With its glowing lava flows and ash clouds, Kilauea volcano in Hawaii has caught the world's attention. But how dangerous are such eruptions?
Every year about 60 volcanoes erupt. Some of them surprise us, others are regular perpetrators.
Kilauea is one of the world's most active ̵
His lava flows literally erupted in the backyards, but thankfully only one serious injury was reported – a man hit on his balcony by projectile molten rock.
This may indicate that volcanoes are aren. This is dangerous, but a large part of the world's population lives near an active volcano – and many of them are much more deadly than Kilauea.
Since the year 1500 about 280,000 people have been killed by volcanoes – 170,000 of them by only six eruptions.
We compiled these numbers using media reports, public records and historical documents.
About 2,000 people have been killed since 2000.
Most of these deaths were caused by volcanic mudflows in the Philippines, pyroclastic flows in Indonesia, lava flows in the Democratic Republic of the Congo and volcanic projectiles in Japan. Last year, three tourists died in Italy when they fell into a pit in a volcanic crater.
There are currently around 800 million people living within 100 km of an active volcano – a distance that is within reach of potentially deadly volcanic dangers. Of these, about 200 million are in Indonesia.
As populations continue to grow, more people are likely to be home near one of 1,500 active volcanoes in the world, spread over 81 countries.
Active "does not mean that all these volcanoes erupt, but that we think they have been active recently and are capable of new eruptions.
Volcanoes represent many different species Danger for those living near them.
In the case of Kilauea, the United States Geological Survey has a marked increase in seismic activity at the end of April, first cracks in early May
Since then, lava flows are about three miles (5 km) have traveled to the ocean, destroying houses and leading to the evacuation of thousands of people.
Such lava flows do not kill many people.
As it burns and buries everything in its path, lava – molten stone that is red-hot , with temperatures of about 1200 ° C – slow enough that people can usually just run away.
The danger arises when people do not evacuate quickly. In Hawaii, several people were taken to safety after their escape routes were cut off.
Lava can cause explosions, including the inflammation of pockets of methane gas that results from burying vegetation.
And when it reaches the ocean, it makes unstable new land and loafs – feathers of steam, hydrochloric acid and broken glass.
Another danger in Hawaii is sulfur dioxide, one of several gases that can be released by volcanoes, even if they do not break out.
However, lava and gas together make up less than 2% of registered volcanic deaths.
The largest loss of life due to volcanic gas was in 1986 in Cameroon, when more than 1,500 people were killed as carbon dioxide from Lake Nyos flowed into the surrounding villages.
Most people killed by volcanoes are victims of pyroclastic flows and lahars – volcanic mudflows filled with debris – which were responsible for about 120,000 deaths in the last 500 years.
with large conical volcanoes found at tectonic boundaries, such as the Ring of Fire, as opposed to the gently sloping shield volcanoes, such as Kilauea.
Pyroclastic flows are very fast avalanches of rock, ash and gas that can reach temperatures of 700C. 19659004] They destroy everything on their way, and death is almost certain for anyone caught in their path.
These were pyroclastic streams that destroyed the Roman city of Pompeii in 79 AD. In 1902, they claimed nearly 30,000 lives on the Caribbean island of Martinique.
Other stories like this :
Lahars may contain rocks, trees and even houses.
They form as precipitation, snow or melting ice and wash ash deposits at high speed from the slopes of the volcanoes and into the surrounding valleys.
In 1985, about 25,000 people were killed by Lahars in Nevado del Ruiz, Colombia.
Volcanic ash can travel hundreds or even thousands of kilometers during large eruptions. It can bury large areas and disrupt transportation and critical services.
Historically, famines and diseases have followed such events with crop failures or ashes and gas, leading to temporary climate changes.
Although volcanic eruptions do not have to be halted, they do not necessarily lead to death and catastrophe.
The report of only one serious injury in Hawaii is testimony to the work of observatories and civil protection authorities, as well as excellent surveillance systems.
Unfortunately, due to limited resources, only a few volcanoes around the world are as well monitored as Kilauea.
Satellite monitoring allows observation of even the most distant volcanoes, but only about 20% of the world's volcanoes have ground-based monitoring.
And about every two years, a volcano erupts that contains no historical records.
These can be the most dangerous, as long periods of rest can lead to more explosive outbursts and the people living near them are the least prepared.
Nonetheless, volcano observatories, researchers and international organizations are working tirelessly to respond to emergencies and forecasted events, resulting in many tens of thousands of lives being saved.
Of course, volcanoes do not have to kill people to have a significant impact.
Evacuations uproot people from their homes, livelihoods are lost, agriculture is devastated, and economic loss can be billions.
Even if they seem to sleep It would be wise to continue watching the volcanoes of the world.
About this work
This analysis object was commissioned by the BBC by an expert for an external organization.
Dr. Sarah Brown is a Senior Research Associate in Volcanology at the University of Bristol. She focuses on volcanic records, past activities, human impact and risk communication.
Edited by Duncan Walker