Geography - Unit 5

ORM

aka: Oak Ridges Moraine

When did the ORM form?

• at the end of the last ice age

• approximately 12 000 yrs ago

How was the ORM formed?

• it formed along the edges of a glacier as it retreated depositing till between two lobes or fingers of ice

What is till?

• sand and gravel

Headwaters

• where a stream or river starts

The ORM is the headwaters to how many streams and rivers?

• approximately 30 rivers and streams

Name 2 rivers that have headwaters in the ORM found in the city of Toronto?

• The Humber River

• The Don River

What is an aquifer?

• a layer of sand, silt and gravel that holds groundwater

Why are aquifers important?

• they hold groundwater

• they connect with rivers and streams

• they supply (well) water for homes and farms on the ORM

Where can we find the ORM?

• it is found North of the city and stretches about 160 km across the top of the GTA

• Southern Ontario between Lake Ontario, Georgian Bay (Lake Huron), and Lake Simcoe

How big is the ORM?

• 160 km long

• 1 to 15 km wide

• some areas rise to approximately 300 m

• in some areas, the deposits of sand and gravel are up to 200 m thick

How much of the ORM is in the GTA?

• approximately 65% of the ORM is in the GTA

What impact does the ORM have and why is it important?

• the ORM influences the flow of both surface water and groundwater

• the ORM also affects climate in the GTA

What are kettle lakes on the ORM?

• depressions filled with water

What are kettles on the ORM?

• when kettle lakes dry up they are known as kettles

How are kettle lakes formed?

• they are formed when a piece of ice sheet broke off and then later melted, leaving a "kettle" or hole

Where does the water that falls on the moraine go?

• it trickles down through the till to the aquifer

• it runs into a river that flows into Lake Ontario

• it runs into a river that flows into Lake Simcoe or Lake Huron (Georgian Bay)

Why is the ORM known as the RAIN BARREL for the GTA?

• when rain/snow falls on the ORM, it percolates into the ground and replenishes the supply of groundwater

• the kettles trap surface water which then seeps slowly into the ground

• once it reaches a less permeable layer, it moves sideways and emerges as wetlands or springs

• these springs make up approximately 60% of the headwaters in the GTA

How does the ORM impact water?

• natural filter for groundwater and rivers

• provides wetlands which are important habitats for flora and fauna

• plants in wetlands also filter pollutants

• resupplies the groundwater

What is flora and fauna?

Flora is plant life; fauna refers to animals

What are some issues with agriculture on the ORM?

• important for dairy and orchard farming

• close to majority of Ontario's population for supply and quality

• loss of farmland could mean more expensive food

• land on the ORM is valuable and struggling farmers could sell their land and make a lot of money

How does urbanization impact the ORM?

• population growth in GTA is creating a demand for housing

• developers want to build on ORM because of how close it is to Toronto and the scenic views

• building and construction on the ORM can impact water QUALITY AND QUANTITY

How can construction impact the ORM?

• the infrastructure needed to support new developments will also take away land from the ORM

• it will disrupt water flow and pollute both surface and groundwater

What is the Greenbelt?

A ring of land maintained as parks, agriculture, or other types of open space to limit the sprawl of an urban area.

What is urban sprawl?

• the uncontrolled expansion of urban areas into rural areas

What is Aggregate?

• Mixture of sand & gravel

What is surface water?

• water that is on or above the surface of the land

What is groundwater?

• water that flows below the surface into the cracks and spaces in the soil and rock layers

What is carrying capacity?

• the number of people, other living organisms, or crops that a region can support without environmental degradation.

What is habitat?

• the natural home or environment of an animal, plant, or other organism.

What is urban renewal?

the redevelopment of poor areas within a large city

What 2 major landforms are found in the Greenbelt?

• The Niagara Escarpment

• The ORM (Oak Ridges Moraine)

What is a wetland?

-A land area that is covered with a shallow layer of water during some or all of the year

• consisting of swamps, marshes, saturated land

• can be a transitional biome between an aquatic (water) ecosystem and a terrestrial (land) ecosystem

What is sustainability?

• development that ensures that future generations will have equal access to the resources that our planet offers