J Ross Mackay
Dados Biográficos
| ID | 3607287 |
|---|---|
| NOME | J Ross Mackay |
| PRENOMES | J Ross |
| SOBRENOME | Mackay |
| ASSINATURA | MACKAY J R |
| VERIFICADO | Não |
| TOTAL DE OBRAS | 25 |
| TOTAL DE CITAÇÕES | 46 |
| TOTAL COMO AUTOR | 25 |
| TOTAL COMO EDITOR | 0 |
| PRIMEIRO ANO DE PUBLICAÇÃO | 1951 |
| ANO MAIS RECENTE DE PUBLICAÇÃO | 1989 |
| ÍNDICE H | 4 |
Ice‐wedge Cracks, Western Arctic Coast
Ice‐wedge ice is one of the most abundant types of nearly pure ground ice to be found along the western Arctic coast and, indeed, in many other permafrost areas of the world. Ice wedges grow because thermal contraction cracks open in winter and become infilled with water in spring to form incremental ice veinlets. Long‐term winter observations along the western Arctic coast have provided details of crack opening and closing, propagation, and crac…
The Birth and Growth of Porsild Pingo, Tuktoyaktuk Peninsula, District of Mackenzie
The birth and growth of Porsild Pingo (ice-cored hill) can be taken as fairly representative of the birth and growth of the more than 2000 closed-system pingos of the western arctic coast of Canada and adjacent Alaska. Porsild Pingo, named after a distinguished arctic botanist, has grown in the bottom of a large lake that drained catastrophically about 1900. Porsild Pingo has grown up at the site of a former shallow residual pond. The "birth" pro…
Growth of Ibyuk Pingo, Western Arctic Coast, Canada, and Some Implications for Environmental Reconstructions
Ibyuk Pingo, which is 49 m high and 300 m in basal diameter, is one of the largest pingos in the world. Precise surveys carried out for the 1973 to 1983 period indicate that the lower half of the pingo, below a height of 25 m, shows no perceptible growth. From 25 m to the top, the growth steadily increases to a maximum of 2.3 cm/yr at the summit. The source of growth is believed to lie at a depth of about 65 m below the highest peak. Evidence bas…
Aklisuktuk (Growing Fast) Pingo, Tuktoyaktuk Peninsula, Northwest Territories, Canada
Field surveys have been carried out for the 1972 to 1979 period in order to study the growth of Aklisuktuk (Growing Fast) Pingo. The field surveys show that the top of the pingo was slowly subsiding during the seven-year survey period, possibly from a slow downslope glacier-like creep of the ice-rich overburden and ice core. The name "Aklisuktuk" probably dates back at least 200 years. The rapid growth which attracted attention was from accumulat…
Snow Cover and Ground Temperatures, Garry Island, N.W.T
Field measurements of the influence of snow on ground temperatures, at a depth of 90 cm., were carried out during 1968-73 at Garry Island, N.W.T. The results show that the ameliorating effect of snow can be expressed by a regression equation. The side slopes tend to have the highest mean annual temperatures; the flats the lowest; and the ridges intermediate. At Garry Island, where permafrost is thick, variations in snow cover are probably not ref…
The World of Underground Ice
Underground ice is restricted to permafrost areas where its distribution is sporadic and often unpredictable. A knowledge of the distribution and abundance of underground ice is essential to northern development, because a variety of man induced disturbances can cause underground ice to thaw, often with serious consequences. The criteria for a classification of the principal types of underground ice are the source of the water prior to freezing a…
The Perception of Conformality of Some Map Projections
r HE visual perception of our environment is so familiar to us that we commonly take it for granted.' However, even an apparently simple phenomenon such as the moon illusion, where the moon appears larger over the horizon than at the zenith, has produced a controversial literature.2 It is not surprising, therefore, that an inquiry into the visual perception of a map projection is beset with difficulties. There must be cartographic and perceptual …
Permafrost Depths, Lower Mackenzie Valley, Northwest Territories
Reports 1965-66 ground temperature records for seven new sites established in the lower Mackenzie valley, indicating permafrost thickness of about 350 ft for Arctic Red River, 400 ft in site 14 mi west of Fort McPherson, 350 ft or more in the south central Mackenzie Delta, and 60-100 ft at four sites in the outer Delta which are within two feet of sea level. In the distal part of the Delta, where new islands are growing, perma- frost is aggrading…
Theoretical Geography
Geomorphologie des Regions Froides
Notes on the Shoreline Recession Along the Coast of the Yukon Territory
The 150-km.-long stretch of the coast between Herschel Island and the Mackenzie Delta terminates in bluffs cut into Pleistocene silts, sands, and gravels. No bedrock has yet been observed; if present, its occurrence must be very local. The coastal bluffs which are up to 50 m. high, are constantly being undermined by waves and by the melting of numerous thick tabular ground-ice sheets lying close to sea-level. As the ice sheets are found only in f…
Isopleth Class Intervals
Conceptually, the isopleths of a map represent the planimetric projection of imaginary isopleths of a statistical surface. As few isopleth maps have more than 10 class intervals, their careful selection is clearly important. If a cartographer can make initial decisions upon the limits of the first class, the lower limit of the last class, and the number of classes, then the intermediate classes are, in a sense, “described.” An equation may theref…
Geomorphology and the Geography Student
Regional geography
The Interactance Hypothesis and Boundaries in Canada
Chi Square as a Tool for Regional Studies
(1958). CHI SQUARE AS A TOOL FOR REGIONAL STUDIES. Annals of the Association of American Geographers: Vol. 48, No. 2, pp. 164-166
"Arctic "Vegetation Arcs
Deformation by Glacier-Ice at Nicholson Peninsula, N.W.T., Canada
Two excellent examples of sediments deformed by glacier ice occur on Nicholson Peninsula, Mackenzie District (Liverpool Bay, 69 54 N, 129 W). Sediments, topography and structure of the Peninsula are described. Altitudes in the hilly northern half attain 200-300 ft. above sea level, whereas those in the south rarely exceed 30 ft. The hills were formed either by glacier ice moved against a topographic obstruction, resulting in a large push moraine,…
Mackenzie Deltas ‐ a Progress Report1
Physical and Biogeography in Canada ‐ (Mid‐1952 to Mid‐1954) 1
An Analysis of Isopleth and Choropleth Class Intervals
(1955). An Analysis of Isopleth and Choropleth Class Intervals. Economic Geography: Vol. 31, No. 1, pp. 71-81
Geographic Cartography 1
Percentage Dot Maps
A LTHOUGH the percentage dot map in which each dot represents a percentage of the distribution is superior to the common dot map for some mapping purposes, it is so seldom utilized that few examples exist in geographic literature.' The purpose of this discussion is to point out several advantages of the percentage dot map and to suggest that this neglected technique might be used more extensively, particularly on economic maps to show distributio…
A New Projection for Cubic Symbols on Economic Maps
A LTHOUGH everyone knows that a sphere cannot be perfectly represented on a plane surface, a surprisingly large number of people tend to forget that the same statement also applies to all solid forms, cubes included. It is no more possible, and no more desirable, to draw a cube without any reference to its projectional properties than it is to do the same with a sphere. The choice of projection involves far more than mere academic interest, becau…
Some Problems and Techniques in Isopleth Mapping
The Interactance Hypothesis and Boundaries in Canada
The World of Underground Ice
Underground ice is restricted to permafrost areas where its distribution is sporadic and often unpredictable. A knowledge of the distribution and abundance of underground ice is essential to northern development, because a variety of man induced disturbances can cause underground ice to thaw, often with serious consequences. The criteria for a classification of the principal types of underground ice are the source of the water prior to freezing a…
Some Problems and Techniques in Isopleth Mapping
An Analysis of Isopleth and Choropleth Class Intervals
(1955). An Analysis of Isopleth and Choropleth Class Intervals. Economic Geography: Vol. 31, No. 1, pp. 71-81
Isopleth Class Intervals
Conceptually, the isopleths of a map represent the planimetric projection of imaginary isopleths of a statistical surface. As few isopleth maps have more than 10 class intervals, their careful selection is clearly important. If a cartographer can make initial decisions upon the limits of the first class, the lower limit of the last class, and the number of classes, then the intermediate classes are, in a sense, “described.” An equation may theref…
Chi Square as a Tool for Regional Studies
(1958). CHI SQUARE AS A TOOL FOR REGIONAL STUDIES. Annals of the Association of American Geographers: Vol. 48, No. 2, pp. 164-166
Mackenzie Deltas ‐ a Progress Report1
Geographic Cartography 1
Ice‐wedge Cracks, Western Arctic Coast
Ice‐wedge ice is one of the most abundant types of nearly pure ground ice to be found along the western Arctic coast and, indeed, in many other permafrost areas of the world. Ice wedges grow because thermal contraction cracks open in winter and become infilled with water in spring to form incremental ice veinlets. Long‐term winter observations along the western Arctic coast have provided details of crack opening and closing, propagation, and crac…
The Perception of Conformality of Some Map Projections
r HE visual perception of our environment is so familiar to us that we commonly take it for granted.' However, even an apparently simple phenomenon such as the moon illusion, where the moon appears larger over the horizon than at the zenith, has produced a controversial literature.2 It is not surprising, therefore, that an inquiry into the visual perception of a map projection is beset with difficulties. There must be cartographic and perceptual …
Theoretical Geography
Geomorphology and the Geography Student
"Arctic "Vegetation Arcs
Physical and Biogeography in Canada ‐ (Mid‐1952 to Mid‐1954) 1
Percentage Dot Maps
A LTHOUGH the percentage dot map in which each dot represents a percentage of the distribution is superior to the common dot map for some mapping purposes, it is so seldom utilized that few examples exist in geographic literature.' The purpose of this discussion is to point out several advantages of the percentage dot map and to suggest that this neglected technique might be used more extensively, particularly on economic maps to show distributio…
A New Projection for Cubic Symbols on Economic Maps
A LTHOUGH everyone knows that a sphere cannot be perfectly represented on a plane surface, a surprisingly large number of people tend to forget that the same statement also applies to all solid forms, cubes included. It is no more possible, and no more desirable, to draw a cube without any reference to its projectional properties than it is to do the same with a sphere. The choice of projection involves far more than mere academic interest, becau…
Some Problems and Techniques in Isopleth Mapping
Percentage Dot Maps
A LTHOUGH the percentage dot map in which each dot represents a percentage of the distribution is superior to the common dot map for some mapping purposes, it is so seldom utilized that few examples exist in geographic literature.' The purpose of this discussion is to point out several advantages of the percentage dot map and to suggest that this neglected technique might be used more extensively, particularly on economic maps to show distributio…
A New Projection for Cubic Symbols on Economic Maps
A LTHOUGH everyone knows that a sphere cannot be perfectly represented on a plane surface, a surprisingly large number of people tend to forget that the same statement also applies to all solid forms, cubes included. It is no more possible, and no more desirable, to draw a cube without any reference to its projectional properties than it is to do the same with a sphere. The choice of projection involves far more than mere academic interest, becau…
Geographic Cartography 1
Physical and Biogeography in Canada ‐ (Mid‐1952 to Mid‐1954) 1
An Analysis of Isopleth and Choropleth Class Intervals
(1955). An Analysis of Isopleth and Choropleth Class Intervals. Economic Geography: Vol. 31, No. 1, pp. 71-81
Deformation by Glacier-Ice at Nicholson Peninsula, N.W.T., Canada
Two excellent examples of sediments deformed by glacier ice occur on Nicholson Peninsula, Mackenzie District (Liverpool Bay, 69 54 N, 129 W). Sediments, topography and structure of the Peninsula are described. Altitudes in the hilly northern half attain 200-300 ft. above sea level, whereas those in the south rarely exceed 30 ft. The hills were formed either by glacier ice moved against a topographic obstruction, resulting in a large push moraine,…
Mackenzie Deltas ‐ a Progress Report1
The Interactance Hypothesis and Boundaries in Canada
Chi Square as a Tool for Regional Studies
(1958). CHI SQUARE AS A TOOL FOR REGIONAL STUDIES. Annals of the Association of American Geographers: Vol. 48, No. 2, pp. 164-166
"Arctic "Vegetation Arcs
Regional geography
Geomorphology and the Geography Student
Notes on the Shoreline Recession Along the Coast of the Yukon Territory
The 150-km.-long stretch of the coast between Herschel Island and the Mackenzie Delta terminates in bluffs cut into Pleistocene silts, sands, and gravels. No bedrock has yet been observed; if present, its occurrence must be very local. The coastal bluffs which are up to 50 m. high, are constantly being undermined by waves and by the melting of numerous thick tabular ground-ice sheets lying close to sea-level. As the ice sheets are found only in f…
Isopleth Class Intervals
Conceptually, the isopleths of a map represent the planimetric projection of imaginary isopleths of a statistical surface. As few isopleth maps have more than 10 class intervals, their careful selection is clearly important. If a cartographer can make initial decisions upon the limits of the first class, the lower limit of the last class, and the number of classes, then the intermediate classes are, in a sense, “described.” An equation may theref…
Theoretical Geography
Geomorphologie des Regions Froides
Permafrost Depths, Lower Mackenzie Valley, Northwest Territories
Reports 1965-66 ground temperature records for seven new sites established in the lower Mackenzie valley, indicating permafrost thickness of about 350 ft for Arctic Red River, 400 ft in site 14 mi west of Fort McPherson, 350 ft or more in the south central Mackenzie Delta, and 60-100 ft at four sites in the outer Delta which are within two feet of sea level. In the distal part of the Delta, where new islands are growing, perma- frost is aggrading…
The Perception of Conformality of Some Map Projections
r HE visual perception of our environment is so familiar to us that we commonly take it for granted.' However, even an apparently simple phenomenon such as the moon illusion, where the moon appears larger over the horizon than at the zenith, has produced a controversial literature.2 It is not surprising, therefore, that an inquiry into the visual perception of a map projection is beset with difficulties. There must be cartographic and perceptual …
The World of Underground Ice
Underground ice is restricted to permafrost areas where its distribution is sporadic and often unpredictable. A knowledge of the distribution and abundance of underground ice is essential to northern development, because a variety of man induced disturbances can cause underground ice to thaw, often with serious consequences. The criteria for a classification of the principal types of underground ice are the source of the water prior to freezing a…
Snow Cover and Ground Temperatures, Garry Island, N.W.T
Field measurements of the influence of snow on ground temperatures, at a depth of 90 cm., were carried out during 1968-73 at Garry Island, N.W.T. The results show that the ameliorating effect of snow can be expressed by a regression equation. The side slopes tend to have the highest mean annual temperatures; the flats the lowest; and the ridges intermediate. At Garry Island, where permafrost is thick, variations in snow cover are probably not ref…
Aklisuktuk (Growing Fast) Pingo, Tuktoyaktuk Peninsula, Northwest Territories, Canada
Field surveys have been carried out for the 1972 to 1979 period in order to study the growth of Aklisuktuk (Growing Fast) Pingo. The field surveys show that the top of the pingo was slowly subsiding during the seven-year survey period, possibly from a slow downslope glacier-like creep of the ice-rich overburden and ice core. The name "Aklisuktuk" probably dates back at least 200 years. The rapid growth which attracted attention was from accumulat…
Growth of Ibyuk Pingo, Western Arctic Coast, Canada, and Some Implications for Environmental Reconstructions
Ibyuk Pingo, which is 49 m high and 300 m in basal diameter, is one of the largest pingos in the world. Precise surveys carried out for the 1973 to 1983 period indicate that the lower half of the pingo, below a height of 25 m, shows no perceptible growth. From 25 m to the top, the growth steadily increases to a maximum of 2.3 cm/yr at the summit. The source of growth is believed to lie at a depth of about 65 m below the highest peak. Evidence bas…
The Birth and Growth of Porsild Pingo, Tuktoyaktuk Peninsula, District of Mackenzie
The birth and growth of Porsild Pingo (ice-cored hill) can be taken as fairly representative of the birth and growth of the more than 2000 closed-system pingos of the western arctic coast of Canada and adjacent Alaska. Porsild Pingo, named after a distinguished arctic botanist, has grown in the bottom of a large lake that drained catastrophically about 1900. Porsild Pingo has grown up at the site of a former shallow residual pond. The "birth" pro…
Ice‐wedge Cracks, Western Arctic Coast
Ice‐wedge ice is one of the most abundant types of nearly pure ground ice to be found along the western Arctic coast and, indeed, in many other permafrost areas of the world. Ice wedges grow because thermal contraction cracks open in winter and become infilled with water in spring to form incremental ice veinlets. Long‐term winter observations along the western Arctic coast have provided details of crack opening and closing, propagation, and crac…
Geography (20 obras) · Geology (11 obras) · Geology (10 obras) · Climate change and permafrost (9 obras) · Physical geography (9 obras) · Computer Science (8 obras) · Geology and Paleoclimatology Research (8 obras) · Oceanography (8 obras) · Oceanography (8 obras) · Cartography (6 obras)