One of the deadliest natural disasters to occur throughout recorded history is a volcanic eruption. The destructive effects include death tolls that reach tens of thousands, entire inhabited areas wiped out, climatological changes and, at times, permanent geographical or topographical alteration.

History has recorded a lot of major volcanic eruptions, but details such as the death toll can only be estimated or hypothesized. Other major eruptions are lacking in documentation.

For instance, the eruption of Santorini in Greece in 1650 BC is assumed to have wiped out an entire civilization. Scientists also believed that another eruption somewhere in the Near East around 70,000 years ago caused a major volcanic holocaust.

Below are the the seven of the most destructive volcanic eruptions, in terms of human casualties, over the last 2,000 years:

Mount Vesuvius (Italy), 24-25 August 79 - In one of the most famous volcanic eruptions in history, the Roman towns of Pompeii and Herculaneum were buried up to ten feet of volcanic ash, killing perhaps more than 10,000 people.

Pyroclastic flows burned and asphyxiated many, and today around 1,500 remains of bodies (specifically, ash-surrounded casts which formed over their disintegrated bodies) have been discovered. Many remains have incomplete heads, since it is believed that many victims' brains exploded from the intense thermal pressure.

Mount Etna (Italy), 25 March 1669 - Preceded by a series of earthquakes, the fiery Sicilian mountain spewed over 800 million cubic meters of lava, destroying several villages and partially obliterating the city of Catania. 20,000 people are believed to have perished over a span of two months, despite efforts by the inhabitants to divert the lava flows.

Mount Unzen (Japan), 21 May 1792 - Considered as the Japan's worst volcanic disaster, up to 15,000 people are believed to have perished after an earthquake caused one of the volcano's lava domes to collapse, triggering a massive avalanche and a tsunami that battered the island of Kyushu.

Mount Tambora (Indonesia), 5 - 15 April 1815 - This eruption is the largest observed eruption in recorded history, killing an estimated 72,000 people, and creating abrupt climate changes that were felt around the globe.

The 13,000 feet-tall volcano was reduced to 9,000 feet after it ejected over 93 cubic miles of sulfuric debris into the stratosphere, resulting in climatological anomalies that were observed up to the next year.

Average global temperatures went down to about 0.4-0.7 degrees Celsius, resulting in agricultural disasters in the western hemisphere. In various areas of the United States, dry fogs, out-of-season frost and snowing occurred; as a result, 1816 was known as the "Year Without A Summer."

It is also believed that up to 100,000 people perished due to ensuing crop failures and famines which was considered as the 19th century's worst.

Mount Krakatoa (Indonesia), 26-27 August 1883 - This famous eruption ejected more than 25 cubic kilometres of rock, ash, and pumice, with the explosion generating the loudest sound in recorded history.

It was heard as far as 1,930 miles away in Perth, Australia and 3,000 miles away in the island of Rodrigues near Mauritius. Over 36,000 people perished from the eruption and also from massive tsunamis (some reaching 100 feet high) that followed.

In the year following the eruption, average global temperatures fell by as much as 1.2 degrees Celsius, resulting in erratic weather patterns that persisted up to 1888. It is even believed that the hauntingly red sky in Edvard Munch's famous 1893 painting The Scream depicts a post-eruption, climate-affected sky seen in Europe in 1883.

Mount Pelée (Martinique), 8 May 1902 - Regarded as the most disastrous volcanic eruption of the 20th century, the massive pyroclastic flow of hot gas, rock and ash obliterated the town of Saint-Pierre in a matter of hours and killing the town's entire population of around 30,000, except for three individuals: a convict held in an underground cell, a shoemaker, and a little girl.

The catastrophe redefined the science of volcanic eruptions, with volcanologists analyzing the way Pelee exploded. Today the term "Pelean Eruption" is used in eruptions that feature avalanche-type pyroclastic flows and the formation of lava domes.

Mount Nevado del Ruiz (Colombia), 13 November 1985 - Despite its being a small eruption, the ensuing pyroclastic flows melted the volcano's ice cap, creating monstrous 50-meter thick lahar flows that cascaded down several river valleys, destroying the town of Armero and killing up to 23,000 inhabitants.

Many survivors also died of ash-induced bacterial infections that were found to be antibiotic-resistant. This is regarded as the worst volcanic disaster of the 20th century after the 1902 eruption of Mount Pelée.