Function

Because ice roads are flat, devoid of trees, rocks and other obstacles, they have a smooth driving surface. They are largely plowed across frozen lakes, with a short overland portage between the shoreline of one lake and the next. Similar to ice roads, ice runways are common in the polar regions and include the blue ice runways such as Wilkins Runway in Antarctica or lake ice runways like Doris Lake Aerodrome in the Arctic. Ice is used as an emergency landing surface.

In general, these roads are built in areas where construction of year-round roads is expensive due to boggy muskeg land. When frozen in winter, these obstacles are easier to cross. Ice roads such as the stretch between Inuvik and Tuktoyaktuk, Northwest Territories, Canada provide an almost level driving surface with few detours several months of the year.

Ice roads and winter roads are used where year-round roads are expensive or impractical. When frozen in winter, the waterway crossings can be built up with auger holes to flood and thicken the crossing. Clearing snow (which insulates and warms) makes ice thicker, more quickly. These seasonal links last anywhere from a few weeks to several months before they become impassable.

After an ice road is plowed across a lake, the ice there gets much thicker than the surrounding lake ice, because the snow cover is swept off — exposing the road directly to subfreezing air (temperatures as low as −50 °C (−58 °F)). When a lake thaws in the spring, the ice under the road is the last to melt, and in the summer, traces of the roads can still be seen from overhead in a bush plane, as bare strips remain on the lake floor where the ice blocked light and prevented plants and algae from growing.

### Other articles related to "function":

Integral - Extensions - Multiple Integration
... In general, an integral over a set E of a function f is written Here x need not be a real number, but can be another suitable quantity, for instance, a vector in R3 ... Just as the definite integral of a positive function of one variable represents the area of the region between the graph of the function and the x-axis, the double integral of a positive function of two ... The same volume can be obtained via the triple integral — the integral of a function in three variables — of the constant function f(x, y, z) = 1 over the above mentioned region between the surface and ...
Integral - Fundamental Theorem of Calculus
... are inverse operations if a continuous function is first integrated and then differentiated, the original function is retrieved ... fundamental theorem of calculus, allows one to compute integrals by using an antiderivative of the function to be integrated ...

### Famous quotes containing the word function:

Advocating the mere tolerance of difference between women is the grossest reformism. It is a total denial of the creative function of difference in our lives. Difference must be not merely tolerated, but seen as a fund of necessary polarities between which our creativity can spark like a dialectic.
Audre Lorde (1934–1992)

Philosophical questions are not by their nature insoluble. They are, indeed, radically different from scientific questions, because they concern the implications and other interrelations of ideas, not the order of physical events; their answers are interpretations instead of factual reports, and their function is to increase not our knowledge of nature, but our understanding of what we know.
Susanne K. Langer (1895–1985)

The function of literature, through all its mutations, has been to make us aware of the particularity of selves, and the high authority of the self in its quarrel with its society and its culture. Literature is in that sense subversive.
Lionel Trilling (1905–1975)