All About Water

The health of our ocean is critical to the health of our planet. Our planet depends upon the ecological processes of a healthy ocean and the resources that the ocean provides us. Unfortunately, for much of history our perception of the ocean’s seemingly infinite vastness and abundance has led us to mistakenly believe that our actions will not significantly impact the oceans. While the ocean is vast and abundant, human impact nevertheless threatens ocean biodiversity. Most governments do not adequately protect marine environments. We have focused our conservation efforts on coastal and near-shore areas, but the open ocean still remains vulnerable to pollution. Some areas of the ocean, such as the open ocean and the deep sea, are not regulated by any government agency. Because of the excessive pollution of marine waters, ocean biodiversity is in great danger.

Ocean biodiversity is the variety of marine organisms present in the ocean and the ecological processes that sustain their lives. The ocean’s biodiversity provides us living resources that are critical to our economic and cultural systems. For instance, according to the National Marine Fisheries Service, sixteen percent of the animal protein that humans consume comes from marine organisms; the fishing industry brings in around $80 billion dollars’ worth of fish each year.

The value of ocean biodiversity transcends economic worth; the oceans perform functions critical to our planet’s ecological health and stability. The ocean stores carbon, regulates atmospheric gas, cycles nutrients, and treats waste treatment. Studies indicate that the living resources of the ocean are severely threatened, but because scientific knowledge of marine organisms and their ecological processes is limited, the consequences of the loss of these living resources cannot be fully understood.

There are many different disturbances to ocean biodiversity, like fisheries, chemical pollution, eutrophication, invasion of exotic species, and plastic debris. Plastic debris comes from many sources, such as from fisheries, ships, and world-wide littering. Often land-litter leaks into rivers that eventually run into the ocean. Fishing operations also threaten the oceans upon which they depend. Fisheries annually destroy sixty billion pounds of by-catch sea life. This destroyed by-catch sometimes includes protected species. Furthermore, fisheries’ equipment often destroys marine organisms’ habitats.

How are they formed?

Glacier ice is formed by the accumulation of snow and ice until the force of gravity deforms the ice and gives it a plasticity that allows it to begin moving, however slowly. Our Earth has been sculpted by glacier ice, and at one time, a third of the surface was covered by ice. In modern times, only ten percent of the surface is covered by ice, but that ice contains up to seventy percent of the world’s fresh water supply.

What is the effect of pollution on the amount of glaciers?

Pollution has little direct affect on most glaciers, but “brown clouds” in Asia may affect glacier ice in the Himalayas.  The clouds are made of particulates, which lower the albedo of the ice, allowing it to absorb more warmth from the sun and leading to increased melting. Not only could this cause flooding downstream, washing pollution into major rivers, but in the long run could reduce drinking water available to some of the most heavily populated areas in the world.

Can we get fresh water from glaciers?

Glacier ice is a leading source of fresh drinking water for much of the world. Water isn’t collected from the glacier itself, but from the flow of melt water from the ice mass. That fresh water is released to flow toward the ocean, and people capture some of it for use in drinking and irrigation.

Do glaciers collect pollution?

Recent studies show that glacier ice may lock organic pollutants within and release it when melting. Lakes that are monitored for the presence of certain substances showed a sharp decrease in pollution due to control of the environment in the 1990s and now are on the increase. Scientists believe that pollutants became trapped into the ice and are now being released.

Does the reduction of glaciers effect any species? How?

Many species of animals that are on the rare or endangered list may be in danger of extinction due to glacier ice retreat. Not by the destruction of habitat, but by the increase of their range.  According to a recent article in the LA Times, the interbreeding of many species could lead to the destruction of individual species in the creation of hybrids.

Large moving bodies of ice known as glaciers form from the accumulation of snow for many years. Glaciers form only in places where snow and ice cover the ground year-round. Wherever snow accumulates, some is lost due to melting, ablation and calving. Where glaciers form, snow remains after these processes. At the moment, the only places on earth that provide the proper condition for glacial formation are the north and south poles and the tops of large mountains. The first year of snow is called a névé. If that layer survives into the next winter, it is called a firn.

Maturing Glaciers

Glaciers form from out of this initial firn; each year new snow piles onto the firn. This accumulation compresses the older firn, creating a dense mat of snow. As the snow compresses it re-crystallizes into grains that are akin to sugar in size and shape. Over many years, the compression increases and these grains grow in size, squeezing the air-pockets out of the snow. As the glacier matures the ice crystal expand to a diameter of a few inches. This process continues for many years, sometimes hundreds or even thousands of years, and causes the layers of ice to become very dense. Eventually the weight of the layers presses nearly all the air out of the ice, giving the glaciers a blue tone.

Snow at the top of a glacier tends to be very brittle and prone cracking while the lower layers of a glacier are more flexible due to the massive amounts of pressure above. This variation causes large crevasses in the top layers of the glacier, which are often hidden under fresh snow.

As glaciers form, their icy mass begins to move downward and outward. Glaciers can be classified as either a valley or continental glacier. Valley glaciers move through valleys as the name suggests. the term continental glacier refers to glacial ice-sheets that expand outward in all directions. The movement of all glaciers is due to two mechanisms: spreading and basal slips. Spreading occurs when there is an internal deformation within the glacier; when the glacier becomes unevenly balanced at any point within its icy mass the glacier regains its balance through spreading outward and flattening. When a glacier is on a slope, it is prone to basal slips. If a thin layer of water at the bottom of the glacier melts, the pressure from the upper layers can cause the glacier to slide down the slope, using the reduced friction of the water to glide smoothly.