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UNIT 5
DYNAMIC EARTH

Task 1. Read and memorize the following words:
cool - прохолодний dense – густий, щільний, компактний
descend – рухатися (вниз) ultimately – в кінцевому рахунку, у підсумку
Earth’s shell – земна кора rigid – твердий, нерухомий, стійкий
entire – цілий, весь margin – поле, край, шельф
grinding movement – рух зі скрипом deform - деформувати
plate – тектонічна плита tectonic - тектонічний
rate – швидкість, темп convective – конвекційна (система)
set in motion – приводити в рух concurrently - одночасно
slab – плита,пластина intermediate - проміжний

Task 2. Transcribe and translate the following proper names: Eurasian, Australian,
Antarctic, Caribbean, Nazca, Philippine, Arabian, Cocos, Scotia.

Task 3. Read the following text, translate it into Ukrainian. Pay special attention to
the pronunciation of the following words: lithosphere, lithospheric, centimetres, earthquakes,
volcanoes.

The Theory of Plate Tectonics
According to the plate tectonics model, Earth’s rigid outer shell (lithosphere) is broken
into numerous slabs called lithospheric plates which are in continual motion. Seven major
lithospheric plates are recognized. They are the North American, South American, Pacific,
African, Eurasian, Australian, and Antarctic plates. Intermediate size plates include the
Caribbean, Nazca, Philippine, Arabian, Cocos, and Scotia plates. Over a dozen smaller plates
have been identified as well. Note that several large plates include an entire continent plus a
large area of seafloor (for example, the South American plate). However, none of the plates is
defined entirely by the margins of a single continent. The lithospheric plates move relative to
each other at a very slow but continuous rate that averages about 5 cm a year. This movement is
ultimately driven by the unequal distribution of heat within Earth. Hot material found deep in the
mantle moves slowly upward and serves as one part of our planet’s internal convective system.
Concurrently, cooler, denser slabs of lithosphere descend back into the mantle, setting Earth’s
rigid outer shell in motion. Ultimately, the titanic, grinding movements of Earth’s lithospheric
plates generate earthquakes, create volcanoes, and deform large masses of rock into mountains.

Task 4. Answer the following questions, using the vocabulary from Task 1.
1. What is Earth’s rigid outer shell broken into?
2. Are plates in continual motion?
3. How many major lithospheric plates are there?
4. Name big size plates.
5. Name the intermediate size plates.
6. The plates are defined entirely by the margins of a single continent, aren’t they?
7. Do the lithospheric plates move relative to each other at a very slow or quick rate?
8. In what way does hot material found deep in the mantle move?
9. What generates earthquakes, create volcanoes, and deform large masses of rock into
mountains?
10. What does the Theory of Plate Tectonics state?

Task 5. Complete the following sentences from the text in Task 3.
1. Earth’s lithosphere is broken into … .