Text 6. Mayon volcano stirs back to life

Mayon, one of 22 active volcanoes in the Philippines, has a history of at least 47 violent eruptions. In its deadliest blast in 1814, the volcano killed 1,200 people as it buried a town under mud and rocks, leaving only the church steeple visible.

Mayon volcano in the Philippines blasted back to life, spewing out fiery rocks in an explosion that suggests more eruptions could be on the way. It erupted on Thursday, July 26, creating a column of ash 10 kilometres high and shooting lava 60 meters into the air.

About 40,000 people fled their villages after three blasts, which some witnesses described as being more violent than those that shook the area on June 24. No casualties were reported, but most residents chose to stay in evacuation centres around the provincial capital Legazpi, 11 kilometres from the crater. Schools in Legazpi and other communities outside the danger zone were converted into evacuation centres.

Scientists said the number of tremors continued to increase and that Mayon's emissions of sulphuric fumes remained at the high rate of 4,800 tons a day -- far above normal levels of 500 tons. The 2,460-metre (8,000-foot) volcano reminded observers of its awesome power in an explosion that left the local population pondering their immediate future.

Passenger jeeps kicked up volcanic ash, farmers rode water buffaloes to fields as residents wiped ash off their homes within the four-and-a-half-mile danger zone around Mayon.

Experts said that high sulphur-dioxide emissions and quakes indicated that Mayon could explode again and send clouds of ash and rock fragments down the slopes. Known as pyroclastic flows, the clouds can reach speeds of up to 60 miles an hour and temperatures of 1,300 degrees, incinerating anything in their path.

While volcanic activity had lessened since Thursday's eruption, areas around Mount Mayon were shrouded in grey ash on Friday and volcanic mud was beginning to harden. Due to ongoing tremors and significant ground deformation that were being detected experts expected more explosive activity in the following days.

Residents complained of eye irritations from the sulphur and dust-laced atmosphere.

There were great concerns that the crater wall might give way during the draining operations creating deadly flash-floods. However, with the water beginning to seep out along a specially dug channel on Friday, officials said they were confident it was safe enough for local residents to return and the greater majority of the evacuees were allowed to go home.

Government geologists and engineers began to drain the massive lake within Mount Pinatubo's crater following fears that annual monsoon rains from June to October would cause the lake to overflow. Before the operation began the water level was just a few meters below the lake's rim. Engineers planned to drain off a tenth of around 210 million cubic meters of lake water to decrease the pressure on the crater-wall. The water was being channeled through a 75-meter-long man-made canal on Pinatubo's slope, down to a flood plain, river tributaries, and westward to the South China Sea. The draining began Thursday but started as little more than a trickle because the channel had not been excavated at a sufficient angle. By the end of the day officials said further excavation had increased the outflow to 1,800 cubic meters per hour. There was no damage to people or property.

Scientists said on Monday that an estimated 50,000 villagers wishing to return to their homes around the mountain's base would have to reconsider, because clear visual conditions the previous night (Sunday) revealed forceful expulsion of incandescent lava fragments accompanied by jet-like roaring sounds. This means it was in state of hazardous eruption with significant potential to erupt more explosively.

Relief officials said they had allowed some evacuees to return to their homes because they lived in villages outside the designated danger zone more than seven km (four miles) from the volcano's summit.

"We have increased our watch on areas within the danger zone to prevent the others from also going back," chief provincial relief officer Cedric Daep said.

But experts in the Philippines were warning of more explosive activity. They were maintaining an alert level five on the 2,460-metre (8,000-foot) mountain - which meant a hazardous eruption was in progress - and kept areas within seven kilometres from Mayon’s crater a no-man's land.

Exercise 1. Read the following sentences and decide whether they are true (T) or false (F). Say why.

1) There are more than 25 active volcanoes in the Philippines.

2) The deadliest blast in 1814 killed about forty thousand people.

3) There were three blasts this time but no casualties were reported.

4) Schools in the neighbouring communities were converted into evacuation

centres.

5) Clouds of ash reached speeds up to 71 miles an hour.

6) Volcanic activity lessened by the end of the week.

7) Engineers planned to drain water into the lake in order to increase the

pressure on the crater-wall.

8) There were no possibilities of more explosive activity.

Exercise 2. Complete the following sentences with the correct form of the word.

1) When life in the damaged area returned to normal all __________ were allowed to

come back to their houses,

a) evacuate b) evacuation c) evacuees d) evacuated

2) Though there is too little place to dump rubbish nobody wants to have __________

near their house.

a) incinerate b) an incinerator

c) incineration d) incinerating

3) At high temperatures this gas is ____________.

a) explode b) explosion

c) explosively d) explosive

4) Yesterday astronomers could _____________ the opposition of the planets.

a) observe b) observer

c) observation d) observable

5) There are many terrorist ____________ reported in this country.

a) actors b) acts

c) actively d) activity

Exercise 3. Read the text and decide which answer A, B, C, or D best fits each space.