9 Matching Annotations
  1. Mar 2019
  2. Jan 2019
  3. Mar 2018
  4. Jan 2018
  5. May 2017
    1. Frost Bulb
      Hugh M. French, a member of the department of geography at the University of Ottawa, states that “nowhere has the frost heave problem been more critical than in the recent design of proposed chilled buried gas pipelines in Arctic regions” in his article entitled “Periglacial Geomorphology in North America: Current Research and Future Trends.” These chilled buried gas pipelines must function under extremely harsh conditions. They will be exposed to sub-zero temperatures in Arctic regions. Any water and vapor will “migrate towards the pipe” causing a frost bulb to form. This frost bulb will lead to the formation of an ice lens or numerous ice lenses which will cause frost heave around the chilled buried pipe (French, 1987). There are currently many techniques to attempt to predict the behavior of a buried pipeline that experiences frost heave. One such attempt to describe this phenomenon was proposed by Selvadurai and Shinde, both members of the American Society of Civil Engineers, in which they describe a detailed model of a frost heave zone caused by its associate frost bulb. They base their model off of the “heave of a frost bulb zone that develops around the pipeline as it transmits its contents such as chilled natural gas” (Selvadurai & Shinde, 1993). 
      

      References

      French, H. M. (1987). Periglacial Geomorphology in North America: Current Research and Future Trends. Ecological Bulletins, 5-16. Selvadurai, A. P., & Shinde, S. (1993). Frost Heave Induced Mechanics of Buried Pipelines. American Society of Civil Engineers, 1929-1951.

    2. frost heave
      Before the understanding of frost heave, there was a widely held belief that rocks and stones could grow and multiply. Stones were believe to grow from small pebbles. These stones then rose to the surface of the ground. Another belief was that stones were the offspring of “mother-stones” or “breeding-stones.” Today, it is known that this motion of stones moving upwards toward the surface of the ground is due to frost heave. Frost heave occurs when water in soil or rock freezes and thaws in a cyclic process. This causes an upward movement of the surface of the ground due to the freezing of water underneath. Geologist Stephen Taber from the University of South Carolina proved through extensive research that “it was not expansion, but rather the formation of ice lenses by segregation of water from the soil as the ground freezes that is the principal cause of frost heave.” He also showed that liquids other than water can also cause frost heave. The direction of heave is governed by the growth of ice lenses. Ice lenses form perpendicular to the direction of heat flow, so it is not always the case that frost heave occurs in the path of least resistance (Manz, 2011). 
      

      References

      Manz, L. (2011). Frost Heave. Geo News, 18-23.

    3. Denison Ice Road
      The Denison Ice Road was constructed by John Denison, an ice road engineer, and his crew. He drove a Caterpillar tractor which pull freight sleighs in harsh environments like those found in Alaska. His experiences with these long drives between mines sparked his interest in designing a road that could support regular transport trucks and vehicles (Princes of Wales Nothern Heritage Center n.d.). The construction of the Denison Ice Road began in the late 1950s. This road was planned to connect Yellowknife through the Arctic Circle to the Great Bear Lake silver mine. This distance totaled about 530 kilometers or 323 miles. John Denison and his crew worked with Byers Transport to complete the construction of Denison Ice Road. Byers Transport was a company that was at the forefront of ice road construction in the North. The construction of the Denison Ice Road was built through some of the most isolated terrain in the sub-arctic region. In 1988, John Denison received the Order of Canada for his successful construction of and ingenuity in building winter roads (Yellowknifer 2001). A detailed account of the experiences of John Denison and his crew during the construction of the Denison Ice Road can be found in “Denison’s Ice Road” by Edith Iglauer. A copy of “Denison’s Ice Road” can be found by following this link: http://www.barnesandnoble.com/w/denisons-ice-road-edith-iglauer/1100112712?ean=9781550170412. 
      

      After completing the Denison Ice Road project, John Denison worked on the construction of a road to Tundra Mine and Discovery Mine. John Denison was married to Hannah with whom he had four kids. His family resided in Edmonton, Alberta and then Kelowna, British Columbia (Yellowknifer 2001).

      References

      Princes of Wales Nothern Heritage Center. n.d. Historical Timeline of the Northwest Territories. Accessed May 7, 2017. http://www.nwttimeline.ca/1950/1959_Denison.htm.

      Yellowknifer. 2001. Articles on John Denison. January 10. Accessed April 9, 2017. http://www.harbourpublishing.com/excerpt/DenisonsIceRoad/webonly/109.