Active volcanoes are dangerous for a number of reasons, including their tendency to erupt and send poisonous gas and choking ash across wide areas. Even when they aren't erupting, volcanoes can potentially cause major landslides and sudden mudflows.Know More
Volcanic hazards can be grouped into three categories: ejecta, flow hazards and water hazards. The best-known hazards of living near a volcano are the risks associated with ejecta. Most volcanoes vent dangerous gases, such as sulfur dioxide and hydrogen sulfide, that are toxic to animals. Volcanoes also eject ash and chunks of debris called tephra that can fall out over hundreds of square miles and bury everything in their path. Lava usually flows slowly, but it is glowing hot and burns through everything it comes into contact with.
Flow hazards around a volcano involve rockslides of various threat levels. Simple rockslides occur often on the slopes of active volcanoes as loose tephra from old eruptions suddenly gives way and falls down the grade. One special kind of landslide called a pyroclastic flow occurs when a dome collapses or the side of a volcano erupts. A pyroclastic flow resembles a gigantic shotgun blast of superheated rock that can level the surrounding countryside. A related, but more sinister, threat is the lahar. Lahars occur when water comes into contact with hot magma and begins flowing. Along the way, this hot flash flood picks up enough mud and rock to take on the consistency of wet concrete, and it can flow at speeds of up to 40 mph for up to 50 miles, devastating everything in its path.Learn more about Volcanoes
No two volcanoes are exactly the same, as they all have differences in dimensions of their mountains and craters, as well as their relative frequency and type of eruption. Volcanoes come in cinder cone, shield and stratovolcano varieties.Full Answer >
An ash cloud is a large cloud of smoke and debris that forms over a volcano after it erupts. Ash clouds consist of several elements, including ash, gases, dust, steam, rock fragments and other materials that come from inside the volcano and combine in the air above the crater.Full Answer >
Volcanic eruptions can either be effusive or explosive. An effusive volcanic eruption occurs when the lava pours out onto the ground from the volcano's vent. When the molten rock or magma is thin and runny, gases can easily escape and the lava flows freely and travels far. An explosive volcanic eruption is caused by thick and sticky magma, which prevents gases from escaping and causes them to explode violently.Full Answer >
The primary impact volcanoes have on the environment is the release of volcanic gases into the atmosphere. Volcanoes release around 130 million tons of carbon dioxide each year, as well as toxic pollutants like sulfur dioxide, hydrogen sulfide, hydrogen chloride and hydrogen fluoride. However, volcanoes can also have a positive impact on the environment because the lava and ash produced by an eruption contain valuable nutrients for the soil.Full Answer >