Reading Passage 2

AVALANCHE!

Nature’s destructive fury is unleashed on mountainsides around the world

A) Hurtling down a mountainside at speeds of up to 300 kilometres an hour, an avalanche is at once both a terrifying sight and a spectacle of nature. The power of gravity pulls the snow mass down the mountain slope, capturing all in its path, from rocks, trees, and ice to, from time to time, human victims. Avalanches are caused by a wide range of factors, including the steepness of the mountainside, the weather, the terrain, the snowpack conditions and human activity. Avalanches occur in all parts of the world, in the northern hemisphere and the southern—wherever there are slopes steep enough for the snow to slide down, sometimes recording as much as 250,000 cubic metres of snow descending at unimaginable speeds and force, destroying all in its path.

B) An avalanche is an occurrence of nature whereby an entire layer of snow, or snowpack, separates naturally, or from human activity, and descends with rapid downward force, building up speed and air pressure ahead of it, with phenomenal destructive force. An avalanche has three main parts, the starting zone, the avalanche track and the runout zone. The starting zone is a volatile area of a slope where snow that is unstable can fracture and separate from the compacted snow and start to move downward. Usually, this occurs high up the slope of a mountain, but can happen anywhere there is a slope, and the usual cause is when the weight or force of the snow is greater than the strength holding it together. The avalanche track is the route the cascading snow follows, and is often a noticeable track following open or chute-like terrain, away from dense growths of trees, which indicates that other avalanches may have occurred, and often ending with large collecting areas where there is an abundance of debris, such as in gullies or flattened open areas. This is known as the runout zone, which is where the snow is usually piled the highest, with mounds of debris deposits.

C) There are three main types of avalanches: wet snow avalanches, dry snow avalanches and slab avalanches. Wet snow avalanches are often thought of as the least dangerous, usually occurring naturally in the spring season because of melting snow from the increasing temperatures. They are considered less dangerous because of the slow speed, due to friction, but can cause significant destruction because of their large mass. Water saturation is a key point, due to the melting, and they pull boulders, earth and vegetation with them. Dry snow avalanches are normally the largest, consisting of an enormous powder cloud masking huge volumes of a rapidly moving snowpack and occur at any time or for any reason. These avalanches can reach speeds of 300 km/hr, and can carry up to 10,000,000 tonnes of snow for incredibly long distances, and often uphill as they come to rest. Finally, some experts consider slab avalanches as the most dangerous, as a slab, or block, of snow separates from the main body of snow and cascades downward. A ‘crown fracture’ appears at the top and ‘flank fractures’ are created vertically, separating the block of snow which speeds downhill, destroying everything. Interestingly, these types of avalanches often leave ‘walls’ carved in the snow where the avalanche has broken away. Slab avalanches account for most related fatalities, and are often caused by human activity, notably skiers.

D) Other factors that can cause avalanches include natural conditions such as wind, weather, composition of the snow, storms, sunlight and moisture. Interestingly, coastal environments limit many of the dangerous aspects of mountainous conditions, with an ongoing stabilization of the snowpack due to a continuous freeze-thaw cycle moderating weather extremes. Very cold temperatures can also cause critical circumstances which give rise to avalanches, by affecting the stability of the snow pack, with differences in ground temperatures contrasting with the ambient air temperature, thus affecting moisture content, crystal formation and varying thicknesses of snow. Storms, be they rain or snow, lead to weight variations, with heavy precipitation on top, and less chance of snow bonding to secure a stable weight-load. And sunlight introduces a number of factors, melting, re-freezing and radiation loss which means significant variations in the heat/cooling process, which impacts on the stability of the snow pack.

E) So, what can be done to prevent, predict or control this unleashing of nature’s destructive forces? In areas where avalanches present a major threat, such as mountainous communities, ski resorts and transportation facilities, there are a number of initiatives being introduced, because holding back Mother Nature has always been a long-held, but not always successful, dream. Explosives are regularly used in mountainous areas, armies being employed to fire high-decibal cannons which trigger shock waves to loosen snow packs, and other concussion devices dropped from helicopters or hand-launched. Protective fences can direct snow build-up to help prevent snow packs being formed, and there is often construction of avalanche dams to re-direct falling snow, or the building of earth mounds to slow the slide of avalanches. Lastly, to protect human life in the possibility of avalanche conditions, snow shelters have been constructed to withstand the impact of the force of snow, shielding human life, vehicle traffic and residential dwellings.

F) Avalanches cannot accurately be predicted, although the conditions can be monitored, studied and assessed. Snow and weather conditions, including temperature, wind and moisture, are a reliable guide, as well as human activity, recent history and forecasts of worsening conditions. However, unfortunately, disasters have occurred. And will continue so. During World War I, between 40,000 and 80,000 soldiers died in the mountainous regions of central Europe, in particular on the Austrian-Italian battlefields, and it has been determined that many were killed as a result of artillery fire, the concussive effects resulting in avalanches. Numerous ski resorts and their communities have unfortunately suffered devastating avalanches, notably in Turkey in 1993, when 43 climbers lost their lives, and in France in 1999, when 12 people were buried under 100,000 tonnes of snow, and in the same year, 31 people died in Austria in one avalanche.

G) There are various classification systems for avalanches, but none that is universally recognized. Canada and the United States use one system, defining risk levels using various factors, while Europe employs a different rating system with different criteria, and other alpine nations utilize varying systems which reflect different aspects of risk and outcomes. Avalanches pose a constant threat, and work is constantly being done to forecast, and mitigate, the risks and outcomes of avalanches. Survival is possible for those caught in this most terrible of natural circumstances, and future work and investigation is vital to ensure the safety of those caught in one of nature’s most destructive unleashings.

Reading Passage 2

You should spend about 20 minutes on Questions 14 –26 which are based on Reading Passage 2.

Questions 14 – 20

Reading Passage 2 has seven sections A – G.

Choose the most suitable headings for sections A – G from the list of headings below.

Write the appropriate numbers i – ix on your answer sheet.

14. Paragraph A
15. Paragraph B
16. Paragraph C
17. Paragraph D
18. Paragraph E
19. Paragraph F
20. Paragraph G

Questions 21 – 24

Classify the following statements as characteristics of

A   wet snow avalanches
B   dry snow avalanches
C   slab avalanches

Write the appropriate letters A – C in boxes 21 – 24 on your answer sheet.

NB  You may use any letter more than once.

21. Generally, there are two main parts to this type of avalanche.
22. This avalanche is common during one particular time of the year.
23. Specific lines demarcating the actual avalanche are formed when it is created.
24. One key point, moisture, is necessary to generate the force to cause the avalanche to break away and begin to move.

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Questions 25 – 26

Choose the appropriate letters A – D and write them in boxes 25 and 26 on your answer sheet.

25. Measures to control avalanches include

1. large weapons being fired in mountainous areas to create huge sound waves to loosen the snow.
2. helicopters being used to blow the snow off mountainsides.
3. teams of men manually moving densely-packed snow away from inhabited areas.
4. avalanche dams stopping falling snow.

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26. The classification systems for avalanches

1. in Canada and the United States differ according to the mountain regions.
2. are used to determine  the possibility of an avalanche.
3. vary in different areas of the world.
4. use the European criteria to classify avalanches.

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Reading Passage 3

THE NON-MILITARY USES OF UNMANNED AERIAL VEHICLES

A) The use of unmanned aerial vehicles has grown dramatically over the past decade or so, in no small part due to the fact that some of these machines are able to remain airborne for longer periods of time than more conventional manned aircraft. At the same time, unmanned aerial vehicles (UAVs), also known as unmanned aircraft systems (UASs), and remotely piloted aircraft (RPAs), nowadays commonly referred to as drones, are generally credited with being both more cost-effective to operate and maintain, as well as safer to use, than piloted aircraft. The term drone may also refer to small electric helicopters fitted with two or more rotors which are flown by remote control.

B) Today, drones are being used with increasing frequency for military operations by a number of countries in combat, surveillance and reconnaissance roles. These machines tend to be larger than non-military drones and are, in the main, powered by jet or gas engines. Perhaps unsurprisingly, the use of drone technology has gained a measure of notoriety as a result of their growing prominence in military roles, which have been widely publicised in television, online and print media during the last decade and a half, leading to criticism of their application in this arena on both ethical and legal grounds.

C) While originally and currently still primarily used for military purposes, the rapid growth and development in drone technology during the early twenty-first century has led some experts to predict that, by 2020, there will be approximately 30,000 licensed drones operating in the skies above the United States alone. It has also been estimated that the economic value of the commercial drone market will rise in value to around $90 billion globally during the next five years, as well as create as many as 150,000 new jobs by 2025. A projection by the Association for Unmanned Vehicle Systems International estimates that agricultural applications will one day account for approximately 80 percent of commercial drone use.

D) One development related to the commercial use of drones which has perhaps received the greatest amount of news and media coverage in recent years is the establishment of Amazon Prime Air in December 2013 by the US-based online retail giant, Amazon.com. At this stage, Amazon Prime Air’s drone-based delivery system for its customers’ purchases remains very much a work in progress, although the company has been granted permission by the US Federal Aviation Authority (FAA) to begin testing its current prototypes under certain restrictions.

E) As far as aerial filming and photography are concerned, commercial drones have a number of applications in industries ranging from those of movie production and the news media, to real estate, telecommunications and security. More specific uses in these fields include, though are by no means limited to, taking promotional photos and videos for commercial and residential properties on the market, filming breaking-news stories and live sports events, producing footage from unique perspectives for movies and carrying out security and surveillance functions in the detection of criminal activity and identification of criminals.

F) In addition to the delivery of consumer products and other commercial applications, non-military drones are gaining popularity for use in search and rescue operations. Drone-mounted cameras enable unmanned aerial vehicles to follow pre-programmed search patterns when looking for missing persons and victims of natural disasters across a variety of otherwise inaccessible terrain types, including marine environments. With the addition of infrared thermal imaging camera technology, drones can also carry out search and rescue missions after dark, with much greater manoeuvrability and at less cost than using a helicopter, for example.

G) These days, drones are increasingly being used by national government agencies and local authorities for a variety of purposes outside of the private sector. Transport agencies, both road and rail, make use of unmanned aerial vehicles for monitoring traffic flow and reporting accidents and hazards, while civil planners utilise the technology to assist with mapping and surveying work. Fire departments in some jurisdictions now rely on UAVs to help them reduce risks and costs when fighting fires in both urban and rural areas, while customs and law enforcement agencies also employ drone technology in protecting citizens and borders through monitoring and surveillance.

H) In terms of the natural world, scientists and researchers are turning to drones with greater frequency to monitor, document and assess changes in the health, movement and distribution of flora and fauna, as well as pollution, weather and the climate, both conveniently and cost-effectively. Unmanned aircraft are today being used not only in environmental and ecological research, but also as cutting-edge tools to assist in wildlife conservation efforts. In the latter capacity, drone technology is now being used by both governmental agencies and non-governmental organisations in the surveillance and prevention of illegal hunting and poaching of a number of endangered species.

I) While advocates of drones are quick to point out all of the many benefits that the machines can bring to society and the planet, the technology is not without its critics. Those opposed to the growing use of unmanned aerial vehicles cite a number of negative aspects related to the seemingly inexorable rise of drones and their myriad possible applications in our lives. These include logistical concerns such as the comparatively short flight times of smaller UAVs (presently between 30 and 45 minutes) and their operational limitations in terms of spatial mobility. Other perceived disadvantages are safety risks, in the potential for collisions across increasingly crowded airspace, and even the adverse effects drones may have on the natural environment, particularly as contributors to noise pollution.

J) Whether for commercial or recreational applications or being used as tools to assist those working in the public sector, it would appear that the numerical proliferation of unmanned aerial vehicles, as well as their numerous potential uses, means that the impact of drone technology in our lives is only set to increase. While there are undoubtedly issues yet to be resolved regarding the use of drones, particularly in relation to regulatory oversight and legal restrictions on the part of relevant authorities, the futuristic technology afforded us in the form of these robotic vehicles indicates that not the sky, but rather the solar system and beyond, may be the limit.

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