The explosion of Mount Tambora, 1815

The explosion of Mount Tambora, a volcano, in April 1815 is generally regarded as the largest explosion ever recorded. Not only did it kill thousands of people, but it also had lasting effects on a worldwide scale.

Before the explosion, Mount Tambora rose to 13,500 feet on the Indonesian island of Sumbawa. However, after the mountain blew itself apart it would be 4,500 feet shorter. This happened after three huge columns of fire rose from the volcano’s crater followed by the explosion which has been estimated as having had the power of 60,000 Hiroshima-type atom bombs. The blast could be heard up to 1,000 miles away.

The eruption of the volcano lasted for two days, during which time some twelve cubic miles of ash were pumped skywards. This was more than double the amount that would be ejected by the more famous eruption of Krakatoa 68 years later.

When the ash fell to earth it covered the area nearest the volcano to a depth of 90 feet. The area of land and sea that received at least half an inch of ash was around 200,000 square miles, which was roughly the size of France. This coverage was enough to destroy growing crops and lead to mass starvation. Around 12,000 people were killed by the original explosion but another 50,000 died as a result of crop failures caused by the ash.

Much of the ash was sent so high into the atmosphere that it was taken right round the world by air currents moving at high latitudes. This had the effect of dimming the sun and causing spectacular sunsets with brilliant orange and red colours. These were featured in a number of paintings produced by the famous British artist J M W Turner.

The following year was known in northern latitudes as the “year without a summer”, due to the disruption of weather cycles caused by the ash cloud. The temperatures were abnormally low and in parts of Europe the rainfall was up to three times what it should have been. This led to disastrous harvests and agricultural distress, and must count as an important factor in the rise of radical protests and riots in the period up to 1820.

The 1815 eruption was followed by smaller Tambora eruptions in 1819, 1880 and 1967. Could the monster roar again at some time in the future? Maybe!

© John Welford