For the Love of Geography: Pyramidal peak

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Grand Teton

A pyramidal peak or glacial horn is a sharply pointed mountain peak usually with three sides. When three or more glacial cirques erode backwards to a central point they form a triangular peak, a pyramidal peak or horn.

 

Glacier National Park

Glacier National Park

The number of faces on a horn depends on how many cirques come together, however the most common is three or four. When a peak has four symmetrical sides it’s called a matter horn after the Matterhorn peak in the Alps.

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Teton Range

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For the Love of Geography: Glacial Erratics

A glacial Erratic is a large boulder that was transported by glacier to an area of different rock in type and size. These erratics can be transported hundreds of miles.

Plymouth Rock, Plymouth MA & Lassen Volcanic National Park, CA

For the Love of Geography: U-Shape Valley

U-Shaped valleys are just what they sound like – a valley shaped like a “U”. These valleys are the result of glaciers carving further into an existing depression created from a river called a v-shaped valley. The valley is transformed from gradually sloping side to steep sides and a flat bottom. Rivers often remain from glacial melting that replace the original river. U-shaped valleys are found at high mountain altitudes worldwide.

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Rocky Mountain National Park, Colorado

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Gifford Pinchot National Forest, Washington

For the Love of Geography: Moraine

Moraine is a glacial landforms which results from glacial movement. As a glacier moves down the mountain it leaves behind debris of dirt and boulders.

Look below the glaciers in these photos. It looks like a river of rock. This is the debris left from the glaciers above which have retreated for the summer months.

Grand Teton National Park

For the Love of Geography: Arêtes

We continue our study on mountain glacial landforms with the arête.

An arête is formed by two glaciers scouring away rock on two sides of a mountain. The result is a thin ridge of rock which separates two U-Shaped valleys. Weathering further erodes the rock thus shaping and sharpening the feature. Arêtes can also be formed when two cirques erode.

For the Love of Geography: Tarn (glacial lake)

A TARN is a lake created in a cirque by glacial melt water, rain,  river runoff or a combination.

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Lake Jenny, Lassen National Volcanic Park, California

For the Love of Geography – Cirque

A cirque is a semicircular shaped bedrock feature high on mountainside partially surrounded on three sides by steep cliffs. Cirques are created by the advancing and retreating of glaciers. The basin becomes deeper and wider in diameter each year as it continues to be eroded. An interesting feature of a cirque is the tarn or glacial lake which results from melting glaciers.

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Cirque, Grand Teton, Wyoming

Sometimes multiple cirques will form, the rock in between is an arête, a steep ridge dividing the two cirques. When three cirques form the result is a glacial horn (or pyramidal peak) such as the Matterhorn in the Alps or Irene’s Arête in the Tetons.

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Cirques and arêtes, Mount Moran, Wyoming

Photos taken at Grand Teton National Park

For the Love of Geography: Fresh water ecosystems

Fresh water ecosystems are not forests but contain various forms of plants, shrubs and trees that thrive in a watery home.  Included in these ecosystems are marshlands, swamps, wetlands.

Tidal Salt Marsh: Grays Beach, Yarmouth Port, Massachusetts

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Forested Swamp: Cypress Swamp, Natchez Trace Parkway, Mississippi

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Fen: Mounds State Park, Indiana

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Freshwater Marsh: Everglades National Park, Florida

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For the Love of Geography: Hot Dry Forests

Dry, warm forests include savannah, chaparral and desert. Dry forests have a combination of grasslands, shrubs and small trees.

  • Savannah is a warm dry forest characterized by grasses, palm, pine, and acacia. 

Big Cypress National Preserve

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  • Chaparral forests (Mediterranean) have significant numbers of trees but with grassland mixed in. It is often referred to as scrub. 

Crystal Grove State Park, California

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  • Deserts receive so little rainfall that only xerophytic (water retaining) plants. These plants and trees include the dragon tree, Joshua tree, aloe and yucca.          

Coronado National Forest, Arizona

Other posts in this series on Forests: Temperate Forests, Coniferous Forests, Deciduous Forests, Cold Dry Forests, Hot Dry Forests 

For the Love of Geography: Cold Dry Forests

People often imagine a dry forest as a hot environment; however, cold climates can also be dry. Dry, cold forests include steppe and alpine. Dry forests have a combination of grasslands, shrubs with groupings of various types of trees including conifers.

  • Steppe is a cold dry forest close to montane barriers. Halfway between a forest and desert it consists of grasslands, shrubs and sparse groupings of trees

Caribou National Forest, Idaho

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Fossil Butte National Monument, Wyoming

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  • Alpine forests, often referred to as montane forests, occur above 10,000 feet and have long winters. Plants are small and close to the ground. Conifers are sparse.   

Mt Shastina, California

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Other posts in this series on Forests: Temperate Forests, Coniferous Forests, Deciduous Forests, Cold Dry Forests, Hot Dry Forests