Category Ecology

Glaciers are keystones of Life on Earth. As giant freshwater reservoirs, they support the planet’s life systems and influence our day-to-day lives, even for communities who live far away from them. However, glaciers are disappearing.

The disappearance of glaciers makes visible the invisible. It makes tangible the current climate change that can be hard to perceive in other ecosystems. The recent evolution of glaciers found in World Heritage sites paints a true picture of their decline in a warming planet.

A study led by Jean-Baptiste Bosson in 2019 shows that most World Heritage glaciers have lost a significant portion of their mass since 1900; some even completely disappeared, as in Africa or the Alps. The study predicts that glaciers could disappear from almost half of World Heritage sites by 2100 if business-as-usual emissions continue.

Credit: International Union for Conservation of Nature

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Glaciology is the study of natural forms of ice, particularly glaciers, and phenomena related to ice. It includes the study of how glaciers are formed and depleted, how they move, and how they affect the physical landscape, the climate, and living organisms. It is one of the key areas of polar research. It also involves research into glacial history and the reconstruction of past glaciation, thus providing insights into the ice ages. The apparent presence of ice on Mars and Jupiter’s moon Europa brings in an extraterrestrial component to the field.

Thus, glaciology is an interdisciplinary earth science, integrating geophysics, geology, physical geography, geomorphology, climatology, meteorology, hydrology, biology, and ecology. The impact of glaciers on humans adds the fields of human geography and anthropology. A person who studies glaciers is called a glaciologist.

Credit: New World Encyclopedia

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Glacial ice is a different color from regular ice. It is so blue because the dense ice of the glacier absorbs every other color of the spectrum except blue — so blue is what we see!

It’s Not Just Frozen Water!

Sometimes the glacial ice appears almost turquoise. Its crystalline structure strongly scatters blue light. The ice on a glacier has been there for a really long time and has been compacted down so that its structure is pretty different from the ice you normally see. Glacial ice is a lot different from the frozen water you get out of the freezer.

It’s Not Just Frozen Snow!

Glacial ice is not just frozen compacted snow. There are other things in the ice that make it much different from the ice in your home. Glaciers move through rock and soil as they carve their way down a slope. This means the ice is going to have a lot more ingredients than just water.

Credit: Alaska Satellite Facility

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Crevasse, fissure or crack in a glacier resulting from stress produced by movement. Crevasses range up to 20 m (65 feet) wide, 45 m (148 feet) deep, and several hundred metres long. Most are named according to their positions with respect to the long axis of the glacier. Thus, there are longitudinal crevasses, which develop in areas of compressive stress; transverse crevasses, which develop in areas of tensile stress and are generally curved downstream; marginal crevasses, which develop when the central area of the glacier moves considerably faster than the outer edges; and bergschrund crevasses, which form between the cirque and glacier head. At the terminus of the glacier many crevasses may intersect each other, forming jagged pinnacles of ice called seracs. Crevasses may be bridged by snow and become hidden, and they may close up when the glacier moves over an area with less gradient.

Credit: Britannica

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Glaciers are huge masses of ice that cover the basement rock. They are found only in regions where snow cover is permanent, that is, at the poles and at high altitude.

At low temperatures, snow does not melt. It accumulates and is compacted into ice. This gradual metamorphosis, which can take several decades, results in the formation of an enormous mass of ice, several dozen meters thick–a glacier.

Propelled by its own weight, a mountain glacier may become detached from the rock wall and slide downward. It slowly flows into the valley like a river of ice. As it descends, the glacier picks up rocks and debris, which accumulate in the form of mounds, called moraines.

If the climate warms, the glacier melts. We say that it recedes. It leaves behind a profoundly eroded landscape composed of wide, flat bottom valleys and many lakes.

Credit: Britannica

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The world’s largest glacier is the Lambert glacier in Antarctica, according to the United States Geological Survey. The glacier is more than 60 miles (96 km) wide at its widest point, about 270 miles (435) long, and has been measured to be 8,200 feet (2,500 meters) deep at its center.

Glaciers form when the annual snowfall in a region exceeds the rate at which the snow melts, allowing enormous amounts of snow to accumulate over time. The fallen snow compresses into solid ice under its own weight, forming solid sheets of ice.

And these sheets are in motion. Glaciers flow like very slow-moving rivers, and can stretch over hundreds of miles. The Lambert glacier flows at a rate of about 1,300 to 2,600 feet (400 to 800 meters) each year.

Credit: LIVE SCIENCE

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