19.1: What Is a Glacier?

What Is a Glacier?

A glacier Links to an external site. is a long-lasting accumulation of ice and snow that is large enough to flow down slope under the influence of its own weight. Typically, glaciers are classified by their size and location. Glaciers will develop in areas where 1) the average annual temperatures are close to freezing (32°F or 0°C), 2) the winter season produces significant accumulations of snow, and 3) the temperatures throughout the year remain low enough to retain any of the winter snow accumulation through to the following winter season. Should these criteria be met over multiple decades, the continued accumulation of snow will generate a large enough mass to induce a change from snow to glacial ice. Overall, glaciers are an important component of the cryosphere Links to an external site. and are sensitive indicators of changing climate (see Chapter 20 for additional information).

A person who studies glaciers is typically referred to as a glaciologist. Glaciology is the study of snow and ice and their physical properties. Glaciologists analyze the formation, movement, and effects of the different kinds of glaciers, for example alpine and arctic glaciers, ice caps, ice sheets, and ice shelves. A large part of the research conducted by glaciologists analyzes how glaciers and ice caps move and change in response to climate change and how these changes in turn influence climate and the surrounding environment. Therefore, many glaciologists are also considered climate scientists. Like many other geoscientists, working with other disciplines is common, with a heavy influence from both math and technology. Many are employed by universities where they teach and/or do research, state and federal agencies, including geological surveys, like the California Geological Survey Links to an external site. or United State Geological Survey (USGS) Links to an external site.. Additional career pathways include environmental policy and legislation and consulting, via the private sector or state and federal agencies. Many of these career options require a college degree and postgraduate work. If this pathway is of interest to you, talk to your geology instructor for advice. We recommend completing as many math and science courses as possible. Also, visit National Parks Links to an external site., CA State Parks Links to an external site., museums, gem & mineral shows, or join a local rock and mineral club. Typically, natural history museums will have wonderful displays of rocks, including those from your local region. Here in California, there are a number of large collections, including the San Diego Natural History Museum Links to an external site., Natural History Museum of Los Angeles County Links to an external site., Santa Barbara Museum of Natural History Links to an external site., and Kimball Natural History Museum Links to an external site.. Many colleges and universities also have their own collections/museums.