Nevado del Ruiz 1985

The Colombian volcano Nevado del Ruiz is an active stratovolcano with a history of generating deadly volcanic mudflows (lahars) from relatively small-volume eruptions. In 1595, a lahar swept down the valleys of the River Guali and the River Lagunillas, killing 636 people. In 1845, an immense lahar flooded the upper valley of the River Lagunillas, killing over 1000 people. It continued for 70 kilometers downstream before spreading across a plain in the lower valley floor.
The young village of Armero was built directly on top of the 1845 mudflow deposit. Over the ensuing years, Armero grew into a vibrant town with over 27,000 residents. On November 13, 1985, history repeated itself for the third time in 400 years, with another eruption and another deadly lahar racing down the River Lagunillas. This time, over 23,000 people were killed, including most of the residents of Armero. With proper planning, this tragedy could have been averted. Click volcanic hazards map for more information.
Nevado del Ruiz is the northernmost of several Colombian stratovolcanoes in the Andes Volcanic Chain of western South America. The Andean volcanic belt is generated by the eastward subduction of the Nazca oceanic plate beneath the South American continental plate. Typically, such stratovolcanoes generate explosive Plinian eruptions with associated pyroclastic flows that can melt snow and glaciers near the summit, thus producing devastating lahars.

(section was taken from: http://www.geology.sdsu.edu/how_volcanoes_work/Nevado.html)

Tambora 1815

Tambora is on Sumbawa Island along the east Sunda Arc. It lies some 300 kilometers behind the Sunda Trench, but the subduction zone in that area has a shallow dip and is less than 200 kilometers deep beneath Tambora (Alzwar and others, 1981). Tambora is a large stratovolcano composed dominantly of nepheline-normative, leucite-bearing trachybasalt and trachyandesite.Before its eruption in 1815, Tambora might have been in repose for as much as 5,000 years.At least 6 months and probably about 3 years of increased steaming and small phreatic eruptions preceded the 1815 Tambora eruption, the largest in historical time.

section taken from: http://vulcan.wr.usgs.gov/Volcanoes/Indonesia/description_tambora_1815_eruption.html

This eruption was very large considering the fact that the explosion was heard from 1,400 km away. Now that's a big bang!

Unzen Japan, 1792

Unzen is located in the Shimabara Peninsula and is east of the city of Nagasaki. In 1792, collapse of the Mayu-yama lava dome created an avalanche and tsunami that killed an estimated 14,524 people. Most of the people were killed by the tsunami.

Unzen is well know for Japan's greatest volcanic disaster. In 1792, about a month after lava stopped erupting from the volcano, a landslide from nearby Mount Mayuyama swept through ancient Shimabara City, entered the sea, and generated a tsunami that struck nearby areas. More than 15,000 people were killed by the landslide and tsunami. The amphitheater-shaped scar of the landslide is still clearly visible on Mount Mayuyama just above the city.



Samples taken from: http://vulcan.wr.usgs.gov/Volcanoes/Japan/description_unzen.html

Mt. Laki 1783

The Laki eruption lasted eight months during which time about 14 cubic km of basaltic lava and some tephra were erupted. Haze from the eruption was reported from Iceland to Syria. In Iceland, the haze lead to the loss of most of the island's livestock (by eating fluorine contaminated grass), crop failure (by acid rain), and the death of one-quarter of the human residents (by famine). Ben Franklin noted the atmospheric effects of the eruption (Wood, 1992).
The climatic effects of the Laki eruption are impressive. In the eastern United States, the winter average temperature was 4.8 degrees C below the 225 year average. The estimate for the temperature decrease of the entire Northern Hemisphere is about 1 degree C. The top graph shows change in acidity in micro equivalents H+ per kg in the Greenland icecap. The bottom graph represents the winter temperature records in the eastern United States. From Sigurdsson (1982).

The Laki eruption illustrates that low energy, large volume, long duration basaltic eruptions can have climatic impacts greater than large volume explosive silica-rich eruptions. The sulfur contents of basaltic magmas are 10-100 times higher than silica-rich magmas (Palais and Sigurdsson, 1989).


(post taken from http://volcano.oregonstate.edu/education/gases/laki.html)

Mt. Etna Italy (1669)

On March 8 1669 Mount. Etna started to erupt it left 20,000 killed and left thousands homeless. Many people could have survived if they had fled but decided to stay with there doomed city. Mount Etna dominates the island of Sicily. Rising 11,000 feet above sea level in the northeast section of Sicily, it can be seen from just about every part of the 460-square-mile island.

When Etna began to rumble and belch gas on March 8, the residents nearby ignored the warning signs of a larger eruption. Three days later, the volcano began spewing out noxious fumes in large quantities. Approximately 3,000 people living on the slopes of the mountain died from asphyxiation.
At the time, the city of Catania had about 20,000 residents; most failed to flee the city immediately. Instead, Diego de Pappalardo, a resident of the city, led a team of 50 men to Mount Etna.

(sections taken from Day in History)

Mt Vesuvius

Mt. Vesuvius is arguably one of the most famous volcanoes of it's time. The eruption in the year 79 AD. buried the ancient Roman city of Pompeii. The city lay forgotten for 1600 years until it was found buried under layers of volcanic ash. The inhabitants were probably dead before the ash reached their ankles because of the ash which they inhaled.
when Pompeii was excavated the workers found that the bodies of the inhabitants were perfectly preserved in hardened volcanic ash. The now empty volcanic ash shell was then filled with plaster.
If you travel to Pompeii you can see the plaster casts of the bodies.

4000 people died in the disaster