Today we will learn some words connected with volcanoes; and we will find out that volcanoes are bad for aeroplanes, and why people in west London can now hear the birds sing.
Volcanoes are mountains, or other places, where the inside of the earth comes to the surface. Volcanoes sometimes throw a large amount of hot gas and ash high into the atmosphere, or they spill very hot melted rock, called lava, over the land. We call events like these “eruptions” and we can say that a volcano “erupts”. An active volcano is a volcano that erupts from time to time, like Mount Etna in Italy. An extinct volcano is one which does not erupt any more, like Kilimanjaro in Africa. And a dormant volcano is, well, just sleeping and might wake some time and erupt again.
There are several active volcanoes in Iceland, and last week one of them erupted. It sent a huge cloud of gas and ash into the air. The ash has drifted south-east-wards towards Britain and the rest of Europe and for the last several days, there has been a cloud of volcanic ash over most of north-west Europe. We cannot see it from the ground, but it is visible on satellite pictures.
If an aeroplane flies through a cloud of volcanic ash, the engines may suck the ash in. The ash may then cause corrosion and abrasion. (“Corrosion” is when the ash reacts chemically with the steel and other materials in the engine; “abrasion” is when the ash scratches and wears the surface). Aircraft engines are very hot, and they may melt the volcanic ash into a material like glass. So, altogether, volcanic ash is bad news for aircraft engines. In the 1980s there were some frightening cases where an aeroplane flew through a cloud of volcanic ash, and all the engines stopped working.
At the end of last week, therefore, the air-traffic control authorities in Britain and other European countries decided that it was not safe to let aeroplanes fly through the volcanic ash.
The airlines which normally fly businessmen to meetings in New York or Hong Kong, or holidaymakers to sunny places in the Mediterranean, have stopped flying. They have cancelled all their flights. To cancel something means to decide that it will not happen. An airline might cancel a flight; a railway company might cancel a train. Recently the lead singer in Kevin’s favourite group, Futile Vendetta, had a sore throat – poor man! – and the band had to cancel two concerts.
Because all flights in and out of Britain have been cancelled, people who were visiting Britain as tourists or on business are stranded. And many British people who are away from home are stranded as well. If you are “stranded” it means that you cannot leave somewhere. If you miss the last bus home, you may be stranded until the next morning. If you run out of money while you are on holiday, you may be stranded. Other words which mean almost the same as “stranded” are “stuck”, “trapped” and “marooned”. There are no flights and I am stuck in Berlin. I have lost my money and my passport and I am trapped in Greece. I arrived at the airport too late and now I am marooned in Spain.
The volcano in Iceland is still erupting, and the cloud of volcanic ash shows no signs of clearing. No-one knows when it will be safe to fly aeroplanes again. Life without air travel is a bigger problem for Britain than for other countries because Britain is an island and you cannot simply drive your car over the border into a neighbouring country. All the ferries and the Eurostar train service are fully booked with people trying to get home.