Different forms of effusive lava can provide different hazards. Pahoehoe lava is smooth and ropy while Aa lava is blocky and hard. Lava flows normally follow the topography, sinking … See more

Earthquakes can occur due to volcanic activity. These earthquakes could produce topographical deformation and/or destruction of buildings, homes, cars, etc. Two different types of these earthquakes can occur: volcano tectonic earthquakes and long period … See more

According to John Ewert and Ed Miller in a 1995 publication, "a great majority of the world's potentially active volcanoes are unmonitored". Of the historically active volcanoes in the … See more

Tephra is a generalized word for the various bits of debris launched out of a volcano during an eruption, regardless of their size. See more

When pyroclastic materials mix with water from a nearby stream or river, they can turn the watercourse into a fast moving mudflows. … See more

Large, explosive volcanic eruptions inject water vapor (H2O), carbon dioxide (CO2), sulfur dioxide (SO2), hydrogen chloride (HCl), hydrogen fluoride (HF) and ash (pulverized rock and pumice) into the stratosphere to heights of 16–32 kilometres (9.9–19.9 … See more

Prehistoric
A volcanic winter is thought to have taken place around 70,000 years ago after the supereruption of Lake Toba on Sumatra island in Indonesia. According to the Toba catastrophe theory to which some anthropologists and … See more