![]() While the frozen waves grace the shorelines of Nantucket, where the temperatures will inevitably increase as the seasons change (unless the ice queen really is in town), luckily we have photographers like Nimerfroh willing to brave the cold and deliver us such icy treats. The National Snow and Ice Data center reports that "sea ice covers 25 million square kilometers of the planet's surface, or two and a half times the area of Canada." Sea ice is more commonly found in polar oceans like the ones that surround the Arctic and Antarctica, where it helps to regulate the earth's climate. Eventually, if the temperature remains low long enough, the patches fuse to form a sheet. But because the water was in perpetual motion, the frazil ice formed little ice patches that bump into each other and give rise to the slushy appearance. If the Nantucket shoreline was calm, then the ice that formed on top would have been smooth and dark at first, getting whiter as it thickened. So, in addition to looking like a frozen wave, after a while the ice that forms actually becomes drinkable.Īside from the temperature, the motion of the ocean matters for how the frozen waves appear, according to the National Snow and Ice Data Center. As that happens, salt, which doesn't freeze, gets left behind. So when this happens, like when it did recently in Nantucket, loose needle-like ice crystals called frazil begin to form. In the summer, this ice melts back.Sea ice covers 15% of the earth's water at some point in the year, according to the National Oceanic and Atmospheric Administration. In Antarctica, sea ice forms in the winter, doubling the area of the continent. Why doesn't it just keep getting thicker and thicker? Multi-year ice eventually enters equilibrium: the amount of new ice being formed on the bottom of the layer in winter is exactly balanced by the loss due to melting off the top in summer. This ice ranges in thickness from 15 feet to 25 feet. In the central Arctic, the ice never thaws completely in summer, and thus it is known as multi-year ice. Ice that forms each winter and melts each summer is known as annual ice, and is usually about six feet thick. As the surface temperature continues to drop, the ice forms a solid layer and is then called pack ice. This film is strong enough to support the weight of a seabird, and can ripple with the waves passing beneath. As this soup thickens, a thin film of ice known as grease ice forms. A soupy crystalline mixture known as frazil ice begins to form in the upper layer. ![]() At the onset of winter, cold air chills the surface waters until a relatively large layer of water at -2☌ has formed on the surface. ![]() But here, ice forms a permanent, impenetrable canopy over a completely dark and cold (around -1.9) environment. The density of seawater steadily increases as it cools, until reaching the freezing point of around -2☌ (although this depends on how salty the water is). This ice-covered cavity contains an ocean nearly equal in volume to the North Sea. Seawater, because of the salt it contains, freezes in a different manner compared to fresh water. This kind of ice is formed by the freezing of seawater. The other kind of ice is sea ice, also called pack ice. Based on their sizes, they are given different names, such as growler and bergy bit. Most bergs formed in Canada and Greenland stay in the eastern Arctic, eventually being carried into the Atlantic via Davis Strait and melting away. Since 90% of an iceberg is below the surface of the water, they travel with ocean currents and not the winds. The Greenland ice sheet and the Ellesmere, Devon, and Baffin Island glaciers in Canada account for the vast majority of arctic bergs. Icebergs are chunks of floating ice that have "calved" (broken off) from a glacier. Its rapid disintegration in early 2002 has been attributed to global warming. Scientists sometimes name these large masses of ice, such as Antarctica’s Larsen B ice shelf. Where glaciers meet the sea, the ice can flow out onto the ice, forming a thick, floating ice shelf. The Antarctic ice sheets are the largest, containing 85% of the world’s ice. Antarctica, Greenland, and parts of Canada have glaciers. Thus, they are composed entirely of fresh water. Glacier ice is formed from compacted snow. GlaciersĪlthough there are many different kinds of ice, it can be divided into two very basic types based on the method of formation. The Arctic and Antarctic each have both types of ice-read more to learn how they differ. Newly formed sea ice, however, can be thin and rubbery like a piece of pizza dough. Icebergs, like the one that sank the Titanic, can be as big as a house. Other Expeditions Highlighting WHOI Research.Expedition to Stellwagen Bank National Marine Sanctuary.How do polynyas help feed emperor penguins?.Why is pressure different in the ocean?.What’s the difference between climate and weather?.How does ocean warming affect fisheries?.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |