Eruption of Tambora in 1815

Events

On April 5, 1815, a first eruption occurred, giving an eruptive column of 33 km height and which lasted 33 h . People did not leave their house. During the following days, the volcano remained in a state of low activity. On the 6th of April, a slight fall of ashes made it clear to the inhabitants of Batavia ( Jakarta today, at 1 260 km from the volcano) that the detonations heard the previous day which had motivated the sending of military patrols for fear of an attack, were of volcanic origin.

The paroxysm of the eruption took place five days later, on April 10th. Around 10:00 am , a 44- kilometer eruptive column rose in the sky, but the eruption lasted only three hours. Around 7 pm , the activity of the volcano increased, followed one hour later by a rain of pumice on the village of Sanggar, 30 km to the east. The volcano at that moment was then surmounted according to the witnesses of three “columns of flames”, in fact three eruptive columns. The falling of pumice stones lasted until 22 hwhen the village of Sanggar was ravaged by a shock wave. About this time, according to the witnesses, the three columns merged and the mountain was no more than a mass of “liquid fire”. This corresponds to the widening of the emission duct due to the important eruptive flow and the early stages of the formation of the caldera. As a result, the eruptive column engulfed in matter and eventually collapsed, creating several pyroclastic flows of overheated gas, ash and pumice that gave rise to deposits of ignimbrite . Seven were spread radially around the volcano and penetrated into the sea up to 40 kmfrom the top of the volcano. These pyroclastic flows launched into the sea generated secondary explosions, increasing the volume of ash dispersed in the atmosphere to represent the main source of volcanic ash from the eruption. On April 12, when the eruption continued, the eruptive umbrella had spread to the point that at 900 km away in Java, while the explosions resounded in the distance, the first light of day appeared only 10 h and it was not until 11 o’clock that the birds began to sing. The eruption stopped only on April 15, and on April 17 only the ash falls ceased after spreading away, leaving a devastated landscape on the Sanggar Peninsula.

This is the most powerful eruption referenced in historical times ² . It had a power estimated at 6 times that of the eruption of Mount Somma (ancestor of Vesuvius exploded at the time of Pompei) , the equivalent of 20 000 bombs of Hiroshima. The explosions of the volcano were heard more than 1,400 km away.

Following the expulsion of magma as the rest of the mountain collapsed on itself, and formed a large caldera of 6 km in diameter and 1 km deep, reducing the height of the volcano 1,400 meters .

The tidal wave descended upon the islands several hundred kilometers away. Volcanic activity directly killed 11,000 people . To these victims were added tsunamis, famine and epidemics that plagued Sumbawa and Lombok and killed 49,000 people . In total, the eruption seems to have killed between 61 000 and 71 000 ³ .

This eruption is rated at 7 on the volcanic explosive scale of 8.

Climate consequences

The ashes sent into the stratosphere circled the Earth several times, causing, at the beginning of summer, beautiful glowing sunsets, painted by the painter William Turner : see notably Didon building Carthage (or the birth of the Carthaginian Empire) , 1815, National Gallery , London.

This eruption was the most violent volcanic eruption ever known historically, and especially the most deadly. It was much stronger than that of Vesuvius and yet much less famous, not to say unknown. Indeed, at this time, Europeis witnessing political events of great importance: the Hundred Days episode , the Battle of Waterloo and the fall of Napoleon , and the partition of Europe at the Vienna Congress .

The amount of material emitted was 150 km ³ , it was much larger than for Krakatoa and Vesuvius .

This catastrophe was at the origin of a general cooling of the climate and “frozen summers”. The year 1816 in particular remained known as the ” year without summer ” ^4 , 5 : the eruption has indeed affected oceans and tropics, and all records of temperature drop were beaten in 1815 and 1816. In 1816 , average temperatures in the northern hemisphere down to 0.5 ° C over 1 ° C .

In the United States , the states of the East Coast were particularly affected ( Maine , New England , Massachusetts ). In Europe , the Swiss Alps were very affected, so much so that in the summer of 1816 there was snow almost every week. The Alsace also enjoyed great food difficulties.

It is estimated that this climate change was the cause of a famine that claimed more than 200,000 lives worldwide.

The suites on site

Volcanologist Haraldur Sigurðsson has thoroughly studied this eruption for more than 20 years.

During a difficult expedition, he descended into the caldera of the volcano. The descent to the vertical took half a day.

On the old site of the village, using scanners, he was able to find remains of houses and charred skeletons buried in the ashes .

Current Research

Today, research on this eruption is of great importance because it helps to distinguish between natural and man-made climate change.

Many testimonials of climate change have been made by different people. Michael Chenoweth studied the logbooks of the British navy at the time, and those of the ship’s captain L’inconstant who made very accurate readings. US President Thomas Jefferson has accurately observed all of these climate changes.

Notes and references