An ice dune, also called an ice ridge or an ice foot, is a formation of

ice Ice is water that is frozen into a solid state, typically forming at or below temperatures of 0 ° C, 32 ° F, or 273.15 K. It occurs naturally on Earth, on other planets, in Oort cloud objects, and as interstellar ice. As a naturally oc ...

that accumulates on the shores of many

arctic The Arctic (; . ) is the polar regions of Earth, polar region of Earth that surrounds the North Pole, lying within the Arctic Circle. The Arctic region, from the IERS Reference Meridian travelling east, consists of parts of northern Norway ( ...

beaches and is also common along the shores of the

Great Lakes The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes spanning the Canada–United States border. The five lakes are Lake Superior, Superior, Lake Michigan, Michigan, Lake Huron, H ...

during the

winter Winter is the coldest and darkest season of the year in temperate and polar climates. It occurs after autumn and before spring. The tilt of Earth's axis causes seasons; winter occurs when a hemisphere is oriented away from the Sun. Dif ...

.French 2007, p. 273. Ice dunes are not to be confused with ice shoves, which accumulate on bodies of water then push their way on shore, carrying sediment with them and deforming the shoreline.

Cause

An ice dune is produced by ice washing ashore, snowfall, and the gradual freezing of wave spray that accumulates on to the shore. They form when the air temperature is below freezing and the water temperature is near freezing. Ice dunes are commonly at least tall, but the dune's size depends on the beach and the weather. The

tidal range Tidal range is the difference in height between high tide and low tide. Tides are the rise and fall of sea levels caused by gravitational forces exerted by the Moon and Sun, by Earth's rotation and by centrifugal force caused by Earth's prog ...

, the ''storminess'' of the water and the topography of the beach all can affect the size of the dunes.French 2007 p. 276. The dunes will also stop forming if the body of the water they border freezes over, which often happens on

Lake Erie Lake Erie ( ) is the fourth-largest lake by surface area of the five Great Lakes in North America and the eleventh-largest globally. It is the southernmost, shallowest, and smallest by volume of the Great Lakes and also has the shortest avera ...

. Ice dunes will usually break up in the early stages of spring thaw.

Effects

Ice dunes are important in formations, such as sandspits and sand

isthmus An isthmus (; : isthmuses or isthmi) is a narrow piece of land connecting two larger areas across an expanse of water by which they are otherwise separated. A tombolo is an isthmus that consists of a spit or bar, and a strait is the sea count ...

es, that could be

eroded Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust and then transports it to another location where it is deposited. Erosion is disti ...

by wave action. An example of a Great Lakes sandspit is

Presque Isle State Park Presque Isle State Park ( ) is a List of Pennsylvania state parks, Pennsylvania State Park on an arching, sandy peninsula jutting into Lake Erie, west of the city of Erie, Pennsylvania, Erie, in Millcreek Township, Erie County, Pennsylvania ...

Erie, Pennsylvania Erie is a city on the south shore of Lake Erie and the county seat of Erie County, Pennsylvania, United States. It is the List of municipalities in Pennsylvania, fifth-most populous city in Pennsylvania and the most populous in Northwestern Pen ...

. When the dunes form, they form a barrier between the waves and the shore and prevent the waves from reaching the shore, keeping the sand in place. Because of the way ice dunes form, they are inherently weak and filled with cracks and air pockets. People who venture out onto the dunes sometimes will fall through. If the dune extends out over the water, persons who do this can fall through the dune and into the freezing water underneath; if this happens,

hypothermia Hypothermia is defined as a body core temperature below in humans. Symptoms depend on the temperature. In mild hypothermia, there is shivering and mental confusion. In moderate hypothermia, shivering stops and confusion increases. In severe ...

and death by

drown Drowning is a type of suffocation induced by the submersion of the mouth and nose in a liquid. Submersion injury refers to both drowning and near-miss incidents. Most instances of fatal drowning occur alone or in situations where others presen ...

ing are urgent, immediate dangers.

References

Sources

* Dunes Geomorphology Snow or ice weather phenomena Water ice {{geomorph-stub

Cause

Effects

See also

References

Sources