Landscapes in our Environment

what are the four spheres

biosphere, atmosphere, lithosphere, hydrosphere

lithosphere

solid earth. the outer part (crust and the top part of the upper mantle) of the earth

what is the coolest part of the earth

the lithosphere

what does the lithosphere provide

rich source of minerals, supports and provides forests, grasslands, agricultural lands and lands for human settlements

pedosphere

(part of the earth subject to soil forming processes). the uppermost portion of the lithosphere that interacts with the other three spheres

atmosphere

the layer of air that stretches above the lithosphere

stratosphere

calm and stable layer, suitable for flying aircraft, region of ozone formation

troposphere

lowest region of the atmosphere, most of the mass (about 75-80%) of the atmosphere is in the troposphere

• almost all weather occurs within this layer, provides oxygen that we can breath, keeps earth a livable temperature

hydrosphere

refers collectively to all forms of water on earth

• surface water bodies (rivers, oceans, lakes)

• groundwater

• water vapor (clouds, fog)

• ice

biosphere

made up of the parts of earth where life exists. extends from the deepest root system of trees to the dark environment of ocean trenches, to lush rainforests and high mountain tops

landscape

consists of a variety of geographical features that are characteristics of an area

• two categories: natural and human

natural landscapes

creates by forces (processes) that bring changes to the earth’s surface

what two forces create natural landscapes

• endogenic (internal) forces

• exogenic (external) forces

how do endogenic processes begin and what do they cause

form due to the internal heat at the core of the earth. cause vertical and horizontal movement of the earth - known as constructive forces as they help form the earth’s surface

give examples of endogenic processes

earthquakes, volcanic eruptions, mountain formation (orogeny), landslides, seafloor spreading

how do exogenic processes begin and what do they cause

form due to forces that arise within the atmosphere of the earth. considered as destructive forces as they are likely to destroy the existing landform. involve processes that wear away the earth’s surface

give examples of exogenic processes

weathering, erosion, deposition, tornadoes, droughts, rainfall, snowfall, winds, thunderstorms, hailstorms, glaciers, moon tidal force

what is the laurentide ice sheet

4km thick ice sheet formed 2.6 million years ago that covered most of canada. glacier started moving as it got heavy with cycles of advancements and retreats

how was the glacial lake agassiz made

fed by meltwater from the retreating laurentide ice sheet at the end of the last glacial period. around 13,000 years ago it covered much southeastern mb, northwestern ontario, northern minnesota, eastern north dakota and sask. stayed for about 5000 years

lake agassiz formed which lakes in mb

lake wpg, lake mb, lake winnipegosis

what geological feature did lake agassiz leave behind in the red river valley

a flat basin with clay deposits up to 70m deep

what percentage of the red river valley was wetland after lake agassiz drained

about 60%

why is drainage important in the red river valley

to reduce periodic flooding and make use of the fertile soils for agriculture

what are some ways humans transform natural landscapes

agriculture, drainage, floodways, deforestation, dam building, roads, mines, tunnels and settlements

why is tampering with natural landscapes risky

landscapes are highly dynamic and complex, with many dependent and independent variables - ignorant tampering can lead to undesirable outcomes

what are some anthropogenic impacts that make landscapes more habitable

human modifications that adapt natural landscapes for settlement and use

what are examples of land degradation caused by humans

erosion, desertification, salinity and acid mine drainage

how have human impacts changed hydrologic processes

they have caused flooding, poor water quality, and reduced water quality

besides environmental effects, what cultural impacts can anthropogenic change cause

loss of the landscape’s value and loss of culture