Vocabulary:

natural disasters – природні катаклізми tornado – торнадо

volcanic eruption – виверження вулкану earthquake – землетрус

flood – повінь avalanche – лавина

drought – посуха famine – голод

forest fire – лісова пожежа hurricane – ураган

I. Answer the questions:

1. Which natural disasters occur in Ukraine? How often?

2. What type of natural disaster is the scariest to you? Why?

3. What is the worst natural disaster that you can remember?

4. What do you think is worse – natural disasters or manmade disasters?

II. Group up the words in the box according to the columns below.

Tsunamis, droughts, blizzards, avalanches, tornadoes, hurricanes, floods, earthquakes, hailstorms, heat waves, landslides, fires, ice storms, volcanic eruptions, tornadoes.

Land movement disasters	Water disasters	Weather disasters

III. Match natural disasters in the box with their descriptions below:

Earthquake, floods, tsunami, tornado, volcanic eruption, hurricane, forest fire, drought, avalanche.

... are the result of prolonged rainfall or rapid melting of large amounts of snow.

... is a slide of a large snow mass down a mountainside.

… is a violent, rotating column of air, which can blow at speeds between 48 and 50 km/h.

... is defined as a shortage of water and crop failure. It is an abnormally dry period.

… is an uncontrolled fire burning in wildland areas. It can be caused by lightning or drought.

… is a sudden occurrence of a violent discharge of steam, molten rock and ash.

… is a sudden movement of the earth's crust.

… is a large, often destructive, sea wave produced by an underwater earthquake or volcanic eruption.

… is a severe, often destructive storm.

Topic 20. Earthquakes

Earthquakes

An earthquake occurs due to underground activity such as the movement of tectonic plates. The location where the earthquake starts is called “hypocenter” (or “focus”). The location above it is called “epicentre”. The epicentre is the point on the surface where the earthquake is the strongest.

The Richter scale is the system of measurement of earthquakes. The largest earthquake in history occurred in Chile in 1960 (9.5). The second most powerful earthquake in history occurred in 2004 in the Indian Ocean. Although the earthquake itself caused little damage, the tsunami that happened after it did much harm and killed thousands of people. An earthquake of less than 2.0 on the Richter scale is known as a microearthquake and is not felt. There are approximately 8,000 microearthquakes every day!

What causes an earthquake?

• There are about 20 plates along the surface of the earth that move continuously and slowly past each other. The plates usually move at about the same speed that your fingernails grow. Earthquakes usually occur where two tectonic plates meet.

• Volcanic eruptions, rockfalls, landslides, and explosions can also cause an earthquake.

• Nuclear explosions under the ground can create waves that are very similar to natural seismic waves.

Where do earthquakes occur?

Earthquakes can strike any location at any time. But history shows they occur at the same time year after year, principally in three large zones of the earth. 

The most important earthquake belts are:

• The Circum-Pacific Belt, which affects many regions around the Pacific Ocean (New Zealand, New Guinea, Japan, Alaska, and the western coasts of North and South America). This belt got the nickname "Ring of Fire". 

• The second important belt, the Alpide, extends from Java to Sumatra through the Himalayas, the Mediterranean, and out into the Atlantic.

• The Mid-Atlantic Ridge is the third most important earthquake belt. 

Classification of earthquakes

The Richter scale is used to measure the amount of energy released by the earthquake. The severity of an earthquake runs from 0 to 10 on this scale.

• Slight Magnitude up to 4.9 on the Richter scale.

• Moderate Magnitude 5.0 to 5.9

• Strong Magnitude 6.0 to 6.9

• Major Magnitude 7.0 to 7.9

• Great Magnitude 8.0 to 9.9

• Violent Magnitude 10.0 and more

The study of earthquakes is called seismology. The earthquake causes seismic waves, which can be recorded on a sensitive instrument called a seismograph.

Damage Caused by Earthquakes

1. Earthquake can cause massive damage and destruction. Earthquake strikes suddenly, violently, and without warning at any time of the day or night. It may cause many deaths and injuries. It may also damage property.

2. The earthquake ruins buildings and breaks water and gas lines.

3. It can also start uncontrollable fires.

4. An earthquake can cause mud slides, which move down mountain slopes and bury everyting below.

5. An underwater earthquake can cause a tsunami.