Table of Contents
BEST IELTS Academic Reading Test 35
ACADEMIC READING TEST 35 – PASSAGE – 1
ACADEMIC READING TEST 35
READING PASSAGE – 1
The Eisriesesnwelt Ice Caves
A. Most caves are found in coastal regions, their existence being down to pure water erosion, other common cave formations include those caused by lifting and volcanic lava streams. Eisrisenwelt, which holds the longest known system of ice caves in the world, was not formed by any one of those processes alone, and, in fact, owes its existence primarily to the water-soluble nature of the limestone rock found in the limestone mountains of the Austrain Alps around Salzburg.
B. The Alps themselves, one of the largest mountainous region on earth, which stretch across most of Austria, Germany, Switzerland and on into Italy and France as well, were created by a process called lifting. The African and European tectonic plates moved towards each other. The impact of the eventual collision of the plates resulted in the formation of a large mountainous ridge stretching across the impact line. As the two plates continued to push towards each other, the ridge grew in size, eventually leading to the formation to the cracks, rock displacements and fault lines. Once the Alps were raised, the hollow area formed by pressure cracks started to be worked on by outside influence, especially water and these influences then played their par over millions of years in the creation of the subterranean passage of Eisrisenwelt that we are familiar with today.
C. Rock composition also played an important role in the formation of the alpine caves. Extensive cave systems like Eisriesenwelt tend only to be located in the limestone Alps, primarily on account of limestone being water-soluble, especially when it comes into contact with rain water that has been enriched with organic material. Over time, the limestone which came into contact with rain water broke down and dissolved, leaving large hollow area to form underground. When the caves were first forming a few million years ago, the climate of the region of sub-tropical, meaning the level of solubility was even higher than it is today, so the erosion of the limestone occurred at a higher rate, too.
D. Corrosion is the chemical dissolution of rock. In the case of Eisriesenwelt, when rainwater came into contact with the limestone rock, lime or CaCo3, was being corroded. But water has fewer H+ ions and would not cause lime to dissolve. Only when carbon dioxide or co2 from the air and vegetation is introduced, is an aggressive acid, known as carbonic acid, formed. When this acid permeates the cracks in the limestone, the limestone dissolve. As it dissolves, wider cracks open in the stone allowing more water to pass through, which, in turn, causes greater erosion of the rock. High level of precipitation, characteristic of the alpine region, resulted in greater volumes of water collecting and flowing through the hollow areas of the stone, and faster rates. The greater volume of water and the rate of flow combined eroded the caves further and led to an increasing amount of material being washed away. This resulted in the formation of the spectacular geological features of the Alps, such as the long gorges, shafts and canyons to be found there.
E. In short, the Eisrisenwelt caves were formed as a result of a combination of various factors: primarily lifting, corrosion and water erosion. The caves themselves are unremarkable, though, similar examples being relatively widespread in limestone areas around the world. What set Eisriesenwelt apart are the unique ice formations that are present in a significant amount of the cave expense. Of the millions of known cave systems in the world, relatively few are genuine ice caves in which ice is present year-round. That is what makes the Eisiesenwelt caves so special.
F. Eisriesenwelt is what’s known as a dynamic ice cave system, the other types being static ice caves, as the name would suggest, have a consistent level of ice cover year- round and a fairly even temperature. In winter, the air temperature outside the cave might reach below minus 20 degree celsius for example. When it becomes colder than the air inside the cave, the air in the cave rises to escape and the cold air fills the space left behind. In summer, though, the temperature outside the cave is warmer than it is inside and the cold air in the cave, being heavier than the hot air outside, cannot escape and remains in a cold pocket, keeping the cave at a fairly constant temperature below freezing. Glacier caves are easier to explain; simply the product of melt water carving a route for itself down from the mountain.
G. Dynamic caves are a little different and the basic principle of dynamic ice cave is the chimney effect: the requirement for a cave to have at least two entrances, one at relatively low altitude and the other at a much higher altitude. In winter, when the outside temperature is very low, the (comparatively) warm temperature within the cave system’s rock causes a draft which rises up through the cave towards the uppermost cave entrance. As a result of cold air streaming in from outside, the rock in the lower part of the cave then starts to radically cool. In summer, the outside temperature is much higher than the inside one, so the draft goes the other way, with warm air streaming in from the topmost entrance towards the lower levels. But, before this warm air can reach the lower level of cave, it has cooled considerably, so as a result, the lower levels maintain a fairly constant year-round temperature close to freezing. Consequently, water that seeps into the lower part of the cave tends to freeze causing ice to build up, giving the spectacular ice formations for which the area has become known.
Questions 1-3
Write NO MORE THAN THREE WORDS from the passage for each answer.
1. The majority of caves around the world are found in coastal areas and were formed as a result of what substance acting on rock?
2. What process is responsible for the creation of the large mountainous ridge which stretches across much of Europe, more commonly known as the Alps?
3. Large area of what, were enabled to form by the limestone rock present in parts of the Alps?
Question 4-9
Reading passage has seven sections, A-G
Which section contains the following information? Write the correct letter, A-G.
Some sections may be used more than once; others not at all.
4. How rare ice caves and ice-cave systems are. …………………………
5. How serious weathering of limestone rock in the Alps was responsible for the formation of other features besides caves. ………………..
6. An explanation of why limestone was eroded more quickly in the distant past than it is being today ………………..
7. How the mountain range which is home to the Eisriesenwelt caves was formed………………..
8. How caves with more than one entrance from which air can escape all year round can always remain cold enough in parts for ice to be present ………………………….
9. How rock corrosion and water erosion do not necessarily have to play a direct role in the formation of ice caves………………….
Question 10-13
Choose the correct letter, A,B,C or D.
10. Which type of cave formation is represented in the diagram?
A. Static ice cave in winter
B. Static ice cave in summer
C. Dynamic ice cave in winter
D. Dynamics ice cave in summer
11. Which type of cave formation is represented in the diagram?
A. Static ice cave in winter
B. Static ice cave in summer
C. Dynamics ice cave in winter
D. Dynamics ice cave in summer
12. Which of the following statements is accurate?
A. Air is escaping from dynamics ice caves all year round, but it only escapes from static ice caves when the temperature is cooler inside the cave than it is outside.
B. Air is escaping from dynamics ice caves all year round, but it only escapes from static ice caves when the temperature is warmer inside the cave than it is outside.
C. Air is escaping from dynamics ice cave all year round, but it never escapes from statics ice caves, hence the name “static”
D. Air escapes from dynamics ice caves in winter, whereas wind escapes from static ice caves during the summer months.
13. Which of the following statements is accurate?
A. Dynamics ice caves produce upward air currents in summer and winter.
B. Dynamics ice caves will produce drafts throughout the year.
C. Cold air is channelled downwards through dynamic ice cave in winter
D. Cold air is channelled upward through dynamic ice caves in summer.
Answer key
1. pure water
2. lifting
3. cave systems
4. E
5. D
6. C
7. B
8. G
9. E
10. A
11. D
12. B
13. B
