Dangerous volcanoes: Five of the most threatening active volcanoes around the world

There are 1,500 active volcanoes in the world, but these five pose some of the biggest threats to human life, according to AccuWeather. There tends to be much media talk over certain popular volcanos such as Yellowstone and Mt St Helens, however, there are so many unknown volcanoes that if erupted tomorrow would cause worldwide devastation. Here is a list of the 5 carefully watched volcanos. These volcanos are rated due to the population surrounding the volcanos, their potential Volcanic eruption index (VEI) and their past and current activity.

Galeras volcano 

Image from https://galerasvolcano.weebly.com

Galeras volcano is the most active volcano in Colombia. A city of nearly half a million residents sits on the mountain's eastern slope. In an eruption in 1993, the volcano killed a group of scientists and tourists who had been inside its crater when it erupted. The dominantly andesitic volcano has been active for more than 1 million years, and two major caldera collapse eruptions took place during the past 100,000 years.

Several collapse events have produced debris avalanches that swept to the west and left a large horseshoe-shaped caldera inside which the modern cone has been constructed a central cone slightly lower than the caldera rim has been the site of numerous small-to-moderate historical eruptions since the time of the Spanish conquistadors.

Galeras became active again in 1988 after 10 years of dormancy. It became infamous when it erupted on 14 January 1993, killing six volcanologists and three tourists who were inside the crater when it exploded. The group was part of a scientific conference excursion and their final decision to enter the crater, pushed forth by team leader Stanley Williams (who miraculously survived), was and still is highly debated. The fatal decision was made despite the observation of a significantly increased number of particular earthquakes, which had preceded previous eruptions and also started to occur in the days before the eruption.

To enter the volcano was clearly a grave mistake, however, this does elaborate the unpredictability of volcanoes and in this case the volcanologists may have become comfortable and confident with Galeras and underestimated the volcanoes unpredictable nature.

Sakurajima volcano

Image from https://www.nippon.com/en/features/h00194/

Sakurajima volcano was a separate island until the 1914 eruption connecting it to Japan's mainland. It sits near a city of more than 700,000 people. The volcanic activity still continues, dropping volcanic ash on the surroundings. Earlier eruptions built the white sands highlands in the region. The most recent eruption started on May 2, 2017.

On September 13, 2016, a team of experts from Bristol University and the Sakurajima Volcano Research Centre in Japan suggested that the volcano could have a major eruption within 30 years. Sakurajima is a stratovolcano. Its summit has three peaks, Kita-dake (northern peak), Naka-dake (central peak) and Minami-dake (southern peak) which is active now.

On Saturday morning June 16, 2018, at 7h19 AM local time a strong explosion occurred from Sakurajima’s Minamidake crater. The eruption created an ash plume that rose about 4700 meters above the crater and then drifted to the west.

There were observations of pyroclastic flows running down the volcano’s southwest flank and significant ash falls were reported to cover Kagoshima. Sakurajima's present-day volcano is a new volcanic cone inside the 17 x 23 km wide Aira caldera forming the northern half of Kagoshima Bay.

The caldera formed around 22,000 years ago during a Plinian eruption that produced large pyroclastic flows. Around 13,000 years ago, another smaller caldera, the so-called Wakamiko caldera was formed in the NE corner of the Aira caldera and was partially filled by volcanic cones.

One of the new vents in this caldera eventually became present-day Sakura-jima located on the southern rim of Aira caldera. Sakurajima's early activity took place mainly at the Kita-dake summit cone until about 4,850 years ago, after which its vent shifted to Minami-dake.

The construction of Sakurajima formed a new island that was joined to the Osumi Peninsula during the major explosive and effusive eruption of 1914.

Popocatepetl volcano

Image from https://volcano.si.edu/volcano.cfm?vn=341090

Popocatepetl volcano is just 35 miles away from Mexico City and the 18 million residents throughout the city's metro area. Popocatepetl is one of Mexico's most active volcanoes. After almost 50 years of dormancy, "Popo" came back to life in 1994 and has since then been producing powerful explosions at irregular intervals.

In the past centuries before European invasions, large eruptions produced giant mudflows that have buried Atzteque settlements; even entire pyramids. The glacier-clad stratovolcano contains a steep-walled, 250-450 m deep crater.

At least three previous major cones were destroyed by gravitational failure during the Pleistocene, producing massive debris-avalanche deposits covering broad areas south of the volcano. In early 2018 Popocatepetl had erupted again after a 7.2 earthquake. This is the incredible moment when Popocatepetl volcano explodes into life sending a huge cloud of smoke into the sky and flaming debris flying.

Just two months before that, Mexico had another eruption from the same volcano, after a previous earthquake.

Mt. Vesuvius

Image from https://science.howstuffworks.com/

Italy's Mt. Vesuvius famously destroyed Pompeii and Herculaneum nearly 2,000 years ago. The region is now home to 3 million people. When it comes to Italy's Mount Vesuvius, ­it is not a question of if it erupts, but when.

Geologists and volcanologists who study the volcano readily concede that Mount Vesuvius is overdue for an explosion. For that reason, the Vesuvius Observatory monitors seismic activity, gas emissions and other indicators 24 hours a day to know at the earliest point when it may blow. The infamous volcano is best known for its nearly instantan­eous decimation of neighbouring towns Pompeii and Herculaneum in A.D. 79.

Considered one of the world’s most dangerous, it is also the only active volcano on Europe's mainland. Nevertheless, 600,000 people live in the 18 towns at its base that comprise the "red zone." It is this red zone that denotes the populated area that would bear the brunt of an ­eruption.

Directly in the line of fire, the 9-mile (12-kilometre) the radius of people stands little chance of survival when Vesuvius explodes again. Because of the imminent -- and unpredictable -- threat, the Italian government has devised an evacuation plan to clear out the red zone 72 hours ahead of an impending eruption.

Beginning in 2004, the government also set up a program to pay people $46,000 (30,000E) to relocate outside of the zone -- though it has had relatively few takers. Experts warn that emergency plans should also include nearby Naples since an explosion could send dangerous burning ash and pumice as far as 12 miles (20 kilometres), just like that seen in A.D 79.

Yellowstone Super-volcano

Image from https://www.scenic-safaris.com

Yellowstone supervolcano may be home to stunning geothermal features, but a ticking time bomb lurks below. Its power can devastate half the United States. Yellowstone National Park in the US states of Wyoming, Montana and Idaho is a popular 9000sq km tourist attraction with wildlife, dramatic scenery and geothermal wonders.

The United Nations world heritage site, which lies over giant chambers of molten magma is actually the world’s largest super volcano, which erupted 2.1 million, 1.3m and 640,000 years ago, causing massive the devastation across the planet.

By the latest estimate, it would take several centuries for both sides of the Niagara Falls to fill up just its shallow chamber, let alone it is far more voluminous deeper reservoir. What would happen if much of this suddenly re-emerged in a horrific supervolcanic eruption?

Right now, the two-step magma chamber is in a state of dormancy. Throughout most of its life, the region has featured extensive lava flows or (far more frequently) hydrothermal blasts, which suggests that any future eruption is far more likely to replicate this.

Although these will cause a problem, they certainly won’t be anything apocalyptic – and even these eruption types are exceedingly rare. However, other scientists do suggest otherwise, I guess we will only know if it erupts, let us just hope that day does not arise.