There are over 1,500 active volcanoes dotted on the face of the earth. There are even many more unknown volcanic ranges at the bottom of oceans and other water bodies. These submerged volcanoes erupt at the rate of one every day. Though scientists claim that the chances of all the volcanoes erupting all at once are very slim, in case they did, the earth would not be able to survive all the molten lava, ash and scorching gasses that volcanoes churn out. It would be the end of our beloved Earth as we know it.
The closest this has ever come to reality was during the Cretaceous period over 90 million years ago. Evidence deduced by scientists suggests massive volcanic explosions rocked the Earth, causing a distraction that has never been seen to date. Carbon dioxide levels rose and marine life was completely wiped out.
While molten lava is hot and destroys everything in its path, the liquid rock is usually so dense and nonvolatile that it does not move far, removing the chances of heavy damage. The greatest danger posed by all volcanoes erupting at the same time is the layer of ash that would cover the earth and could last up to 10 years. According to Parv Sethi a geologist at Radford University in Virginia, “The planet would be pitched into complete darkness, and that is going to devastate photosynthesis, destroy crop yields and cause temperatures to plunge.”
Though not all volcanoes emit ash, some like the ones in Hawaii just produce a steady stream of lava, 1500 volcanoes is a huge number. Besides, one active volcano like the Yellowstone supervolcano, which last erupted 70,000 years ago, can produce enough ash capable of covering the entire United States!
Reduced sunlight penetration
If all volcanoes were erupting at the same time, the effects of the thin layer of ash that would cover earth would be disastrous as that layer would block out the sun. This would mean plants would not be able to grow or make their own food, leading to a famine of unimaginable proportions.
Temperatures would drop as well due to the gasses contained in the composition of the ash such as hydrochloric acid, sulfur dioxide, and hydrogen sulfide. These gasses would condense and create acid rain which would contaminate all ground water, finish off any plant life still standing, and kill marine life corals. Even creatures with the hardest of shells would not be spared from acid rain.
Carbon dioxide emitted from volcanoes has the ability to cool the planet as witnessed in the 1991 explosion of Mount Pinatubo where temperatures dropped by around 0.4 degrees Celsius and stayed that way for two years. But if 1500 volcanoes erupted at once, the Earth would surely suffer from carbon dioxide poisoning.
What would survive?
According to Sethi, the only creatures that can survive on Earth in such conditions would be extremophiles. These animals thrive in extremely acidic conditions. These are animals, mostly found in the deepest parts of the ocean. In essence the surface of the Earth would not have any life forms.
Although a scenario like this is highly unlikely to take place, it is certain that life would be unbearable, and Sethi couldn’t have put it better, “Things will become so sick, I wouldn’t want to survive on an Earth like this. The lucky ones’ will be the dead ones in this scenario.”