1. Ответьте на следующие вопросы по тексту:

   1. What is igneous activity impossible without?

   2. What phenomenon is essential to clarify?

   3. What is the exact depth of magma formation?

   4. What principle can be applied to the modern volcanoes?

   5. What weight is necessary to push the magma up to the top of a 2,000-foot cone?

   6. What weight is necessary to push the magma up to the top of a 20,000-foot volcano?

   7. What is another big predicament?

   8. How can the relationship between pressure and melting temperature be expressed?

   9. Where does the temperature increase according to the measurements?

   10. What is the thermal gradient?

   11. What is the temperature increase rate?

   12. Does the gradient actually increase at this constant rate?

2. Найдите в тексте предложения, содержащие словосочетания из комментариев и переведите их письменно. Составьте свои предложения с этими словосочетаниями.

3. Раскройте скобки, употребив глаголы в нужном времени. Объясните ваш выбор временной формы:

1. Without magma igneous activity (to be) impossible.

2. The evidence (to show) the absence of molten rock extensive zones within 1,800 miles of the earth surface.

3. The exact depth of magma formation (to be not) known.

4. The liquid (to rise) to heights comparable to the pressure which (to apply) to it.

5. It is necessary for rocks (to melt) to form magma.

6. The melting temperature (to grow) higher as pressure increases.

7. This increase rate called the thermal gradient (to seem) to be around 30°C per kilometer of depth or 150°F per mile.

8. If the thermal gradient (to increase) at this constant rate, temperature at certain depths (to surpass) the melting range of all known rocks.

4. Дайте определение следующих слов и словосочетаний:

existing evidence

extensive zones

localized masses

current volcanoes

adequate amount of pressure

2.000 foot cone

predicament

further speculation

melting range

igneous activity

5. Раскройте скобки, употребив глаголы в нужном времени. Объясните ваш выбор временной формы:

1. It is not essential to clarify the formation of magma localized masses.

2. Old volcanoes supply us with indication about the depth which magma is coming from.

3. It would require 5 to 10 miles of rock weight to push magma up to the top of a 20.000-foot volcano.

4. The melting temperature becomes lower as pressure increases.

5. It is not necessary to search for another source of heat which causes igneous activity.

6. Объясните, в чем состоит проблема определения особенностей формирования магмы. Что вы можете сказать о следующих ситуациях:

1. the exact depth of magma formation

2. the source of a substantial quantity of heat

3. the temperature gradient increase rate in suppositions and in real life

TEXT 6.2.

VOCABULARY WORK:

• Запомните следующие слова:

Научный вокабуляр:

carbon dioxide [‚kRbqn'daIOksaId] - углекислота, углекислый газ

carbon monoxide [mq'nOk‚saId] - оксид углерода

sulphur ['sAlfq] gases ['gxsIz] - сернистый газы

hydrogen ['haIdrqGqn] - водород

hydrocarbon [‚haIdrqu'kRbqn] - углеводород

hydrogen sulphide ['sAlfaId] - сероводород

oxides ['OksaIdz] of sulphur ['sAlfq] - окись серы

ammonia [q'mqunIq] - аммиак

hydrochloric acid [‚haIdrq‚klOrIk'xsId] - соляная кислота

hydrofluoric ['haIdrquflH'OrIk] acid ['xsId] - фтористоводородная кислота, плавиковая кислота

opal ['qupl] - опал

chalcedony [kxl'sedqnI] - халцедон

geode ['GJqud] - жеода (минеральный агрегат, образовавшийся в результате заполнения пустот в горных породах)

Общеязыковой вокабуляр:

opening ['qupenIN] - отверстие

ash [xS] - зола, пепел

eject [I'Gekt] - извергать, выбрасывать, выталкивать (пары, пламя, дым)

ultimately ['AltImqtlI] - в итоге, в конце концов

particularly [pq'tIkjulqlI] - детально, подробно

volatile ['vOlq‚taIl] - летучее вещество

vapour ['veIpq] - пар; пары; испарения

evaporate [I'vxpq‚reIt] - испарять, превращать в пар

steam [stJm] - пар, дым

straightforwardly [‚streIt'fLwqdlI] - прямо, открыто

odour ['qudq] - запах

minor ['maInq] - незначительный, несущественный, второстепенный

ordinary ['LdnqrI] - обычный, ординарный; простой

release [rI'lJs] - отпускать, выпускать

porous ['pLrqs] - пористый, ноздреватый; губчатый

emanation [‚emq'neISn] - эманация, испускание

escape [I'skeIp] - улетучиваться, давать утечку

major ['meIGq] - более важный, значительный

assess [q'ses] - оценивать, определять величину

eruption [I'rApSn] - извержение analogy [q'nxlqGI] - сходство

research [rI'sE:C] - (научное) исследование

dissolve [dI'zOlv] - растворять; разжижать, разлагаться

illustrate ['Ilq‚streIt] - иллюстрировать

behaviour [bI'heIvjq] - образ действий, поведение

suppose [sq'pquz] - допускать, полагать, предполагать

erupt [I'rApt] - извергать

confine [kqn'faIn] - ограничивать

reduce [rI'djHs] - сокращать, уменьшать

viscosity [vIs'kOsqtI] - вязкость

distinguish [dI'stINgwIS] - различить

bottom ['bOtqm] - низ, нижняя часть

fill [fIl] - наполнять

fluid ['flHId] - текучая среда (жидкость, газ)

filling ['fIlIN] - наполнение

enthusiastically [In‚TjHzI'xstIklI] - с энтузиазмом

hunt [hAnt] - охотиться, разыскивать

• Прочтите следующий текст и переведите его:

Volcanoes

Volcano is an opening in the earth’s crust from which molten lava, rock fragments, ashes, dust, and gases are ejected from below the earth’s surface. The volcanoes study helps to find out a good deal about igneous processes. They are, ultimately, the single direct evidence for the magma existence in the earth crust.

There are several active volcanoes nowadays, for example Apo in the Philippines, Cameroon on the West African coast, Cotopaxi in central Ecuador, in the Andes, Etna in Eastern Sicily, Flores in Indonesia, Mauna Loa in Hawaii, New Britain in the South Pacific, Stromboli in the Lipari Islands off the North coast of Sicily, Taal in the Philippines and others.

There are several different types of active volcanoes and their differences depend on their magmas composition, more particularly on the behaviour of the magmas volatiles, that is substances capable of readily changing from a solid or liquid form to a vapour; having a high vapour pressure and a low boiling point. The magma main volatile is water which evaporates from volcanoes in the form of steam. The common volcanic gas is carbon dioxide but it is the sulphur gases (hydrogen sulphide and the oxides of sulphur) that are most straightforwardly noted near volcanoes because of their strong odours. Besides, minor amounts of such gases as ammonia, hydrogen, carbon monoxide, hydrochloric and hydrofluoric acid and hydrocarbons are released. Ordinary air, too, escapes from some volcanoes, in particular, those having porous rocks. Volcanic emanations are believed to have played a major role in the formation of the oceans and the atmosphere. Active volcano’s recent eruptions at Hawaii are assessed to have released one to two per cent gas concurrently with the eruption early stages and about one-half per cent during later stages. Laboratory research suggests that at depth magmas may contain up to five per cent dissolved water.

A simple analogy comes when illustrating water and other gases behaviour in volcanic magma. For the most part magmas are supposed to contain at least a few per cent water in solution. Being under considerable pressure due to the overlying rocks weight, most magma is able to dissolve this water. When magma is erupted to the surface the confining pressure is reduced and the gas is released.

In case magma has a low viscosity the gas simply escapes or forms bubbles in the resulting rock. The tops of lava flows can ordinarily be distinguished from the bottoms by the bubbles presence at the top. In some cases the bubble holes are filled with material deposited by the fluids or they can get filled later. Silica materials such as opal or chalcedony usually serve as fillings but many other minerals also occur here. Large filled holes of this kind are called geodes or thunder eggs and are enthusiastically hunted after by rock collectors who cut and polish them.

Комментарии к тексту:

molten ['mqultqn] lava - расплавленная лава

rock fragments ['frqgmqnts] - обломки породы

single ['sINgl] direct [dI'rekt] evidence ['evIdqns] - единственное прямое доказательство

active ['xktIv] volcano - действующий вулкан

readily ['redIlI] changing ['CeInGIN] from - легко меняться из

capable [keIpqbl] of a solid or liquid ['lIkwId] form - способный (находиться) в твердой или жидкой форме

boiling ['bOIlIN] point [pOInt] - точка кипения

are believed [bI'lJvd] - как полагают

concurrently [kqn'kArqntlI] with - одновременно с

overlying [quvq'laIN] rocks - покрывающие породы

bubble holes [hqulz] - отверстия, заполненные пузырьками (газа)

rock collector [kq'lektq] - коллекционер камней

READING COMPREHENSION