There are several different types of volcanic eruptions, categorized by the magnitude of the eruption and the geological characteristics of the volcano and the event. A Plinian eruption is the most destructive type of volcanic event. One Plinian volcano -- Vesuvius -- buried the ancient Roman towns of Pompeii and Herculaneum in A.D. 79. A Plinian eruption can last for days and shoot solid volcanic material (pyroclastic rocks) as high as 30 miles (48 kilometers) into the air. It spews consistently, creating a sustained eruption plume that spreads a significant amount of tephra (fallen volcanic material) on the area all around the volcano. While the hot, toxic gasses and falling ash are probably the most dangerous elements of a Plinian volcanic event, such an eruption can also create a swift lava stream capable of causing a huge amount of destruction on its own. Compare this to a Hawaiian eruption, which may produce "fire fountains" and lava pools, but in which nearly all lava is slow-moving and less dangerous.
Plinian eruptions in the recent past, such as the 1980 eruption of Mount St. Helens, have caused great damage and loss of life, but even more destructive were the eruptions that occurred before humans had any understanding of geological science (meaning they had no good way to predict the eruptions). We can get some sense of the damage caused by an ancient Plinian eruption by observing the remains of the townships affected by the A.D. 79 eruption of Vesuvius. Herculaneum is situated near modern-day Naples. Herculaneum was an ancient Roman city where many rich Romans owned holiday villas. In 63 A.D. the city suffered severe damage from an earthquake. Whatever was left of Herculaneum was covered in ash, pumice and deep mud flows in when Vesuvius erupted. Many believed that the city had been abandoned before the volcanic eruption. However, excavations that began in 1738, and continued intermittently until the 1980s, unearthed more than 100 skeletons of people who were caught in passageways or were trying to flee by boat. Archaeologists also have uncovered a wealth of objects from the city, including a magnificent marble theater.
What kinds of severe earthquakes have hit Central Asia?
Answered by Planet Green
What's one criticism against an increase in hurricane intensity?
Answered by HowStuffWorks
Are there any specific times when hurricanes are most common?
Answered by Discovery Channel