Geology Earth Science Glaciers

Till refers to poorly sorted glacial material, which is a mixture of different sizes and types of sediment deposited by glaciers. It is typically unsorted and contains a range of particle sizes, from large boulders to fine silt. Till is formed when glaciers transport and deposit sediment, and it is often found in areas that were once covered by glaciers. This answer accurately describes the nature of poorly sorted glacial material.

Moraines are accumulations of rock debris (till) carried and deposited by glaciers. They come in various forms, such as lateral moraines (formed along the sides of a glacier), medial moraines (formed when two glaciers merge), and terminal moraines (formed at the furthest extent of a glacier's advance). The other options are erosional features: cirques are bowl-shaped depressions, arêtes are sharp ridges, and horns are pointed peaks carved by glacial action.

A large mass of ice that accumulates over 100s-1000s of years is called a glacier.

Valley and ice sheets are two types of glaciers. Valley glaciers are long, narrow glaciers that form in mountain valleys and flow down through them. They are typically found in high-altitude regions. Ice sheets, on the other hand, are large, continental-scale glaciers that cover vast areas of land. They are found in polar regions, such as Antarctica and Greenland. Both valley and ice sheets glaciers play a significant role in shaping the landscape and contributing to sea-level rise when they melt.

A horn refers to a pyramid-like peak formed by the erosion of multiple glaciers on three or more sides. This process creates steep and sharp mountain peaks with ridges extending from each side. These distinctive features are commonly found in glaciated mountain ranges and are a result of the powerful and continuous erosive forces of glaciers.

A cirque refers to a bowl-shaped depression that forms at the head of a glacial valley. These depressions are typically surrounded by steep walls and are created by the erosive action of glaciers. As the glaciers move downslope, they carve out these hollows through the process of plucking and abrasion. Over time, these cirques can accumulate snow and ice, forming glacial lakes or tarns. The distinctive shape of cirques makes them easily identifiable features in mountainous regions that have been shaped by glacial activity.

Aretes are knife-like ridges. They are narrow, sharp-edged ridges that are formed when two glaciers erode parallel valleys on either side, leaving a sharp ridge between them. These ridges often have steep, vertical sides and can be quite narrow. The term "knife-like" is used to describe their sharpness and resemblance to a knife blade.

A U shaped glacial trough refers to the process in which valley glaciers widen, deepen, and straighten stream valleys. This occurs when glaciers move through a valley, eroding the sides and bottom of the valley and reshaping it into a U-shaped cross-section. The glacier's immense weight and movement cause it to scrape and pluck rocks, carrying them along and further deepening and widening the valley. As the glacier retreats, it leaves behind a U-shaped valley with steep sides and a flat bottom, contrasting with the V-shaped valleys formed by rivers.

Ice sheets are only found in Antarctica and Greenland because these regions have the necessary conditions for the formation and maintenance of large ice sheets. Antarctica is the coldest continent on Earth and contains the South Pole, which experiences extremely low temperatures and receives high amounts of snowfall. Greenland, on the other hand, is located in the Arctic region and also has a cold climate with significant snowfall. These factors allow for the accumulation of snow and ice over time, resulting in the formation of thick ice sheets. Other continents, such as Australia, do not have the same climatic conditions to support the development of ice sheets.

A fiord is a drowned glacial valley along a coast. This means that it is a valley that was formed by a glacier during the ice age and later flooded by rising sea levels. The result is a deep, narrow inlet of water with steep sides, often surrounded by high cliffs or mountains. Fiords are typically found in areas with a cold climate and were carved out by the movement of glaciers over thousands of years. They are known for their stunning natural beauty and are often popular tourist destinations.

Valley glaciers are found on all continents except Australia. This is because valley glaciers require specific conditions to form, such as high elevations and cold temperatures. These conditions are found in various regions around the world, including North America, Europe, Asia, and South America, which is why valley glaciers can be found on all continents except Australia. The absence of valley glaciers in Australia can be attributed to its relatively low elevation and warm climate, which are not conducive to the formation and maintenance of glaciers.

Drumlins are asymmetrical hills composed of till, which is a mixture of clay, sand, and gravel deposited by glaciers. These hills are typically elongated and have a smooth, rounded shape, with one end being steeper and more tapered than the other. They are formed when glaciers move over the landscape, picking up and depositing material as they go. The asymmetrical shape of drumlins is a result of the glacier's movement, with the steeper side facing the direction from which the glacier came.

A depression formed when a block of ice is left behind by a retreating glacier and buried in drift is called a kettle. As the glacier melts, the block of ice is left behind and becomes buried in sediment. Over time, the ice block melts completely, leaving a depression in the landscape. These depressions are often filled with water, forming kettle lakes. Kettles are commonly found in areas that were once covered by glaciers, such as parts of North America and Scandinavia.

Ice sheets often produce rolling topography due to the movement of the ice. As the ice sheet flows, it can create undulating or rolling landforms on the surface. This is caused by the differential movement of the ice, with areas of faster flow creating ridges or hills, while areas of slower flow create depressions or valleys. The weight and pressure of the ice can also cause the underlying land to deform, further contributing to the rolling topography. This type of landscape is commonly found in regions where large ice sheets or glaciers have covered the land, such as in parts of Antarctica or Greenland.

Meltwater flowing from glaciers carries a large load of sediment, which causes the formation of braided streams. These streams have multiple interconnected channels that constantly split and rejoin, creating a braided appearance. The high sediment load in the meltwater causes frequent deposition and erosion, resulting in the formation of numerous small channels. Braided streams are commonly found in glacial environments where the melting ice produces significant amounts of sediment that is transported by the flowing water.