On the island of Sumbawa the eruption of Tambora between 5 an 12 April 1815 killed about 10,000 islanders immediately. A further 82,000 died later from disease and famine. This made it the worst- ever eruption for loss of human life.
Iceland is one of the most volcanically active places on Earth, but the population is small so eruptions seldom cause many deaths. On 11 June 1783 the largest lava flow ever recorded engulfed many villages in a river of lava up to 80 km long and 30m deep. it released poisonous gases that killed those who managed to escape the lava flow – up to 20,000 people.
Cherrapunji, Assam, India, 26,461 mm between 1 August 1860 and 31 July 1861 – Which is close to the length of a tennis court! Also, at the same place, the greatest in one calendar month – 9,300 mm – fell in July 1861. That’s about the same as five people standing on each other’s heads.
31,102 mm at Mt Rainer, Washington, USA, from 19 February 1971 to 18 February 1972. This is an incredible 31 m, equivalent to 17 people standing on each other’s heads!
Atacama Desert, Chile, where average annual rainfall is officially nil (also longest drought – 400 years up to 1971). The average rainfall on the Pacific coast of Chile between Arica and Antofagasta is less than 1 mm (0.01 in).
The fastest sustained winds in a hurricane in the USA measured 322 km/h, with 338 km/h gusts, on 17-18 August 1969, when Hurricane Camille hit the Mississippi/Alabama coast.
Commonwealth Bay, Antarctica, has some consistently high wind speeds, occasionally reaching 320 km/h. The highest individual gust of wind measured was 371 km/h at Mt Washington, USA on 12th April 1934.
Galileo invented the thermsocope, a form of thermometer. Later, sealed thermometers using mercury, which expands in a narrow tube as the temperature rises, were developed. Gabriel Fahrenheit’s scale dates from 1714, and that of Anders Celsius from 1742. The maximum and minimum thermometer, which records the highest and lowest temperatures reached over a period of time, was invented by James Six a Cambridge in 1780.
Rain gauges – containers that measure the amount of rain that has fallen – date from ancient China and India. In 1662, British architect Sir Christopher wren invented a tipping bucket rain gauge, which emptied itself when full.
Wind speed is measured by a cup anemometer. This has three or four cups that rotate round a vertical rod. The speed at which the wind spins the cups round is recorded by a counter. A Wind vane shows the direction of wind, and an anemograph records the speed on a chart.
Weather forecasters use a range of instruments. Balloons, radar stations and orbiting satellites also provide increasingly accurate weather information, and computer programs are able to make detailed forecasts.
Tornados, or twisters, are columns of air that spin violently, reaching speeds of over 420 km/h. They destroy crops and any houses or vehicles in their path. Tornadoes are rare in the UK, but one struck Kensel Rise, London, on 7 December 2006, damaging houses and cars. In the book and film of The Wizard of Oz (1939) Dorothy is carried by a tornado from her Kansas home to the magical land of Oz.
The hottest place where people live is Djibouti, in the Republic of Djibouti, Africa. The average temperature is 30 o C. Next hottest are Timbuktu in Mali and Tirunelveli in India, both 29.3 o C. The coldest place where people live in Norilsk, Russia, with an average temperature of –10.9 o C. Next coldest is Yakutsk in Rusiia, at -10.1 o C.
There are ten types of clouds. Each has a characteristic shape and appears at certain levels in the sky. Altocumulus 2,000-7,000 m Cirrocumulus 5,000-13,500 m Cirrus 5,000-13,500 m Cirrostratus 5,000-13,500 m Altostratus 2,000-7,000 m Nimbostratus 900-3,000 m Cumulus 450-2,000 m Stratocumulus 450-2,000 m Cumulonimbus 450-2,000 m Stratus below 450 m
The Beaufort scale was introduced in 1806 by British Admiral Sir Francis Beaufort (1774- 1857) to describe wind effects on a fully rigged man-of-war ship. It was later extended to describe how winds affect land features such as trees. The Beaufort scale is divided into values from 0 for calm winds to 12 and above for hurricanes. Forecasters often describe winds by their force number – for example, a force 10 gale. Wind speed can also be measured in knots: 1knot = 1.85 km/h. 0 Calm : 0-2 km/h 1 Light air : 3-6km/h 2 Slight breeze : 7-11 km/h 3 Gentle breeze : 12-19 km/h 4 Moderate breeze : 20-28 km/h 5 Fresh breeze : 29-38 km/h 6 Strong breeze : 39-49 km/h 7 High wind : 50-61 km/h 8 Gale : 62-74 km/h 9 Strong gale : 75-88 km/h 10 Whole gale : 89-102 km/h 11 Storm : 103-117 km/h 12 Hurricane: 118 km/h +
True deserts are very hot – 40 o C or more – during the day, but cold at night. They are very dry and what little rain there is falls is short sudden bursts and evaporates quickly. Few plants can grow in deserts but some animals manage to survive.
These areas are hot all year round. In some parts there is heavy rain all year round too, and that is where rainforest grow. Rainforest plants fruit and flower all year. In other tropical areas, such as savannas and scrubland, there are dry seasons and rainy seasons, when most of the year’s rain falls.
The climates of mountain areas vary according to altitude. The higher the mountain, the colder it is. At a certain point, called the tree line, trees can no longer grow. The climate in mountain areas is usually wetter than in the lowlands around them
