How Volcanoes Affect Humans and the Course of Our History

Part 2 of Volcanoes and Our World

A couple of weeks ago, we explored how volcanoes have played a critical role in the development of our planet while profoundly influencing the course of evolution. This week, we’ll be exploring how these sculptors of our world have also altered the course of our human history.

Volcanoes affect humans in many ways, some of which are beneficial, while others are truly disastrous. We have a love-hate relationship with these formidable forces of nature. At one time, they almost spelled the end of humanity but, at the same time, we couldn’t live without them.

Volcanic activity shapes new habitats by forming virgin lands, while enriching the soil with nutrients that allow life to thrive. They create stunning landscapes as well, generating tourism that some countries, such as Iceland, rely heavily on for supporting their economy.

On the other hand, a volcanic eruption can be one of the most destructive of all the forces of nature. Pyroclastic flows have wiped entire towns and villages off the face of the Earth, wreaking havoc by displacing entire populations, disrupting economies and destroying the environments that they helped to create in the first place.

Bringers of the Apocalypse

Pixabay

Don’t be deceived by the serene beauty. Lake Toba in Indonesia was the site of an eruption that almost wiped out humanity.

There’s little doubt that volcanoes have been instrumental in wiping out countless species during major extinction events. The largest volcanic eruptions result in flood basalts, vast swathes of molten lava that are among the most destructive of all Mother Nature’s weapons.

Flood basalts resulting from supervolcanic eruptions have been credited with the worst mass extinction ever – that which occurred at the close of the Permian. One of the most famous flood basalts, however, are the Deccan Traps in India, which cover almost 200,000 square miles (500,000 km²). They formed during an enormous eruption towards the end of the Cretaceous Period, leading palaeontologists to believe that it may have played a role in the extinction of the dinosaurs, in addition to the impact event.

It wasn’t just the dinosaurs that had a poor relationship with volcanoes. Our own human ancestors may have been reduced to an endangered species by a supervolcano some 75,000 years ago. The eruption of Toba, in the Indonesian island of Sumatra, undoubtedly had profound effects on human migration patterns, with some estimates claiming that the total global human population may have been reduced to a paltry 2,000.

The Toba catastrophe theory suggests that the eruption, which was the largest by far in the last 25 million years, led to a volcanic winter and greatly reduced global temperatures. Living in the shadow of this ancient apocalypse, our distant ancestors would have suffered centuries of global cooling in the form of a short ice age. As a result, the human population became fragmented and isolated, ultimately leading to the extinction of the Neanderthals and Denisovans around 40,000 years ago.

Lake Toba is just one of many volcanic formations in the Indonesian islands, which form one of the most geologically active regions on the planet. Only as recently as 2004 did the Indian Ocean earthquake and consequent tsunami claim the lives of up to 280,000 people across 14 countries.

A Year without Summer

Paul Hessels

Though now a popular destination for hikers, Mount Tambora is still very much alive and is being monitored closely.

Volcanoes have claimed countless lives throughout human history, and almost everyone has heard of events such as the eruption of Mount Vesuvius in A.D. 79 and that of Krakatoa in 1883. However, even these famous eruptions pale in comparison to the explosion of Mount Tambora in 1815.

The 1815 eruption of Mount Tambora was one of the most powerful in recorded history, and one of only a very few to hit a volcanic explosivity index of seven. Located on the Indonesian island of Sumbawa, which was then part of the Dutch East Indies, Tambora may have claimed as many as 100,000 lives.

The wrath of Tambora completely decimated agriculture in the region 200 years ago, resulting in thousands of people starving to death. However, the effects extended far beyond southeast Asia. In fact, the initial eruption was so monstrous that it could be heard from 1,600 miles away, where it was first mistaken for mortar fire. This terrifyingly loud detonation was rivalled only by the 1883 eruption of Krakatoa, also in Indonesia, which was heard some 3,000 miles away.

Despite being better known, the eruption of Krakatoa was still not in the same league as that of Mount Tambora. In fact, the still-active stratovolcano ejected about 10 billion tonnes of rock, and the entire mountain was described as transforming into a vast mass of liquid fire. The rain of ash covered areas as far away as 800 miles (1,300 km).

Tambora’s fury was felt across the entire globe to such an extent that the year following the eruption was forever known as the Year without a Summer or, more poetically, Eighteen Hundred and Froze to Death. With the colossal amount of ash blocking out the sunlight, global temperatures dropped significantly, leading to one of the most severe winters in recorded history. This formidable event lead to serious food shortages across Europe, North America and elsewhere in the world.

The Year without a Summer saw heavy snow falling and lakes freezing over as late as June in New England, and things weren’t much better in Europe and Asia either. Europe, in fact, suffered the worst famine of the nineteenth century, while climate change saw torrential rains lead to a massive outbreak of cholera in Asia. Meanwhile, the United States sank into its first major economic depression, which was partially triggered by the disastrous effects that the eruption had on agriculture.

Powering the Future

Pixabay

Harnessing the natural power of the Earth, geothermal plants deliver clean and renewable energy.

Though they can be frighteningly destructive, volcanoes can also have positive effects on human cultures. The economy of Iceland, for example, largely revolves around geological activity, both for its tourist industry and for its energy requirements.

In fact, in 2014, scientists working on the Icelandic Deep Drilling Project even discovered a new way to use the country’s many volcanoes to satisfy modern energy requirements.

By drilling beneath the surface and tapping into underground rivers of molten rock, a volcano-driven power plant could heat water to a supercritical state by pumping it over molten lava. The resulting steam could then be used to drive enormous turbines, thus creating usable electrical energy.

Unsurprisingly, the Land of Ice and Fire is a pioneer in the use of geothermal energy. The incredible dynamism of the country ultimately allows for geological activity to provide over a quarter of its electricity and almost all its heating and hot water. In fact, so pronounced is the geological liveliness of Iceland that you can actually smell volcanically produced elements, such as sulphur, whenever you turn on a tap.

Another place where the volcanic energy is being harnessed is the US state of Hawaii, which is home to five active volcanoes. Indonesia, the most volcanically active place on the planet, is also hoping to tap into geothermal power, although the overwhelming majority of its energy still comes from coal-burning power plants.

Of course, volcanic power is not without its risks. While it provides a practically inexhaustible supply of power that’s much more reliable than wind or sunlight, the possibility of an explosive catastrophe is always a concern. One thing is for certain, however, is that governments and private enterprises alike need to do everything in their power to tap into this invaluable natural resource and bring an end to the world’s ongoing energy crisis.