Table of Contents
Laurentian Climate or Cool Temperate Eastern Marine Climate
- Intermediate type of climate between the British Type Climate (moderate) and the Taiga Type Climate (extreme) of climate.
- It has features of both the maritime and the continental climates.
Distribution of Laurentian Climate
- Laurentian type of climate is found only in two regions and that too only in the northern hemisphere.
North American region
- North-eastern North America, including eastern Canada, north-east U.S.A., and Newfoundland. This may be referred to as the North American region.
- Eastern coastlands of Asia, including eastern Siberia, North China, Manchuria, Korea and northern Japan.
Absent in Southern Hemisphere
- In the southern hemisphere only a small section of continents extends south of 40°S latitude.
- Some of these small sections come under the rain-shadow region of Andes (Patagonia) and hence Westerlies hardly ever reach these regions.
- So these regions are subjected to aridity rather than continentiality.
- In other regions, the oceanic influence is so profound that neither the continental nor the eastern margin type of climate exists.
- Characterized by cold, dry winters and warm, wet summers.
- Winter temperatures is below freezing-point and snow fall is quite natural.
- Summers are as warm as the tropics (~25 °C).
- Rainfall occurs throughout the year with summer maxima [easterly winds from the oceans bring rains]
- Annual rainfall ranges from 75 to 150 cm [two – thirds of rainfall occurs in the summer].
- Dry Westerlies that blow from continental interiors dominate winters.
The North American region
- In summer, prolonged heat waves cause discomfort.
- In winter, the temperature drops below freezing and snowfall occurs.
- Precipitation occurs all-round the year due to the influence of Atlantic ocean (summer) and the Great Lakes (winter).
- The warm Gulf Stream increases the moisture of easterly winds.
- The prevailing Westerlies carry depressions over the Great Lakes towards eastern regions causing wet conditions in winter [vital for the agricultural activities].
- Convergence of the warm Gulf Stream and the cold Labrador Current near Newfoundland produces dense mist and fog and gives rise to much precipitation.
- It is said that Newfoundland experiences more drizzles than any other part of the world.
The Asiatic region
- Rainfall distribution of the Asiatic region is far less uniform when compared to North American Region.
- Winters are cold and very dry while summers are very warm and exceptionally wet.
- The rainfall regime resembles the tropical monsoon type in India.
- Intense heating of the mountainous interior of China in summer creates a region of extreme low pressure, and moisture-laden winds from the Pacific Ocean and the Sea of Japan blow in as the South-East Monsoon.
- Thus the Laurentian type of climate in China is often described as the Cool Temperate Monsoon Climate.
- It has a very long, cold winter, and a large annual range of temperature.
- Much of the winter precipitation in northern China, Korea and Hokkaido, Japan, is in the form of snow.
- The climate of Japan is modified by the meeting of warm and cold ocean currents.
- It receives adequate rainfall from both the South-East Monsoon in summer and the North- West Monsoon in winter (western coasts of Japan)
- The warm Kuroshio makes the climate of Japan less extreme.
- The meeting zone between warm Kuroshio from south and cold Oyashio from the north produce fog and mist, making north Japan a ‘second Newfoundland’.
- Fishing replaces agriculture as the main occupation in many of the indented coastlands.
Climate Graph for Laurentian Climate
Natural Vegetation – Laurentian Climate
- The predominant vegetation is cool temperate forest.
- The heavy rainfall, the warm summers and the damp air from fogs, all favor the growth of trees.
- Forest tend to be coniferous north of the 50°N latitude.
- In the Asiatic region (eastern Siberia and Korea), the coniferous forests are a continuation of the great coniferous belt of the taiga.
- Timber and fish are the leading export items.
- Much of the coniferous forests of fir, spruce and larch are exploited to a great extent.
- Eastern Canada is the heart of the Canadian timber and wood pulp industry [St. Lawrence River helps in export].
- South of latitude 50°N., the coniferous forests give way to deciduous forests. Oak, beech, maple and birch are most common.
- Almost homogeneous species of trees [pure stands], and the predominance of only a handful of species greatly enhance the commercial value of these forests.
- They have been extensively felled for the extraction of temperate hardwood. [From Laurentian Climate regions, both temperate hardwood and temperate softwood are obtained]
- In Manchuria, Korea and Japan, the forests have made way for the agriculture.
Economic Development – Laurentian Climate
- Lumbering and its associated timber, paper and pulp industries are the most important economic undertaking.
- Agriculture is less important because of long and severe winters.
- In the North American region, farmers are engaged in dairy farming.
- The Annapolis valley in Nova Scotia is the world’s most renowned region for apples.
- Fishing is, however, the most outstanding economic activity.
Fishing off Newfoundland
- Regions around the Grand Banks of Newfoundland are the world’s largest fishing grounds.
- Mixing of warm Gulf Stream and cold Labrador currents make the region the most productive fishing ground on earth.
Fish feed on minute marine organisms called plankton. Plankton is abundantly available in shallow waters [continental shelves] where they have access to both sunlight as well as nutrients. Also, cold and warm water mixing creates upwelling of cold nutrient rich water to the surface.
- The gently sloping continental shelves stretch for over 200 miles south-east of Newfoundland, and off the coasts of the Maritime Provinces and New England.
- Hence microscopic plankton are abundant [Continental Shelf + Mixing of Warm and Cold Ocean Currents].
- Fish of all types and sizes feed and breed here and support a thriving fishing industry.
- Along with Canada and U.S.A., countries like Norway, France, Britain, Portugal, Denmark, Russia and Japan, also send fishing fleets to the Grand Banks.
- In Newfoundland, fishing provides employment for almost the entire population.
- Further inland, in lakes and rivers, such as the St. Lawrence and the Great Lakes, freshwater fish, e.g. salmon etc. are caught.
- All the fishing activities are carried out by highly mechanized trawlers which can store fish in refrigerated chambers for months.
- St. John’s, chief port of Newfoundland is the headquarters of the Grand Banks fishing industries.
- All processing activities like cutting, cleaning, packing for disposal are done at the ports itself.
- Over-fishing is a growing problem.
Fishing off Japan
- North-west Pacific surrounding the islands of Japan is another very important fishing grounds of the world.
- Majority of the people in the region depend on fishing for survival.
- Hakodate and Kushiro are large fishing ports with complete refrigeration facilities.
- The Japanese fishing trawlers venture far and wide into the Arctic, Antarctic and the Atlantic waters.
- Large whaling fleets with processing plants venture into distant regions as far as Arctic and Antarctic [Japan is criticized for its whaling operations].
- Japan accounts for a sixth of the world’s total annual fish caught.
- The Japanese make use of fish wastes, fish meal and seaweeds as fertilizers in their farms.
- Japan is one of the few countries that has taken to seaweed cultivation (India is taking baby steps in seaweed cultivation).
- Coastal farms that are submerged in water grow weeds for sale as fertilizers, chemical ingredient and food.
- Another aspect of Japanese fishing is pearl culture. Pearls are harvested from pearl oysters.
- As natural pearls are difficult to obtain in large numbers, so the Japanese have begun to harvest ‘cultured pearls’.
Why is fishing the dominant occupation of Japan?
- The mountainous nature of Japan and parts of mainland eastern Asia support little agricultural activity [80 per cent land in Japan is classed as ‘non-agricultural’. Around 50% of the total land is covered by forests].
- Japan is not well endowed with natural resources. So, she has to take to the sea if she wants to survive.
- The scarcity of meat (there is little pasture in Japan for livestock farming of any kind) popularized fish as the principal item of diet and the chief protein food of the Japanese and the Chinese as well.
- There exists a great demand for fish and fish products in the nearby countries where fishing industry in under-developed.
- Japan has huge stakes in international fishing enterprises and her advanced fishing techniques give her an edge over competitors.
- Advanced financial services, encouraging government policy, advanced technology at hand, skilled workforce with decades of experience in fishing and the only available natural resource to exploit, make Japan a leader in fishing industry.
- The continental shelves around the islands of Japan are rich in plankton, due to the meeting of the warm Kuroshio and the cold Oyashio currents and provide excellent breeding grounds for all kinds of fish.
- The indented coastline of Japan, provides sheltered fishing ports, calm waters and safe landing places, ideal for the fishing industry.
Compare and contrast the climate of the following pairs of areas.
- Laurentian Climate in the North American region and the Asiatic region.
- Tropical monsoon Climate of India and the Warm Temperate Eastern Margin (China type) Climate in S. China.
- The Steppe type of climate in Eurasia and the Siberian type (Taiga climate) of climate in northern Canada.
- The Tundra Climate of Greenland and Trade Wind Desert Climate of central Australia.
Name the major fishing areas of the world. Explain the geographical factors which have contributed to its importance.
Write brief notes on
- The economy of the forests of the Laurentian regions.
- Fishing in Japan.