Nowadays, we know volcanic eruptions are a result of glowing hot magma being forced up from the mantle through vents in the earth's crust. Of course, that doesn't make their explosive effects any less devastating.
Magma and Lava
What exactly is a volcano?
it can be defined as a vent in the earth's crust through which lava, rock fragments, hot vapor and gases are ejected. In other words, a volcano is the earth's way of letting off a little steam.
The super-heated particles that eject out of a volcano come from deep below the earth's surface where temperatures can become so hot that rock actually melts. Magma is the term used to describe this hot molten rock from deep within the earth.
A volcano begins to form when magma, which is less dense than the rock it originated from, rises toward the earth's surface. This liquid rock collects in chambers called 'magma chambers,' where pressure builds due to expanding steam and gases associated with the magma. As pressure reaches a peak within these chambers, magma finds its way through a vent or fissure in the earth's surface, resulting in a volcanic eruption and the expulsion of the hot molten rock.
We now have hot molten rock outside of a volcano, and its name changes from magma to lava. So you can think of 'magma' as liquid rock in the 'middle' of the earth and 'lava' as liquid rock that's 'leaving' the earth.
Here is a list of volcanoes most likely to erupt and wreak tragedy on surrounding communities and the environment at large:
10 Most Dangerous Active Volcanoes Around The World:
- The five principal types of mass movements such as falls, topples, slides, lateral spreads, flows and sixth as complex which is a combination of two or more principal types of movements and the recommended control measures are summarized .
Yellostone Caldera, USA
Unlike traditional volcanoes, super volcanoes don't have a cone shaped mountain, instead they form what are known as calderas – the sunken areas that are left over from previous super volcano eruptions. Essentially, all of Yellowstone is a giant caldera, ready to blow and devastate humanity. Experts estimate that a Yellowstone eruption would kill 87,000 people immediately, while the clouds of ash and gas would enter the jet stream and have untold effects on the world's food supply.
Mt. Vesuvius is the only volcano to have erupted on the European mainland within the last hundred years, and is probably most famous for its massive eruption in 79 AD, when it buried the cities of Herculaneum and Pompeii.
Popocatépetl is a large, glacier covered peak that lies around 35 miles from Mexico City. Around 9 million people live within Popocatépetl's blast radius, and it has erupted more than 20 times since 1519. It last erupted in 2000. Thank fully, preventative evacuations of 41,000 people from surrounding towns prevented a major catastrophe.
This composite volcano in Japan was once its own island, but lava flows in its 1914 eruption caused it to connect to the mainland. Many experts refer to it as the "Vesuvius of the east", due to its high level of volcanic activity.
While it went dormant in 1978, it went active again in 1988 after just 10 years. When scientists held a Decade Volcano conference in 1993 to address the dangers of Galeras, an unexpected eruption occurred, killing 6 scientists and 3 tourists. Since 2000, it has erupted almost every year, spouting out ash and lava and causing tremors in the region.
Mt. Merapi's infamous lava flows usually travel around 3-4 miles from the peak, though some eruptions cause lava to flow as far as 8 miles. These lava flows can travel as fast as 70 miles per hour. In 2010, an eruption killed 353 people and left 320,000 local residents homeless.
Mt.Nyiragongo,Democratic Republic of Congo
Mt. Nyiragongo is one of the most active volcanoes on the African continent. It's well known for its large lava lakes, which frequently appear in its crater. Nyiragongo poses a unique threat to surrounding communities, as nowhere in the world does a steep sided stratovolcano carry such a large lake of fluid lava.
Ulawon,Papua New Guinea
Due to its height, the biggest threat posed by Ulawun is a catastrophic structural collapse, which could generate an eruption that would cause devastation to 100s of square km of surrounding land.lawun,Papa New Guinea.
The Taal Volcano is a cinder cone volcano. It is located on the island of Luzon, Philippines where it lies at the middle of Lake Taal. It lies just 31 miles from Manila – the capital of the Philippines and home to 1.6 million people.
Another rarer, but potentially more devastating hazard posed by Mauna Loa is the potential for massive landslides triggered by a collapse of the volcano's flanks. Such a collapse is rare, but it can cause severe earthquakes and megatsunamis.