Physical features of the polar environment
Ice
Antarctica is manly made up of ice and snow so it be would likely to see all sorts of ice phenomenon's and forms of it. Ice shelfs Ice is less dense than water and because the ice sheets generally rest on a bed below sea level, there comes a point where it begins to float. either the ice shelves stay attached to the ice sheet as an ice shelf, or breaks away as an iceberg. Being afloat, ice shelves experience no friction under them, so they tend to flow even more rapidly than ice streams, up to 3 km per year. Much of Antarctica is fringed by ice shelves. Ice sheets The Antarctic ice sheet is the largest single mass of ice on Earth. It covers an area of almost 14 million km² and contains 30 million km³ of ice. Around 90 per cent of the fresh water on the Earth’s surface is held in the ice sheet. ice sheets will flow like a viscous liquid. This means that the ice sheet does not continue to get thicker as new snow falls but, under the action of gravity, flows over and around obstacles toward the sea. The ice sheet acts like a conveyor belt, taking ice from the atmosphere and delivering it back to the sea. Ice stream Ice streams only account for 10% of the volume of the ice sheet. Ice streams are a sizable feature to the antarctic, an ice stream can reach up to 50km wide and 2000m thick. Some flow at speeds over 1000m per year. Permafrost Permafrost refers to anything that is frozen year round, ranging from meters to kilometers in depth. The top is referred to as the "active layer" and may melt during the summer. |
Ice and Rock Antarctica is primarily ice, however, it is also 2% rock. Most of its coastline is fringed with ice shelves. Antarctica also has numerous mountains and ice caves. Its largest ice shelf is about the size of France. In December 2013 scientist found a possible hot spot that sits under Marie Byrd Land, a broad dome at West Antarctica's edge where many active volcanoes are found. The zone was found by using seismic techniques which basically relays on using earthquake waves to build a picture of earths inner core. Beneath Marie Byrd Land the earthquake waves slowdown suggesting that that the rock there is hotter than the rock around it, creating a rock hotspot. Northern Lights The Northern Lights are an astronomical phenomenon that occur when electrons accelerate into the upper atmosphere along Earth's magnetic field lines. They result in amazing curvy lines across the sky. The colours of The Northern Lights depends on the gas e.g. helium - orange/white, neon - red/orange, argon - lavender, krypton - gray/green, and so on. The Northern Lights are determined on the gases in the atmosphere and incoming solar particles tend to collide with different gases at different heights. As the particles pass through they mingle with the atoms and molecules hat result in the dazzling display of lights in the sky. |
The clip above is a bomb replicating what a underwater vocalic eruption would look like.
|
Antarctic Volcanoes
Under thick ice and frigid water, volcanic explosions are shaking the Arctic Ocean floor at depths previously thought impossible, according to a new study a volcano was shown that there was an active at 4 meters below the seafloor.up until now, scientists thought undersea volcanoes only dribbled lava from cracks in the seafloor. The extreme pressure from the overlying water makes it difficult for gas and magma to blast upwards.They estimate that the slow spreading could allow excess gas to build up in pockets of magma beneath the oceanic crust. When the gas pressure gets high enough, it pops like a champagne bottle being uncorked. |