Vulcanoes have caused the death of about 280,000 humans since 1500 - 170,000 of them through only six explosions. Since 2000, about 2,000 persons have been murdered. There are currently about 800 million inhabitants living within 100 km of an energetic vulcano - a long way from potentially fatal orbits.
"Actively " does not mean that all these volcanos are breaking out, but that we believe that they have been activated recently and are able to erupt again. Volcanos represent many different kinds of dangers for those who are living near them. From then on, some 5 km of water flowed down to the sea, destroyed houses and evacuated tens of millions of people.
Lavastreams like that don't slay a lot of humans. As they burn and bury everything in their way, the melted rocks - which glow at a temperature of about 1200 degrees Celsius - move slow enough that humans can usually just go away. Hazard occurs when humans do not quickly move away. Several persons were brought to Hawaii after their emergency exits were slashed.
The lava can cause an explosion, which includes the combustion of metane from burying the plants. A further danger in Hawaii is sulfur oxide, one of several gasses that can be emitted by volcanos, even if they do not erupt. In Cameroon in 1986, the biggest casualty of vulcanic acid was when more than 1,500 lives were lost when CO2 from Lake Nyos was flowing into the area.
The majority of those murdered by volcanos are casualties of fireworks and lahar - vulcanic mudslides that have caused some 120,000 fatalities in the last 500 years. The avalanche is a very rapid avalanche of rocks, coal and gases, which can rise to a temperature of up to 700°C.
In 79 AD, Pompeii was ruined by a series of Pyroklastic rivers. It forms as precipitation, snows or fusing ices and washes away at high speed from the volcanoes' hillsides and into the nearby valley. During large explosions, volcano flyovers can cover several hundred or even thousand kilometers.
But although inexorable, volcanoes do not have to lead to catastrophe and deaths. Unfortunately, due to scarce natural resource base, few volcanos worldwide are as well controlled as Kilauea. Satelite surveillance allows even the remotest volcanos to be observed, but only about 20% of the world's volcanos have ground-based surveillance.
They can be the most hazardous, as long rest phases can result in more explosives and those nearest to them are least cautious. It would be a good idea to observe the volcanos of the earth even if they seemed to be asleep.