This entry is intended to accompany current and future entries to the Cryosphere Chronicles, which is a travel journal, of sorts, featuring my experiences with glaciers around the world. As I write the Chronicles, there will inevitably be words that are unfamiliar to some that I don't bother to define in each entry, so I will list several here for easy reference.
These definitions are my own, some interpretations of other official glossaries and some gathered from texts or even from guides around me. I will continue to keep these updated as I use new terms in entries to the Chronicles.
Cryosphere - The Cryosphere is the Earth's system of ice. It is similar and closely linked to the Hydrosphere. The Cryosphere includes the ice sheets of Greenland and Antarctica, all of the Earth's icefields, glaciers, sea ice, and frozen lakes, rivers, and waterfalls. The Cryosphere plays a large role in all of the planet's systems and in providing drinking water to people around the world.
Glacier - A slowly moving mass of ice created from multiple years of accumulation and compacting of snow.
- Alpine Glacier -Any glacier starting high in the mountains.
- Valley Glacier -A glacier confined to a steep sided valley
- Tidewater Glacier -Any glacier that flows to the ocean. Tidewater glaciers are those you see calving icebergs into the ocean.
- Peidmont Glacier -A glacier flowing through a valley that opens onto a relatively flat plain, spilling out into a circular spoon shaped lobe on the plain below. The Malaspina Glacier is a good example of this.
- Hanging Glacier - A glacier clinging to the steep wall of a mountain or valley. As ice flows down, avalanches and ice fall from the steep wall to valleys below.
- Cirque Glacier - A high mountain glacier occupying a rounded cirque, or bowl-like feature of a mountain to.
- Rock Glacier - There seems to be some discrepancies in this term. A recent book I read, "Glaciers: The Politics of Ice," described two types: A Rock Glacier being a glacier that actually contains many rocks within the glacier ice, as in an area where rock slides often occur in the accumulation zone, filling the snow with rock debris as the glacier forms. Also frozen, flowing ground like permafrost on a steep slope may be sometimes considered a Rock Glacier. The second type being a Rock Covered Glacier, which many sources just call a Rock Glacier. A Rock Covered Glacier would be a glacier that is mostly clear or white ice, but flowing through such an area that would cause debris and rock to cover all or most of the white ice.
- Icefield - A large area of Ice often high in a mountain range that spawns many glaciers. The Harding Icefield is a well known example, and it spawns the Exit Glacier, among many others in Southern Alaska
- Ice Sheet -Also known as a continental glacier, Ice Sheets are massive (50,000 sq km +) and currently only found in the polar regions (Antarctica and Greenland), though in the last ice age three major Ice Sheets covered most of North America.
Crevasse - A large crack formed by a pressure difference in the ice causing it to split apart. Common in icefalls or along the sides of glaciers where ice is moving at different speeds.
Moulin -French word for 'Mill', a moulin is a hole carved out by water milling it's way down into a weakness in the glacier ice. A moulin may lead underneath the glacier or out the side, wherever water can find a way downstream.
Serac - A standing fin or ridge often created as multiple crevasses separate the ice.
Icefall - Much like a waterfall, when glacier ice flows over a rapid drop in the earth, the ice becomes broken into crevasses and seracs as it rapidly accelerates downward.
Firn Line - The line separating the accumulation and ablation zones, marked by unmelted snow in the peak of summer.
Kettle Pond - A pond or lake created by ice left underground from a receding glacier. When the ice underground melts, it creates a depression forming the pond/lake.
Terminus - The end, or toe, of the glacier
Nunatak - a peak or mountain seemingly sticking up out of the middle of a glacier, surrounded by ice.
Moraine - Glacially eroded rock and/or soil often of mixed sizes in current or formerly glaciated terrain.
- Lateral Moraine - Rock debris falling onto the sides of a glacier as it flows through a valley and erodes the walls around it.
- Medial Moraine - As two glaciers flow together, their two lateral moraines will merge and create a line down the center of the larger glacier downstream.
- Terminal Moraine - As glaciers move downstream they act as conveyor belts moving debris down with them. As the glacier melts at it's terminus the debris that is deposited there is called a terminal moraine.
- Recessional Moraine - When a glacier recedes, it sometimes creates new, smaller moraine piles similar to a Terminal moraine
Mass Balance - Accumulation vs. Ablation - if more snow falls than melts, there is a positive mass balance. If ice melts faster than snow accumulates, there is a negative balance.
Accumulation - Snowfall adding to the mass of a glacier.
Ablation - Melting taking away from the mass of a glacier.
Advancing - When a glacier's terminus is pushing forward, typically associated with a net gain in mass, but not always. It is possible for tidewater glaciers especially to advance even though they have a negative mass balance due to surface melting.
Receding -When a glacier is melting faster than it is accumulating mass - the terminus melts away and no new ice pushes forward to replace it.
Down-wasting - A net loss of mass in the depth of glacier ice due to melting. May or may not be accompanied by recession.
- Cryosphere refers to any portion of the Earth's surface where water is in solid form, including glaciers, ice caps, ice sheets, sea ice, snow cover, frozen rivers, lakes, and permafrost. The Cryosphere is closely linked to the Hydrosphere and plays a crucial role in the ecosystem and our everyday lives.
- I've chosen the name because Cryosphere encompasses a wide range of ice around the world. This blog is meant to chronicle not all glaciers, but those that I experience and photograph in my travels. My vision is to visit and write about as many glaciers and other ice forms as possible while I pursue knowledge and share experiences of a beautiful world of ice. I hope you enjoy the photographs and follow along as I go!