Scientists simplify things to help laypersons understand volcanoes. The reality is of course more complicated.
Every volcano is unique. Volcanologists need to get to know each and every "personality" and story when trying to help people nearby.
But how do you select the volcanoes to be investigated with limited resources? Here's how.
When the United Nations celebrated its international decade of natural hazard reduction in the 1990s, volcanologists decided to focus on 16 volcanoes – two each from the United States, Japan, and Italy. one each from 10 other countries.
One of these ten volcanoes ̵
16 Taal Volcano, Philippines
Taal made international news with its dramatic eruption in January 2020. The current situation is still volatile, so let's consider it a ten-year volcano.
Well over 20 million people live near Taal, just 30 miles south of Manila, the nation's capital.
Human risk alone made Taal a candidate for the list of ten volcanoes in the 1990s.
But Taal has also been very active over the centuries, as have a few eruptions in the distant past that were powerful enough to leave craters – basically holes – that eventually filled with Lake Taal.
Communication is also important in volcanology. Scientists and regional planners worked together on the Decade Volcano program to limit intense development in the caldera. This foresight has probably made the current crisis somewhat easier to deal with.
15 Avachinsky-Koryaksky, Russia
Endangered population: Over 200,000 people live within 100 km of these two volcanoes on the Kamchatka Peninsula in the Far East of Russia.
Last known eruption: Avachinsky, 2001; Koryaksky, 2009.
The flip side of living near an active volcano? All the fun you can have during a quiet spell!
The people in the video, for example, climbed Avachinsky on a sunny day and also have an excellent view of nearby Koryaksky.
Avachinsky looks so solid there. It is hard to believe that this volcano sometimes collapses. Nearby Petropavlosk – the largest city in Kamchatka – was built on the deposits of such a prehistoric catastrophe.
Mud rivers and lava are more likely and can occur on both volcanoes.
Petropavlosk is so isolated that its residents have to wait for help by land and sea during a volcano emergency.
14 Colima, Mexico
Endangered population: 1.5 million
Last known eruption: 2019.
Colima, a complex volcanic center near the west coast of Mexico, also harbors several dangers To be population centers.
For one thing, violent outbreaks often occur: As here in 2017, which were recorded by surveillance cameras.
Almost all of the decade volcanoes are located in subduction zones that normally produce explosive volcanism.
Such explosions cause explosions effects, ballistic rocks and lava bombs as well as pyroclastic currents. As you can see, they even light forest fires.
And Colima always does this. There have also been several large rubble slides in the past millennia.
After the list of ten volcanoes had been drawn up, new hazard maps for Colima were created and the monitoring post was restructured.
13 Etna, Italy
Endangered population: A quarter of the entire population of Sicily lives on the slopes of Etna
Last outbreak: 2020
Everyone knows this outbreak!
Mount Etna is a UNESCO World Heritage Site A look at the spectacular lava flows shows why Mount Etna was selected as a ten-year volcano.
The footage shown above was taken in 2011 near the city of Zafferna, which exists today only because of coordinated efforts in 1992 that managed to block and then divert a lava flow that threatened to overwhelm the city Eruption.
Lava and occasional hydrothermal explosions like this are the main dangers on Etna. However, Sicily is highly dependent on Etna tourism and agricultural products grown on the volcano. Therefore, any increase in activity would also have a negative economic impact.
12 Galeras, Colombia
Endangered population: almost two million.
Last known eruption: 2014.
A tragedy occurred on this flat stratovolcano in 1993 when some tourists as well as six volcanologists who took part in a decade volcano workshop were killed by an unexpected eruption.
Activities in Galeras before and during this risky excursion were, of course, closely monitored, but never before had anyone seen the seismic signals that were called "tornillos" shortly before the explosion.
Now everyone knows that tornillos are warning signs of an impending explosion – a scientific discovery that was associated with high costs.
Galeras is one of the most active volcanoes in Colombia. Above that, the 2008 fireworks light up the sky above the nearby town of Pasto.
The dangers include debris flows, large eruptions with heavy ash fall and pyroclastic flows.
11 Mauna Loa, USA
Vulnerable Population: 175,000
Last Known Eruption: 1984
You'd think Mauna Loa is just such a long, low mountain near Kilauea – the Hawaiian Volcano that had a spectacular eruption in 2018.
Mauna Loa is actually the highest active volcano on earth and rises almost 6 miles above the Pacific Ocean floor. It also has frequent outbreaks.
In 1984 a lava flow came within eight kilometers of the city of Hilo.
Lava is the main danger here, although Mauna Loa has also suffered some flank breaks in the past.
Fortunately, the Hawaiian Islands are nowhere near a subduction zone, and eruptions are usually not as explosive here.
Volcanologists are closely watching Mauna Loa as it appears to be slowly erupting, but saw no reason to raise the alarm level higher than now (yellow, lowest warning level).
10 Mount Merapi, Indonesia
Population: Almost 25 million
Last known eruption: 2019
During the Decade Volcano Program, great international collaboration focused on Merapi – it is one of the most active volcanoes Indonesia's in a densely populated region.
Merapi's eruptions are violent too, with long-lived pyroclastic flows.
In addition to these gray death clouds, the dangers at Merapi Lahars (an Indonesian word for mud rivers) and large landslides.
The worst outbreak of Merapi in 2010 killed over 100 people.
9 Nyiragongo, Democratic Republic of the Congo
Vulnerable population: Just over nine million people live within a radius of 100 km; A million of them are less than 32 kilometers from the summit.
Last known eruption: 2019.
This African volcano has a flat tip like Galeras in South America. Unlike galeras, Nyiragongo has been home to a number of lava lakes for centuries.
This is a fatal hazard as these lakes drain off every few decades and the lava is extremely fluid, which means that it travels long distances, even to the nearby town of Goma
This has happened twice recently: 1994 , during the civil war and again in 2002 when about 150 people died and enormous damage was done.
Unfortunately, war and social problems have limited the scope of international volcanologists can do here. However, local hands have set themselves the task of researching and monitoring this decade volcano.
8 Mount Rainier, USA
Vulnerable Population: Almost Three Million
Last Known Outbreak: AD 1450 (19th century outbreaks were reported but not confirmed)
This world famous landmark in near Seattle, Washington had its last major explosion – a VEI-4 outbreak – about 2,200 years ago.
But that's not the only danger. Mount Rainier, which is heavily glaciated, tends to collapse and causes enormous mud flows.
This has not happened in the recorded history.
The residents of Armero, Colombia, were not so lucky in 1985. The capped Nevado del Ruiz volcano did not collapse, its lava melted on the summit glaciers and sent a mud that devoured Armero and other communities and over 23,000 people killed.
There were many warnings, but nobody expected that. Thousands died who would have just run a few hundred meters to safety.
The Armero tragedy was a key factor for both the UN Declaration on Danger Reduction and the Decade Volcano Project.
Partly because of all this attention, Mount Rainier now has better surveillance and hazard mapping. In addition, there is some legislation to reduce future developments in high-risk zones and to raise public awareness of the threats here.
But many people near Rainier are still denying it. This is understandable, although very sad: it is human nature to never really believe that something bad can happen to you – until it happens.
7 Sakurajima, Japan
Endangered population: 2.6 million
Last known eruption: 2019
You may not have heard of this volcano, which is on the same island as Mount Fuji located, but further south.
The world-famous Fuji-san is a serious threat to Tokyo and the subject of intensive research.
Maybe the selection committee for the volcano has joined Sakurajima instead because this dangerous volcano is not so well known.
After all, you haven't seen the above in Tokyo.
But the 2013 video shows it One of the perils that citizens of the city of Kagoshima, less than eight kilometers from Sakurajima, are often exposed to.
The Sakurajima volcano was an island in Kagoshima Bay until 1914, when one of its explosive eruptions also triggered lava flows that connected it to the mainland.
Now thousands of people live in the area, children wear protective helmets there just in case it rains stones on the way to school.
6 Santa Maria / Santiaguito, Guatemala
Endangered population: 6,200,000.
Last eruption: 2019.
These are not two separate volcanoes, as is the case with Avachinsky and Koryaksky on Kamchatka.
Santa Maria is the stratovolcano and “Santiaguito” is the name of the lava dome complex near the summit.
Santiaguito often has smaller outbreaks. The domes also sometimes collapse, causing pyroclastic currents. Larger explosions and sludge flows are also possible.
Still, many people enjoy looking down on an eruption and taking silly pictures.
This dome complex has existed since 1929. when Santa Maria ended 27 years of violent outbreaks that killed over 7,000 people.
Santa Maria / Santiaguito's decade volcanic status has not yet led to many government-funded projects.
Guatemala has many volcanoes that require attention. Officials still have to convince themselves that preparing for another major outbreak is less costly here than coping with the consequences of a later outbreak.
5 Santorini, Greece
Endangered population: 67,500
Last known eruption: 1950.
Volcanologists are curious about the eruption story that Santorini – also known as Thera – has helped to make it look dramatic.
You have identified at least four caldera-forming events in the past 180,000 years. The most recent outbreak around 3,600 years ago was a VEI-7 outbreak.
This may have failed the Minoan civilization, which concentrated on the nearby island of Crete. Or not. Nobody is really sure what ended this amazing culture.
Thanks to the Decade Volcano program, Santorini now has its first modern volcano observatory. So far, swarms of seismic activity have been observed only occasionally, nothing that looks like an impending outbreak.
4 Teide, Canary Islands
Vulnerable Population: 766,000
Last Known Eruption: 1909
Indeed, the entire island of Tenerife is a complex of stratovolcanoes that have been active since the Miocene. The Teide is only the tallest and also one of the youngest.
Teide is located in the 6 x 11 miles wide Las Canadas Caldera, and the view from the top is immense!
These sulfur-producing fumaroles up there are the only visible signs of current activity. Teide also had a few swarms of earthquakes, but is otherwise calm.
3 Ulawun, Papua New Guinea
Vulnerable Population: 61,000
Last Known Eruption: 2019
You may not have heard of this island volcano in the South Pacific, but (along with contributions from a Russian fire mountain, also obscure) ) Ulawun gave you purple sunsets last year!
Ulawun is one of the most active volcanoes in Papua New Guinea. Although the eruptions were explosive, they were relatively minor until the 1970s. From that point on, major explosions became more common, including a VEI 4 eruption in 2000.
This beautiful tropical stratovolcano is now behaving like one of the gentle planet daily reporters. We just have to stay tuned and see what happens next.
2 ounces, Japan
Endangered population: 7,300,000
Last known eruption: 1996
Yes, this is the one where the volcanologists Harry Glicken, Katia Krafft and Maurice Krafft together with 40 other people were killed in 1993.
Unzen is not so much a single volcano, but a mashup of three large stratovolcanoes and several lava domes that occupy most of the Shimabara Peninsula east of Nagasaki.
Pyroclastic flows are a great danger here. And sometimes collapsing material falls into the sea and tsunamis occur as in 1792, making up the majority of the 14,000 ounce victims this year.
Unzen woke up in 1990, forced evacuations, and destroyed more than 2,000 buildings near Shimabara City.
Now everything is silent. If Unzen moves again, activity forecasts will be more accurate thanks to data from decade volcanic studies and other research.
1 Vesuvius, Italy
Endangered population: More than 6 million.
Last known eruption: 1944.
You knew Vesuvius would be on the list, all because of the video above.  This is how a VEI 5 eruption looks up close. The only typical volcanic hazards that are not shown in this animation are lava, gas, and tsunamis, although everyone claimed victims that day.
Pyroclastic rivers, lava and gas have killed people and caused massive damage in other Vesuvius eruptions. including the last one in the 1940s. Tsunami-creating landslides in the Bay of Naples are also possible.
Although the dangers have been known to everyone here for centuries, the problem was first addressed as part of the Decade Volcano Program. There are now contingency plans based on the Pompeii outbreak and another massive outbreak in 1631 that are regularly reviewed.
Evacuating Naples and the surrounding areas is not easy, but Vesuvius will not catch scientists and rescuers the next time they sleep to live.
The worst volcano in the world will always be the one that erupts near you, whether on a scientific list or not.
But thanks to the Decade Volcano program, lessons have been learned that help people survive and manage a volcanic crisis wherever it occurs.