Browse "Nature & Geography"

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Thrasher

Thrashers (Mimidae) are a small family of slender, long-tailed, medium-sized, insectivorous and frugivorous birds with loud, musical, repetitive songs.

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Thrips

Thrips, order Thysanoptera (Gk for "fringe-wings"), are among the smallest insects, being slender and usually less than 2 mm long.

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Thrush

Thrushes (Muscicapidae) are a very large family comprising about 450 species of small passerines (perching birds) ranging 11-33 cm in length.

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Thunderstorm

Thunderstorms usually occur on summer afternoons. While a thunderstorm typically affects a given locality for only an hour or so during its passage overhead, the entire lifetime may be as long as 6-10 hours, along a pathway of several hundred kilometres.

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Tick

Tick is a common name for a group of external bloodsucking parasitic arthropods of vertebrates (mainly of terrestrial mammals and birds).

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Tidal Energy

Tidal energy is a largely untapped, renewable energy source based largely on lunar gravitation. While the potential of tidal hydroelectricity has long been recognized, compared to river dams, tidal power projects are expensive because massive structures must be built in difficult saltwater environments.

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Tide

The Earth is actually not in orbit around the sun but around the centre of mass of the Earth-sun system. Since all parts of the Earth move in the same orbit, they experience the same acceleration, but only at the Earth's centre is this acceleration exactly balanced by the sun's gravitation.

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Timber Slide

A timber slide is a water-filled chute or runway built to carry rafts of timber around rapids and falls.

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Titanium

Titanium (Ti) is a metallic element estimated to form about 0.5% of the rocks of the Canadian SHIELD. Titanium minerals of commercial importance include the dioxides rutile and anatase, which are polymorphs of TiO2 and ilmenite (FeO.TiO2), a mineral that contains 52.7% TiO2.

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Toad

Toad is a common name for certain members of the amphibian order Anura, the frogs.

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Tobacco

Tobacco (Nicotiana tabacum) is an annual (potentially perennial) herbaceous plant of the nightshade family.

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Tobacco-Products Industry

Although Canada's tobacco industry has developed largely during this century, tobacco growing goes back to early colonial days, when settlers around the St Lawrence River adopted the smoking customs of aboriginal peoples. French settlers began by copying the agricultural model set by the Indians.

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Tomato

Tomato (Lycopersicon esculentum) is a herbaceous perennial which, in Canada, is grown as an annual because of early frost.

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Tornado

Tornadoes are a type of severe storm. They are typified by a funnel-shaped cloud descending toward the earth.

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Toronto Feature: Hurricane Hazel

Hurricane Hazel was one of the most devastating and unpredictable tropical storms of the 20th century. It was first identified on 5 October 1954, in the Caribbean, where it smashed into Haiti and then battered the Carolinas. The storm struck Toronto on 15 October with winds of 124 km/h and record rainfall.

Macleans

Toronto's Record Snowstorm

As a storm raged outside, the constantly ringing phones went unanswered at Environment Canada’s Toronto offices last Thursday. Like many other workplaces in the city, it was shut down - by the worst series of blizzards ever to strike Toronto.

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Touch-me-not

Touch-me-not, or Jewelweed, are common names for family of herbaceous plants (Balsaminaceae) of which Impatiens is the principal genus. The genus name derives from the fact that a ripe seed capsule, when touched, explodes violently, projecting seed some distance.

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Treeline

The treeline is controlled by CLIMATE in interaction with SOIL. In the North, it is correlated generally with the modal (most common) position of the southern edge of the arctic front in summer, and with such temperature indices as the July 10°C isotherm.

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Trees

Trees are single-stemmed, perennial, woody plants taller than 3 m and exceeding 8 cm in diameter at breast height; shrubs are multistemmed and smaller. These definitions are somewhat arbitrary, since many species (eg, willow, alder, cherry, maple) can grow as trees or shrubs, depending on the environment. Counting the 30-odd shrubs that assume tree form under favourable conditions, there are about 140 native Canadian trees.

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Trillium

Trillium, common and generic name of a perennial plant of the Trilliaceae family (sometimes classified as a subfamily of the LILY family). The name derives from the arrangement of leaves, petals and sepals in groups of 3. The