Last updated A layer of cryoconite on the surface of a glacier.
Cryoconite is powdery windblown dust made of a combination of small rock particles, soot and microbes[1] which is deposited and builds up on snow, glaciers, or ice caps. The darkening, especially from small amounts of soot, absorbs solar radiation melting the snow or ice beneath the deposit, and sometimes creating a cryoconite hole.[2] Cryoconite may contain dust from far away continental deserts or farmland, particles from volcanic eruptions or power plant emissions, and soot. It was first described and named by Nils A. E. Nordenskiöld when he traveled on Greenland's icecap in 1870.[3] During summer, cryoconite holes frequently contain liquid water and thus provide a niche for cold-adapted microorganisms like bacteria, algae and animals like rotifers[4] and tardigrades to thrive. Cryoconite typically settles and concentrates at the bottom of these holes creating a noticeable dark mass.
Soot decreases the reflectivity, or albedo of ice, increasing absorption of heat. Cryoconite is constantly being added to snow and ice formations along with snow. It is buried within the snow or ice, but as the snow or ice melts increasing amounts of dark material is exposed on the surface, accelerating melting.[3]
Measuring a Cryoconite hole, Longyearbreen glacier (Longyear Valley)
A glacier is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such as crevasses and seracs, as it slowly flows and deforms under stresses induced by its weight. As it moves, it abrades rock and debris from its substrate to create landforms such as cirques, moraines, or fjords. Although a glacier may flow into a body of water, it forms only on land and is distinct from the much thinner sea ice and lake ice that form on the surface of bodies of water.
An ice core is a core sample that is typically removed from an ice sheet or a high mountain glacier. Since the ice forms from the incremental buildup of annual layers of snow, lower layers are older than upper ones, and an ice core contains ice formed over a range of years. Cores are drilled with hand augers or powered drills; they can reach depths of over two miles (3.2 km), and contain ice up to 800,000 years old.
A polar ice cap or polar cap is a high-latitude region of a planet, dwarf planet, or natural satellite that is covered in ice.
A dirt cone is a type of depositional glacial feature. Dirt cones are not actually made entirely of dirt. They have a core of ice, snow, or firn that gets covered with material and insulated. The material, if it is thick enough, will protect the underlying core from ablation. The thickness of material needed to insulate the core is called the “critical thickness.” If the material is less thick than the critical thickness, it will actually speed up erosion of the core through ablation. This is called “indirect ablation.” The cone would then begin melting and shrinking away.
The Greenland ice sheet is a vast body of ice covering 1,710,000 square kilometres (660,000 sq mi), roughly near 80% of the surface of Greenland. It is sometimes referred to as an ice cap, or under the term inland ice, or its Danish equivalent, indlandsis. An acronym, GIS, is frequently used in the scientific literature.
Ice algae are any of the various types of algal communities found in annual and multi-year sea or terrestrial ice. On sea ice in the polar oceans, ice algae communities play an important role in primary production. The timing of blooms of the algae is especially important for supporting higher trophic levels at times of the year when light is low and ice cover still exists. Sea ice algal communities are mostly concentrated in the bottom layer of the ice, but can also occur in brine channels within the ice, in melt ponds, and on the surface.
Melt ponds are pools of open water that form on sea ice in the warmer months of spring and summer. The ponds are also found on glacial ice and ice shelves. Ponds of melted water can also develop under the ice.
Chemically, black carbon (BC) is a component of fine particulate matter. Black carbon consists of pure carbon in several linked forms. It is formed through the incomplete combustion of fossil fuels, biofuel, and biomass, and is one of the main types of particle in both anthropogenic and naturally occurring soot. Black carbon causes human morbidity and premature mortality. Because of these human health impacts, many countries have worked to reduce their emissions, making it an easy pollutant to abate in anthropogenic sources.
Watermelon snow, also called snow algae, pink snow, red snow, or blood snow, is a phenomenon caused by Chlamydomonas nivalis, a species of green algae containing a secondary red carotenoid pigment (astaxanthin) in addition to chlorophyll. Unlike most species of fresh-water algae, this species appears to be cryophilic (cold-loving) and thrives in freezing water.
Ablation zone or ablation area refers to the low-altitude area of a glacier or ice sheet below firn with a net loss in ice mass due to melting, sublimation, evaporation, ice calving, aeolian processes like blowing snow, avalanche, and any other ablation. The equilibrium line altitude (ELA) or snow line separates the ablation zone from the higher-altitude accumulation zone. The ablation zone often contains meltwater features such as supraglacial lakes, englacial streams, and subglacial lakes. Sediments dropped in the ablation zone forming small mounds or hillocks are called kames. Kame and kettle hole topography is useful in identifying an ablation zone of a glacier. The seasonally melting glacier deposits much sediment at its fringes in the ablation area. Ablation constitutes a key part of the glacier mass balance.
Terra Cimmeria is a large Martian region, centered at 34.7°S 145°E and covering 5,400 km (3,400 mi) at its broadest extent. It covers latitudes 15 N to 75 S and longitudes 170 to 260 W. It lies in the Eridania quadrangle. Terra Cimmeria is one part of the heavily cratered, southern highland region of the planet. The Spirit rover landed near the area.
A supraglacial lake is any pond of liquid water on the top of a glacier. Although these pools are ephemeral, they may reach kilometers in diameter and be several meters deep. They may last for months or even decades at a time, but can empty in the course of hours.
Ice sheet dynamics describe the motion within large bodies of ice, such those currently on Greenland and Antarctica. Ice motion is dominated by the movement of glaciers, whose gravity-driven activity is controlled by two main variable factors: the temperature and the strength of their bases. A number of processes alter these two factors, resulting in cyclic surges of activity interspersed with longer periods of inactivity, on both hourly and centennial time scales. Ice-sheet dynamics are of interest in modelling future sea level rise.
Rotten ice is a loose term for ice that is melting or structurally disintegrating due to being honeycombed by liquid water, air, or contaminants trapped between the initial growth of ice crystals. It may appear transparent or splotchy grey, and it is generally found after spring or summer thaws, presenting a danger to those traveling or spending time in outdoor recreation. The increase of rotten ice vs. solid ice in the Arctic affects ocean-atmosphere heat transfer and year-to-year ice formation, as well as the lives of the Inuit, sea mammals such as walrus and polar bear, and the microorganisms that live inside the ice.
The Arcadia quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The quadrangle is located in the north-central portion of Mars’ western hemisphere and covers 240° to 300° east longitude and 30° to 65° north latitude. The quadrangle uses a Lambert conformal conic projection at a nominal scale of 1:5,000,000 (1:5M). The Arcadia quadrangle is also referred to as MC-3.
The Thaumasia quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Thaumasia quadrangle is also referred to as MC-25 . The name comes from Thaumas, the god of the clouds and celestial apparitions.
The planet Mars has two permanent polar ice caps. During a pole's winter, it lies in continuous darkness, chilling the surface and causing the deposition of 25–30% of the atmosphere into slabs of CO2 ice (dry ice). When the poles are again exposed to sunlight, the frozen CO2 sublimes. These seasonal actions transport large amounts of dust and water vapor, giving rise to Earth-like frost and large cirrus clouds.
Subglacial streams are conduits of glacial meltwater that flow at the base of glaciers and ice caps. Meltwater from the glacial surface travels downward throughout the glacier, forming an englacial drainage system consisting of a network of passages that eventually reach the bedrock below, where they form subglacial streams. Subglacial streams form a system of tunnels and interlinked cavities and conduits, with water flowing under extreme pressures from the ice above; as a result, flow direction is determined by the pressure gradient from the ice and the topography of the bed rather than gravity. Subglacial streams form a dynamic system that is responsive to changing conditions, and the system can change significantly in response to seasonal variation in meltwater and temperature. Water from subglacial streams is routed towards the glacial terminus, where it exits the glacier. Discharge from subglacial streams can have a significant impact on local, and in some cases global, environmental and geological conditions. Sediments, nutrients, and organic matter contained in the meltwater can all influence downstream and marine conditions. Climate change may have a significant impact on subglacial stream systems, increasing the volume of meltwater entering subglacial drainage systems and influencing their hydrology.
The Dark Snow Project is a field and lab exploration to measure the impact of changing wildfire and industrial soot and snow microbes on snow and ice reflectivity.
Aonia Terra is a region in the southern hemisphere of the planet Mars. It is named after a classical albedo feature Aonia, that was named after the ancient Greek region Aonia.
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Measuring a Cryoconite hole, Longyearbreen glacier (Longyear Valley)
Taking a sample, Longyearbreen glacier
