What If Every Volcano Erupted At the Same Time?

What If Every Volcano Erupted at the Same Time?

Volcanic eruptions are amongst Mother Nature’s scariest spectacles. And the explosion of just one volcano is dangerous enough to wipe out entire villages, towns, even civilizations. The infamous eruption of Mount Vesuvius in the year 79 AD was one of the largest in European history, releasing 100,000 times more thermal energy than the atom bomb and ejecting a dangerous cloud of gas over thirty kilometers into the atmosphere. The nearby cities of Herculaneum and Pompeii were completely obliterated by falling ash and dangerous surges of molten rock and debris, leaving thousands dead, and burying both cities for over a thousand years.

And, that was just one eruption from just one volcano. So, what kind of carnage would be caused if every active volcano on Earth – and there are at least 1,500 of them – blew up at the same time?

While estimates do vary, around 500 million people live on a volcano – or close to one. So, the initial death toll would inevitably be huge. Say the widespread eruption occurred without any prior warning, then finding a safe spot could prove almost impossible for anyone nearby. In terms of immediate effects for those that did survive, millions would be left deaf. The 1883 eruption of Mount Krakatoa in Indonesia still stands as the loudest sound in recorded human history. Estimated to have measured at an inconceivable 300 decibels plus, it was loud enough to shatter the eardrums of sailors working over forty miles away, and was audible even to people living 3,000 miles away. While Krakatoa does come in at the very top of the scale, the noise created should every volcano blow could feasibly envelop the entire planet – leaving everyone well aware that catastrophe was unfolding.

For those without a volcano on their actual horizon, the first signs of danger may actually play out on the coast. Because, the mass eruptions would be quickly followed by massive tsunamis – triggered by the earthquakes that often accompany volcanic events, as well as the large-scale displacement of seawater by debris. Following the Krakatoa explosion, the nearby port town of Merak was completely destroyed by a 150-foot tall wave, while additional tsunamis struck as far away as South Africa. Consider that similar effects would take hold all at once, all around the world, and Earth’s seas and oceans suddenly become brutally unpredictable. Every coastal settlement would be at risk, as the tides become impossible to track, to the point where even the world map itself could be changed beyond recognition.

But, perhaps you live in a land-locked country, without a major volcano on your proverbial doorstep... Your first sign of trouble would be the sudden appearance of an extremely dense cloud of gas and ash, probably from all sides, blanketing everything before it and effectively blocking out the sun. It’d plunge the planet into a Nuclear winter – similar to that experienced after the Cretaceous-Paleogene extinction event, otherwise known as the asteroid that wiped out the dinosaurs.

Not only would our world plummet into unending darkness, though, but temperatures would universally drop, agriculture would completely collapse, the growing of anything edible would be next to impossible, and all types of power would eventually switch off. Developments that’d send humanity back over 10,000 years, we’d be forcibly returned to our hunter-gather beginnings. Even if not directly affected by the eruptions themselves, millions would undoubtedly perish through starvation or sickness, ranging from various deficiencies linked to a lack of vitamins or sunlight, to respiratory problems caused by atmospheric damage. Plus, as the ash cloud settles, it’d literally cripple our cities, with buildings collapsing from the sheer weight of the residue falling onto them.

And yet, it isn’t only the ash we’d need to worry about. Other toxic substances emitted by volcanoes include (but are not limited to) hydrochloric acid, sulfur dioxide, and hydrogen sulfide. These horrific and dangerous gasses would condense in the atmosphere and fall as acid rain, damaging and killing the few crops that may have survived, as well as contaminating otherwise safe water sources, and killing off countless marine species.

Eventually the planet would (somewhat paradoxically) enter a new ice age. The sulfur dioxide would convert to aerosols within the atmosphere, and these aerosols would reflect sunlight back into space – rather than absorbing it into the Earth. With an impenetrable barrier between us and it, the sun’s energy would fail to reach us, and Earth would drastically cool.

But, these changes wouldn’t be permanent, and eventually the extreme reverse could occur. Past extinction events have taught us that an expulsion of carbon dioxide could happen next, which would overcome the cooling effects, leaving Earth to essentially cook itself to death. Thanks to the untold damage of mass eruptions, we could ultimately see the greenhouse effect let loose, boiling away the oceans, transforming our familiar Earth into something closer to Venus – a planet without surface water, that’s unimaginably hot.

Clearly, at this point, all life on Earth, mammals and plants alike, would’ve been wiped out – with the possible exception of microbes and extremophiles, the hardiest organisms on the planet.

But, that’s still not the worst of it. Because, even Earth’s most fundamental truths may be put in jeopardy, as the entire planet could shift and rotate in its orbit. Massive and prolonged eruptions could dump so much molten material onto the planet’s surface that it’d experience a massive imbalance – becoming top heavy in particularly volcanic places. In fact, evidence suggests that this very thing happened on Mars roughly three and a half billion years ago – tipping the Red Planet upwards of 20 degrees.

So, simply put, if every volcano in the world really did erupt at the same time, the Earth would descend into pure chaos. Tsunamis, floods and worldwide hearing problems would be followed by an indiscriminate, impenetrable ash cloud, which would trigger an ice age before unprecedented global warming, and even possible changes in the Earth’s axial tilt. Life as we know it would disappear, and our planet would likely emerge out of the ordeal as an unrecognizable husk of the world it once was. It’s a hypothetical world that’ll never actually happen, but few alternative realities are quite as bleak as this one!