Obstructions affect ice ___

Answer 17

Strength

Question 18

___ from obstruction slow ice formation

Answer 18

Heat

Question 19

Decomposing vegetation generates ___

Answer 19

Heat

Question 20

Ice shifting and expanding will create ___ around the obstructions in the water

Answer 20

Pressure cracks and ridges

Question 21

Ice ___ with air temperature fluctuations

Answer 21

Expands and contracts

Question 22

Soft ice or open water areas often occur near ___

Answer 22

Pressure ridges

Question 23

The booming sound you may hear on cold days occurs when ___

Answer 23

The ice sheets are expanding and change shape with the change in the air temparature

Question 24

Strong winds create ___ that can slow ice growth

Answer 24

Moving water

Question 25

Moving ice collides to form ___

Answer 25

Windrows and Rubble

Question 26

Wind can detach ___

Answer 26

Large ice floes and strand ice travelers

Question 27

Winds move ___

Answer 27

Ice floes and plates

Question 28

Snow can ___ strong ice and ___

Answer 28

Insulate

Prevent ice from melting

Question 29

Snow can ___ the surface against ___

Answer 29

Insulate

Freezing

Question 30

Snow can cause ice to ___ or ___

Answer 30

Form slowly

Deteriorate the ice it sets upon

Question 31

Snow’s weight can ___

Answer 31

Depress an ice sheet

Question 32

Snow can cover ___

Answer 32

Danger signs of hazardous areas

Question 33

Snow cover on ice is sometimes referred to as ___ by ice fishermen

Answer 33

The Devil’s Blanket

Question 34

___ affect ice strength over moving streams

Answer 34

Currents and velocity

Question 35

River is usually ___% weaker than lake ice

Answer 35

15

Question 36

Straight stretches of river ice are ___ than at bends in the river, due to ___

Answer 36

Stronger

Slower currents found in the straight stretches

Question 37

Currents ___ the ice from underneath

Answer 37

Erode

Question 38

River mouths are ___

Answer 38

Dangerous

Question 39

Measure to reduce risk when operating in areas where current is present

Answer 39

• Additional personnel and supervision
• Additional equipment (SKF-ICE, ice staff, tending lines)
• Assistance from local SAR partners