Canadian Shield Introduction
The Canadian shield, also known as the Precambrican Shield or Laurentatian Plateau reaches from Quebec and Ontario to Nunavut. It also slightly goes into Saskatchewan. It is the largest land form region in Canada. It is the oldest part of the North American crustal plate. It covers most of Canada and the U.S.
The Canadian Shield can have long winters lasting from 6 to 8 months with day hours ranging from 8.5 hours in the south and 5.5 hours in the north. In general, the winters range from -18 degrees Celsius to -20 degrees Celsius. Summer days can be as long as 18.5 hours in the south and 15 hours in the north. Precipitation is 755 mm to 1015 mm.
The Canadian Shield also holds the oldest rocks in the world, which are 3.96 billion years old. They can be found east of Great Bear Lake. Most of the water in this area drains to the Hudson Bay, James Bay, and Atlantic ocean. The eastern side of the landscape is rugged and hilly with many different sized lakes. The Shield also contains fossils of bacteria and algae over 2 billion years old. The shield's plateau from 305 to 610 meters above sea level.
Vegetation and Soil Type.
There is a small amount of permafrost in the soil. But, around the lowland areas near Hudson's Bay, the grass is soggy. Also around the lowlands is dense soil that is not suitable for forestation. The rest of the region has coarse soil that does not keep the moisture. There are a lot of trees in the landscape ( White and Black Spruce, Jack Pine, Balsam, Fir, and Tamarack). There are also many deciduous trees (Ash, Alter, Birch, Poplar). There is thin soil lying on top of the bed rock which was created by serious glaciation during ice age.
The landscape contains mineral rich metamorphic rock. On the western side of the region, it is underlain by a sedimentary bed rock. The area is also composed of granite. The Shield also has Precambrian rocks that are more than 570 million years old. Igneous rocks in this landscape contains copper, zinc, gold,iron, ore, nickel and uranium.
The Shield is one of the world's wealthiest areas in term of mineral ores.It is filled with substantial deposits of of nickel, gold, silver, and copper. There are many mining towns extracting these minerals. Northeastern Quebec is site of an extensive hydroelectric project which is known as one of the largest known meteorite impacts craters on Earth.
5 popular recreational activities are boating , dogsled riding, fishing, hunting, and cross country
Climate Changes in The Canadian Shield
The increasingly dry northern boreal forest that streches across the Canadian Shield have seen burns ascending from 1 million hectares (10 000 000 000 m^2) to 3 million hectares (30 000 000 000 m^2) in the last 10 years. Also, the cool and cold freshwater fish population (trout, white fish, and grayling) could be reduced in multiple lakes and streams on the Shield due to descending water levels and flow and reductions in nutrient load and recycling.
Risks of Natural Disasters
Each year, around 450 earth quakes happen near the Canadian Shield. Although there are around 450 earthquakes, only it may be only 4 that will exceed a magnitude of 4 and 30 will exceed a magnitude of 3 which is some what strong enough to be felt right away. The reasons for the many earthquakes are not well understood but the earthquake activity in the area seem to be associated to the regional stress fields, with the earthquakes focused in regions of crustal weakness.
Safety for Earthquakes
If the event of a major earthquake happens while you are in the Canadian Shield, you must take precautions. To reduce the chances of injury drop down onto your hands and knees. This stance allows you to prevent you from falling but still gives you the mobility to move if needed. Also, it is important to cover your head and neck. This is only to be used if there is no shelter near by. If you do fins shelter, hold on to your shelter until the shaking stops. Also be ready to move shelters if the shaking shifts it around.