With all the continuous bombardment from all quarters about political-this, and war-that, sometimes, we need to step back, take a breath and consider something completely different. There are more things in theworld than politics, war or even high-tech-that-really-isn’t.
And this week, we’re going to revisit something that people don’t like thinking about, because they have been taught that they can do nothing about them, and neither can their governments…Like most things in this arena, though, that is not really true. So, this week, we’re going to talk about the “End of the World“.
While this was quite a popular topic about fifteen years ago, that is over a century in both dog and TV years…but the subjects still remain…Earth’s history includes numerous catastrophic events that dwarf anything in human experience. While rare, these “megadisasters” remain possible future scenarios that scientists actively study and monitor.
Megatsunamis represent a particularly dramatic threat, dwarfing regular tsunami waves. While typical tsunamis might reach heights of 30 feet, megatsunamis can tower over 100 feet tall. The most dramatic example in recent geological history occurred 66 million years ago when the Chicxulub asteroid impact generated waves possibly reaching heights of several thousand feet. More recently, in 1958, Alaska’s Lituya Bay experienced a megatsunami reaching 1,720 feet – the highest wave ever recorded – when a magnitude 7.8 earthquake triggered a massive landslide.
The 2004 Indian Ocean tsunami, while devastating with waves up to 100 feet high and causing over 230,000 deaths across multiple countries, pales in comparison to true megatsunamis. This event, triggered by a magnitude 9.1 earthquake, demonstrates the destructive power of “conventional” tsunamis, but megatsunamis operate on an entirely different scale.
The 1958 Lituya Bay megatsunami in Alaska remains the benchmark for these extreme events. When a magnitude 7.8 earthquake triggered a massive landslide, 90 million tons of rock plunged into the narrow bay. The resulting wave stripped vegetation off slopes up to 1,720 feet high – more than three times the height of the Washington Monument. Remarkably, despite its immense power, the wave’s effects were largely contained within the bay’s unique geography.
However, scientists are particularly concerned about the Cumbre Vieja volcano in La Palma, Canary Islands. Studies suggest that a massive flank collapse of this volcano could trigger a megatsunami affecting the entire Atlantic Basin, including the eastern seaboard of the United States and canada. Models indicate that such an event could generate initial waves over 3,000 feet high, which, while diminishing over distance, could still reach the American East Coast with heights of 15-25 meters (50-80 feet). Cities from Miami to Boston could face devastating impacts hours after the initial collapse. While some researchers debate the likelihood and potential scale of such an event, the geological evidence of previous collapses in the Canary Islands suggests this scenario deserves serious consideration in long-term disaster planning.
So-called “supervolcanoes” pose an even more comprehensive global threat. These massive volcanic systems, like Yellowstone in Wyoming or Toba in Indonesia, contain magma chambers many times larger than conventional volcanoes. The last super-eruption occurred approximately 26,500 years ago at Lake Taupo, New Zealand. A Yellowstone super-eruption would eject thousands of cubic kilometers of ash into the atmosphere, potentially triggering a “volcanic winter” lasting several years. The resulting climate disruption could devastate global agriculture and ecosystems. The 1991 eruption of Mount Pinatubo, in the Philippines, which destroyed Clark Air Base, lowered global temperatures by an estimated 0.5°C.
But Pinatubo was small compared to Tambora. The Mount Tambora eruption of 1815, in modern day Indonesia was so massive, it caused the “Year Without A Summer“, in 1816. Global temperatures dropped almost a full degree in Fahrenheit. Among the effects, were near-total crop failures across the globe, leading to the last time widespread famine was observed in North America.
Modern supervolcano monitoring has revealed these sleeping giants are far more dynamic than previously thought. Yellowstone’s massive magma chamber “breathes,” causing the ground to rise and fall by several inches over decades. These movements, while fascinating to scientists, often trigger public anxiety about an imminent eruption – fears that experts generally consider premature.
The last truly massive super-eruption transformed global climate during the Stone Age. Indonesia’s Toba volcano erupted approximately 74,000 years ago, ejecting an estimated 2,800 cubic kilometers of material – enough to cover the state of Texas in 15 feet of ash. Some researchers suggest this event created a global volcanic winter that may have reduced the early human population to just a few thousand individuals, though this hypothesis remains debated.
Today, there are about 20 known supervolcanoes worldwide. Besides Yellowstone, significant ones include California’s Long Valley Caldera, New Zealand’s Taupo Volcanic Zone, and Bolivia’s Cerro Galan. Each presents unique monitoring challenges. The Campi Flegrei supervolcano near Naples, Italy, poses particular concern due to its location near a major metropolitan area. Recent ground deformation there has led authorities to raise alert levels, though immediate danger remains low. Scientists emphasize that supervolcano systems typically provide warning signs months or years before major eruptions.
But perhaps the most dramatic potential megadisaster comes from space. Large asteroid impacts, like the Chicxulub event that contributed to the dinosaurs’ extinction, can fundamentally alter Earth’s climate and ecosystems. The Chicxulub impactor, estimated at 6-10 miles wide, released energy equivalent to 10 billion Hiroshima bombs. The impact created a crater 93 miles wide and triggered global wildfires, acid rain, and years of darkness from atmospheric debris.
The threat of cosmic impacts moved from scientific theory to witnessed reality during the 2013 Chelyabinsk event in Russia. The meteor, only about 20 meters across, exploded in an air burst with the force of roughly 400-500 kilotons of TNT, damaging thousands of buildings and injuring about 1,500 people. Most injuries came from broken glass as the shock wave blew out windows across the region. Remarkably, this relatively small object released energy equivalent to about 26-33 Hiroshima bombs.
Arizona’s Barringer Meteor Crater stands as America’s best-preserved impact site, offering crucial insights into cosmic collisions. Created approximately 50,000 years ago by a nickel-iron meteor only about 160 feet across, the crater’s nearly mile-wide diameter demonstrates the immense energy released in even moderate impacts. The meteor struck with the force of about 10 megatons of TNT, equivalent to a significant thermonuclear weapon.
The Burckle Impact Event, believed to have occurred around 3000 BCE in the Indian Ocean, may represent a crucial link between cosmic impacts and human history. Some researchers suggest this oceanic impact could have generated massive tsunamis affecting early civilizations, potentially inspiring various flood myths found in multiple cultures’ histories. While controversial, this theory highlights how impacts might have influenced human development.
The 1994 collision of Comet Shoemaker-Levy 9 with Jupiter provided scientists their first opportunity to observe a major impact in real-time. The fragmented comet’s pieces, some over a mile wide, slammed into Jupiter over several days, creating Earth-sized dark spots in the gas giant’s atmosphere. This event served as a cosmic wake-up call, demonstrating that large impacts aren’t merely historical events but ongoing phenomena in our solar system.
These various events highlight different aspects of the impact threat: Chelyabinsk showed how even relatively small objects can cause significant damage, Barringer demonstrates the long-lasting evidence of impact events, Burckle suggests potential historical implications, and Shoemaker-Levy 9 proved that large impacts continue to occur in our cosmic neighborhood. Modern detection systems now track over 95% of potentially hazardous asteroids larger than 1 kilometer, but smaller objects – still capable of causing regional devastation – remain more difficult to catalog comprehensively.
Modern science provides both warning systems and potential mitigation strategies for these threats. NASA’s Planetary Defense Coordination Office actively tracks potentially hazardous asteroids. The DART mission in 2022 successfully demonstrated humanity’s ability to alter an asteroid’s trajectory. Volcanic observatories worldwide monitor supervolcano systems using seismic networks, ground deformation measurements, and gas emissions analysis. Coastal regions increasingly incorporate megatsunami scenarios into their disaster planning.
However, these events remain statistically rare. The odds of a civilization-threatening impact in any given century are estimated at less than 0.01%. Supervolcano eruptions occur on timescales of hundreds of thousands of years. Still, understanding these phenomena helps contextualize humanity’s place in Earth’s broader history and highlights the importance of maintaining technological capabilities that might help prevent or mitigate such disasters.
That said, these threats are always a possibility. And chances are very good that when they do happen, you are likely going to survive…initially, at least. As the recent disasters of Hurricane Helene and the fires that have incinerated large swaths of the Los Angeles Basin have demonstrated, you are on your own. Government might eventually get to you, and your family, friends and neighbors might make it, as well, but they are likely to be in the same condition as you – you need a plan. It is neither paranoid nor silly to take precautions, whether with supplies, an evacuation plan or both.
As in most things in the human experience, you are on your own. Make a decision on your future for something other than your finances.
