Why are deadly ice floes near Antarctica killing so many creatures?

The term deadly ice floes in Antarctica sounds very scary. It is said that there are ice cubes on the seabed of Antarctica. It is a very rare natural phenomenon that only occurs under the seabed of the North and South Poles of Antarctica. Earth. So how did Antarctica’s deadly ice cubes form? And why can he kill so many creatures?

When Antarctic ice cubes form, the temperature at sea level is too low, then the sea water will begin to freeze, resulting in part of the salt contained in sea water. analyze, which leads to the formation of ice. The salinity of the seawater around the block increases. On the one hand, this high-salinity seawater has a lower freezing point and, on the other hand, its density is relatively high. Therefore, when the temperature near the ice drops below the freezing point of waterordinary sea, it still does not freeze. , and due to its high density it continues to freeze. It sinks, causing the temperature of the seawater to drop below freezing and solidifies. This process will continue to occur, so it quickly grows downward to become an ice cube.

During the process of rapid condensation, many organisms on the seabed will die of cold, which will also threaten the normal navigation of ships or submersibles at sea, especially in the minefields and mines. If it comes into contact with an ice cube, it will explode, which is very harmful to all fish. In the process of killing seabed organisms by ice cubes, the ice cubes will continue to sink to the bottom of the sea, and over time the frozen area will continue to increase and gradually expand outward. Because the densityIf ice cubes are higher than sea water, salt water will sink quickly. The surrounding seawater will freeze quickly when it encounters cold salt water. Therefore, when the ice cubes reach the seabed, some of the surrounding seafood or other creatures will be. frozen immediately.

Before the discovery of the Antarctic ice floes, many scientists believed that life could originate in warm oceans, but some scientists had a different view because they believed that seashore delays created life . environment necessary for life, and Antarctic ice cubes are also milk stones in the sea, and then promote the transformation of salt water and sea ice, which can give rise to life. Therefore, the world's oldest life may have appeared and originated in the polar oceans. underwater ice cubes.

Salt water iceformed by the freezing of seawater

Sea ice is a mixture of freshwater ice crystals, "brine" and salt-containing bubbles, including sea ice. fresh water of the continents. (glaciers and river ice) and salt water ice formed by the direct freezing of sea water generally refer to the latter. Broad sea ice also includes river ice, icebergs, etc. in the ocean.

Salt water ice is a mixture of solid ice and brine (including some salt crystals), and its salinity is 2~ lower. than sea water. 10‰, the physical properties (such as density, specific heat, heat of solution, latent heat of evaporation, thermal conductivity and expansion) are different from those of ice d fresh water.

Classification editor

According to the stage of development, it can be divided into six categories: virgin ice, Nile ice, glace in cakes, early ice cream, year-old ice cream, and old ice cream; according to the state of movement, it is divided into two categories: fixed ice and drifting ice. Fixed ice is frozen on the coast, seabed or island. At the same time, it can rise and fall with the sea surface and extend several meters or hundreds of kilometers from the sea. Drifting ice floats on the surface of the sea and moves everywhere with the wind and currents. During the process of sea ice freezing and melting, it will cause changes in sea conditions; drifting ice will affect vessel navigation and damage offshore structures.

By stages of formation and development

Sea ice initially formed by primary ice is made up of fine ice crystals in the shape of needles or flakes; a large number of ice crystals condense and aggregate to form an aggregation. form a sticky shape orspongy Ice, snow falling to the sea surface where the temperature is near freezing, can form sticky ice without melting. On the fluctuating sea surface, the freezing process is relatively slow, but the ice formed is relatively hard and freezes into so-called lotus leaf ice.

Ice skin is a layer of ice on the sea surface formed by direct freezing of the calm sea surface or by continuous freezing of primary ice. It is about 5 centimeters thick and relatively fragile, easily broken into thin rectangular icicles by sea wind or ocean currents.

The primary ice of the Nile Ice continues to grow and freezes into a thin layer of elastic ice with a thickness of about 10 cm. Under the action of external force, it is easy to bend and break into rectangular ice cubes. The thin cake-shaped broken ice slices collide andtighten under the action of external forces, and their edges rise. in a circular ice cube tray with a diameter of 30 cm to 3 m and a thickness of approximately 10 cm. On calm seas, it can also form directly from primary ice.

Endless sea ice

Lotus leaf ice is an ice floe with a diameter of between 30 cm and 3 meters and a thickness of about 10 cm. On calmer seas, young ice may be frozen directly into lotus leaf ice. Lotus leaf ice can also form after large pieces of ice skin or Nile ice break off. The edge of the lotus leaf ice collides with other ice blocks, forming a circle of bulges, and the shape is approximately round, so it looks like lotus leaves on the sea, so we calls it lotus leaf ice cream.

In the initial phase, Nile ice cream or ice cakeswere directly frozen together to form a layer of ice about 10 to 30 cm thick. Mostly off-white. One-year ice is thick ice formed from the initial ice, with a thickness of 30 cm to 3 m. It doesn't last more than one winter. Old ice Ice that has not melted after at least one summer. Characteristically, the surface is smoother than annual ice.

Gray ice, gray and white ice and white ice. When the cold continues, the primary ice, Nile ice, ice skin and lotus leaf ice will mix and the thickness will continue to increase. When the thickness reaches 10 to 15 centimeters, the surface of the ice is predominantly gray and is called gray ice. Gray ice is fragile and fragile. When pressed, it breaks and overlaps, increasing its thickness. When the thickness increases to 15 to 30 centimeters, the color of the ice changes from gray to off-white, calledoff-white ice cream. When the thickness exceeds 30 centimeters, the color becomes white, the surface is uneven, and the shape becomes irregular. Floating ice is then called white ice. [2]?

By movement

Fixed ice is frozen ice on coasts, islands or the sea floor. When the tide level changes, rising and falling movements can occur. More than near coasts or islands, its width can extend over several meters or even hundreds of kilometers from the coast. Fixed ice more than 2 m above the sea surfaceThis is called an ice shelf; the narrow strip of fixed ice attached to the coast cannot rise or fall with the tide. This is the remnant of the fixed ice stream and is called an ice foot. Stranded ice is also a type of fixed ice.

Drifting (floating) ice, i.e. ice that floats freely on the sea and can drift with wind and seaants, is called drifting ice. It can be made up of blocks of ice of different sizes and thicknesses, but icebergs, which are huge masses of ice that slide into the ocean after breaking off from continental glaciers or ice shelves and which found more than 5 m above the sea surface, are not part of it.

If the area of ​​drifting ice is less than 1/10 to 1/8 of the sea surface, the maritime area where free navigation is possible is said to be open water when there is no no drifting ice, even if icebergs appear, it is also called an ice-free zone; the density is 4/10. Those with a density of ~6/10 are called sparse drifting ice, and drifting ice is generally not connected to those with a density of; 7/10 or more are called dense (connected) drifting ice. Under certain conditions, for example when drifting ice breaks and squeezes togetherIn others, ice ridges or mounds of ice can form, sometimes reaching a height of more than 20 meters. [2] ?