The Antarctide: A Kingdom Of Ice And Snow II.
In general, the Antarctide is a continent with rather high altitude, because the average surface height above sea level exceeds 2000 metres, and in the centre of this continent, the height reaches even 4000 metres above sea level. Standard glacier cover of mainland forms substantially considerable part of this height. Only 0,3% of this continent, i.e. approx 40 thousands of square kilometres, is without ice cover, mostly in West Antarctide and also in Transantarctic Mountains. The Transantarctic Mountains, passing through the whole continent, divide Antarctide into two parts – West and East Antarctide. Both parts have different origin and are even of diverse geological structure. In its eastern part, a high plateau is to be found. It is the biggest elevation of its ice cover, situated in the height of 4100 metres above sea level.
As this western part, it is a group of mountaneous islands, connected with each other by ice. The Antarctic Ands are placed on Pacific coasts, whereas its height exceeds 4000 metres. Anyway, the highest point of the continent - Vinson Massif, on Sentinel Range, inside Ellsworth Mountain Range, reaches the height of 4892 metres above sea level. Except of this, in West Antarctide, the deepest point of the whole continent could be found. It is Bentley Ditch, full of the ice. Its depth makes 2555 metres.
The Antarctide Flora and Fauna World
Despite this fact that practically the whole continent is covered with ice (glaciers), the sea-waters around are full of nourishment, in a form of plants and vertebrateless, which present a food for big populations of fish, penguins, sea-birds, seals or whales. Anyway, the Antarctic live organismus differ from those, living in tropical or temperate zones with a lot of aspects, such as: big bodies, small growth or small number of species. Moreover, they are very good adapted to rough environment conditions, where they live. So, for instance, the sorts of fish product special albumens presenting an effect as natural means against freezing over.
So, in the Antatctide, you can meet mosses, lichens or mushrooms, from vertebrateles sorts, some small kinds of insects. In less cold areas of north-west part of the continent, some places with a bit of grassy copse are existing. In Antarctide, many lakes are situated, where unusual micro-organismus are hidden, including rare sorts of sea-weeds, microbes or Protozoa. Nearly 75 from 80-100 sorts of Antarctic depth fish belong to group of Nototheniiformes. Most of them are slow, with big heads and conic bodies. These sorts of fish are often occured in littoral sea-waters. The octopuses are of very big importance for Antarctic ecological system. They are a source of nourisment for whales, seals, penguins, sea-birds and fish. So, for instance, the whales from southern hemisphere need for consumption approx. 50 millions of octopuses each year.
This quantity presents approx. 75% of standard fishing out of the world. In the Antarctide, any other dry-land mammals nor fresh air sorts of fish could be found. Nevertheless, each spring, the coasts of the Antarctide are awaken with return of millions of sea-birds. With their arrival, the end of long and dark polar winter comes. At first, the penguins come, in order to overcome even 59 kilometres, in order to reach and find their breeding places. Afterthat, the other birds (such as sand-runners) come flying from the open sea. Most of sorts of birds return towards the same places as in past. The birds clean the places of snow, if necessary, and consequently, they construct their breeding places. Most of sea-birds build their nests among rocks.
The number of birds, (around rocky banks and littoral islands), is estimated to approx. one hundred millions, whereas this quantity is represented there with penguins, (three sorts at least), some sorts of sand-runners, sea-gulls or terns. It is an interesting fact that the penguins present approx. 85% of total number from all sorts of birds.
The body-length of most penguins makes mostly 60-70 cm but even the biggest occure there. Imperial penguin is the biggest one. Its height reaches 100 cm and weight makes up to 1 kgs.The penguins build their nests in colonies, with a number of approx. 80 thousands of individuals. Most of birds build their nests from stones, and their breeding places are filled in with one or two eggs.
As in the Antarctide, covered with snow and ice, no nourishment could be found, the penguins are forced to get it from the sea. This activity takes them most of their time. The penguins are swimmers of first-class level. They are able to dive into great depth. So, in case of imperial penguin, it is approx. 250 metres. Their feet as well as their tails function as a rudder , and their fins drive them ahead. Small sorts of fish and crils serve as everyday penguins´ food.
The crils are small sea-crustaceans, approx.of five centimetres dimensions. The crils present main nourishment for whales or penguins as well as for different sorts of seals. During winter, the growth of sea-weeds and crils is stopped, and it is speeded up in the spring. Within this year season, in the course of ice-thaw, more light comes into nutrients and so called „spring flower“ - i.e. water colouring into green shade is appearing.
Text: Maxim Kucer
Translation: ing Jan Jonáš
Photo: Wikipedia.org - Dave Pape, Mtpaley, Joe Mastroianni, Vincent van Zeijst, Avenue
Discussion at the article (0) |
Related Articles
The Mountains Of Antarctica
Guide:
Important Information:
Information and warnings on travelling abroad is to be found HERE.