10 Ways the Earth Is Trying to Kill You

Living near a volcano is sort of like living in a bad neighborhood. A really, really, really bad neighborhood where you have to sleep with one eye open and look over your shoulder everywhere you go. Because volcanoes wield a multitude of ways to kill you.

For each year of the 20th century, volcanoes killed more than 800 people. In recorded history, volcanoes have snuffed out the lives of roughly a quarter of a million humans, although that number could be much higher.

Red-hot, glowing lava is a volcano's signature showstopper, but it's also too slow to be very deadly. You're more likely to be felled by pyroclastic flows, which burst from the Earth's innards as a combination of hot gases, mud and rock, hurling down a mountain at hundreds of miles per hour.

Although they're far less spectacular, invisible poisonous gases are another real danger. When released from volcanos, these gases can swiftly overwhelm entire communities, killing every living creature.

Volcanoes also eject massive rocks that squash people and buildings. Even if it's the size of a house, you probably won't see that big boulder before it hits you.

Finally, volcanoes can spew tons of rock ash, which looks light and fluffy but is actually finely ground rock. A few inches of compacted ash can crush buildings and cars, and just as awfully, it can kill endless acres of crops, make transportation impossible and grind entire cities to a halt.

The shifting of tectonic plates often causes shuddering and shaking of the Earth's crust, particularly in areas near active fault lines like those in California. Japan, which rests on the notorious "Ring of Fire" fault line, experiences more than 2,000 tremors every single year.

Earthquakes may be so mild that only sophisticated instruments detect them. Or they can be so powerful that they violently shake the ground, causing everything from soil to cement to ripple like waves on a pond, tearing huge gashes in what was a seemingly solid surface only moments earlier.

Yet earthquakes alone aren't typically what kill people — instead, collapsing buildings crush, trap and suffocate you. When this happens in heavily populated areas, tens of thousands of people may die.

In January 2010, a magnitude 7.0 quake struck Haiti, a poor country with many ramshackle buildings. After the dust had settled, more than 200,000 people were dead. Some estimates topped 300,000, making it one of the deadliest earthquakes in history.

Even if you live an in area where construction is meant to withstand earthquakes, you probably don't want to be around when one hits. Our best building materials can only take so much abuse before they crumble under the might of a tectonic shift.

If the ocean waves begin to recede unexpectedly, says the folklore, head for high ground. That disappearing water can mean that a tsunami is on its way. Tsunamis are waves that can be caused by landslides and volcanic eruptions, but they're most famously spawned by underwater earthquakes. The shaking pushes the water to and fro, and the ripple effect causes waves that may travel hundreds or even thousands of miles.

Tsunamis can be dozens of feet tall, but in deep water, the waves may not be apparent on the surface. When these waves approach land, the upper portion of the waves is faster on the move than the lower portion. Then massive water walls crash into (and over) seawalls and entire cities with the violence of a flash flood combined with the power of several raging rivers. Concrete buildings may survive ... or they may crumble beneath the water's force. Your only real hope of survival is high ground.

In 2004, an earthquake of around magnitude 9.1 occurred in the Indian Ocean near Sumatra. The resulting tsunami affected 14 countries and blasted some with waves nearly 100 feet (30 meters) tall. Unrelenting water scoured entire towns, pushing buildings as though they were toys and drowning tens of thousands of people. When the waters finally dried, more than 230,000 people were dead, making this one of the worst natural disasters in human history.

As if the harrowing violence of earthquakes and tsunamis wasn't enough, the Earth is also trying to sneak up on you to kill you silently and quickly. That's right, Mother Earth is trying to smother you with poisonous gas, and she'll use the cover of a friendly looking lake to disguise her intentions.

In Africa there are a number of lakes that rest in old volcano craters. Many miles below the surface, hot magma pushes gases such as carbon dioxide upward to the lake bottoms. In most geographical areas, lakes encounter enough mild day-to-day turmoil that the water and gases mix regularly, causing harmful gases to release slowly and safely into the air.

But some lakes, particularly those in the tropics, are relatively still, and the gas collects in large volumes. The unmoving water traps those gases until the pressure finally gives way in an enormous rush to the surface. As carbon dioxide gushes, it forms an invisible cloud that can travel miles from the lake, suffocating any creature its path.

In 1986, just such a cloud killed around 1,700 people in Cameroon. These kind of disasters may not be spectacular, but under the right circumstances they're as deadly and insidious as any dangers Earth wields.

Torrential rains are a curse for humankind. They cause flash floods that wash away fields and roads and sometimes even people. But there's something even more ominous afoot when dozens of largemouth bass suddenly fall from the heavens.

The technical term for random things falling from the sky is non-aqueous rain, and as the name implies, it can refer to any non-water objects that plop to earth. Non-aqueous rain has a long history — in the Book of Exodus, one of the plagues that afflicted Egypt included a storm of frogs. In 2007, a storm of worms fell in Louisiana. In mass media and in folklore, there are innumerable reports of animal rains including fish, spiders, jellyfish, birds, frogs, toads and other small creatures.

Scientists aren't sure how this phenomenon is possible. They speculate that at least some of these so-called rains, such as worms and snakes, are actually the result of unusual flooding carrying this surprising debris onto land, and nothing actually falls from the sky. In cases where people actually witness animals falling from the big blue, researchers say it's possible that waterspouts or powerful updrafts could snatch groups of animals and then deposit them miles away.

Still, these kinds of animal rains have happened in areas where no wild winds were reported at all. These are just the perplexing kinds of things that happen when your home planet is constantly attempting to do away with you.

The Japanese call them dragon twists. Hollywood types might prefer something flashier, like "firenado." But no matter the name, fire tornadoes are among the most visually stunning ways that Earth is trying to send you into the great beyond.

Fire tornadoes happen when small vortices are paired with a ground fire. Swirling vortices occur when hot rising air crashes into areas of cooler, low pressure air. These situations cause dust devils, which are basically smaller and much less dangerous versions of tornadoes.

However, when you pair a dust devil with a fire, things get serious in a hurry. The flames will actually swirl upward, creating a spinning funnel of flame that can scorch anything (or anyone) that happens to be nearby. Compared to full-blown tornadoes, dragon twists are smaller, but they're fast and can quickly change directions. Nearby buildings or vehicles may ignite, causing all sorts of perilous situations for civilians and first responders alike.

Swine flu, smallpox, bird flu, plague, HIV. These are among the most frightening and uncontrollable means that Earth is using to kill all of us. Sometimes our medicines and countermeasures ward off disease. Other times, microbes get the upper hand, infecting and killing millions of people in a matter of years in what's called a pandemic, a disease that infects people across a huge geographical area.

The Black Death was one of the most infamous pandemics in history. In 1347, it spread from China to Europe via trade ships. Dying sailors were stricken with the black boils that gave the disease its awful name. Caused by an airborne bacteria, it spread at a breakneck pace around the world, and it hit Europe harder than anywhere else.

By some estimates, the bacteria wiped out around 200 million in just a couple of years. Lower estimates are still staggering, at roughly 75 million. There are estimates that indicate that 60 percent of London's the population was killed by the Black Death.

The Black Death is simply one example of a pandemic. There have been others, like the 1918 Spanish Flu that killed around 200,000, or the HIV outbreak, which is ongoing and has killed perhaps 25 million people. It's further proof that the smallest enemies are sometimes the worst.

When it comes to thinning the human herd, heat is one of the most effective killers on the planet. It's quiet and it's sneaky, with its death tolls often going nearly unnoticed until the worst of the sultriness has passed.

Centuries ago, we humans hid in the shadows to escape long-lasting summer heat waves. In these more modern times, we shield ourselves with buildings and blasts of air-conditioning units. But the sun has a way of making our contemporary technologies look weak and powerless.

In 2003, a three-week heat wave hung over Europe. Power companies couldn't supply enough energy to keep up with the demand for air conditioners. Utility lines simply melted. The heat began to rise in apartments and offices across the continent, and the results were catastrophic.

Elderly people with poor mobility, higher levels of poverty and poorer health began dying in droves. If they had air conditioning at all, their units failed in the scorching heat and then they perished in their stifling residences. Officials found more than 15,000 people just in Paris, and across Europe the death toll was around 70,000 [source: Gannon].

Heat kills by stressing your body to the breaking point, raising your heart rate and respiration and then often triggering secondary effects such as heart attack or stroke. Once your body temperature shoots past 104 degrees Fahrenheit (40 degrees Celsius), you'll have a harder time recovering. This is especially true for older people. After days or weeks of high heat, these vulnerable populations die quickly, all thanks to awful, ceaseless heat exposure.

Hurricanes are godlike bringers of death. They hover on the horizon for days, slowly approaching land with inescapable, ominous fury. Sometimes they'll veer off at the last moment, sparing entire countries. Other times they'll smash directly into major towns and cities, causing misery in a multitude of ways.

High winds rip smaller buildings apart, creating wicked shrapnel that pierces and bashes everything in sight. Sheets of rain flood homes in a matter of hours or even minutes. High surges of water pushed ahead of the storm inundate populated areas in a manner resembling tsunamis. A hurricane hitting land can bring an unstoppable wall of water that shoves and grinds and drowns everything around it.

In 1926, the Great Miami hurricane, a Category 4 storm, hit Miami with storm surges nearly 12 feet (3.7 meters) high. In today's dollars, the storm caused a whopping $157 billion in damages and killed almost 400 people.

Yet that Miami debacle is nothing when compared to the 1970 Bhola cyclone that landed in Bangladesh. With winds of more than 115 miles per hour, the hurricane whipped such a frenzy that its storm surge killed up to half a million people, making it one of the deadliest natural disasters ever [source: HurricaneScience].

Parasites are creatures that exploit another creature — the host — for food, shelter or protection. Sometimes parasites are fairly innocuous. For example, you probably have some intestinal protozoa flailing around in your guts right now that are feeding off of your breakfast, but those little guys most likely aren't going to make you sick.

Then there's the Loa loa worm, which is native to wet areas of West Africa. Spread by fly bites, the worm courses beneath your skin and can wiggle its way into your eyes. If your friends peer closely enough they'll actually be able to see your little parasite writhing around, and you'll be able to feel it, too. Horrifying? Yes. But the Loa loa isn't alone.

All told, there may be around 100 or so parasites built specifically to latch onto humans. That doesn't really capture the whole story, though. Some researchers estimate that most creatures on Earth probably exhibit parasitic behavior at some point in their lifecycles, and that this kind of activity is actually necessary to keep ecosystems working properly. Dog eat dog world, indeed.

If parasitism is an integral part of life on Earth, what exactly does that say about our lives on this planet? Earth may be our life raft in an ocean of universal vastness and uncertainty, but it is far from a benign and friendly place. From volcanoes to venomous snakes to jarring earthquakes, our home world is a place loaded with danger in every nook and cranny. Be safe out there — our Earth is trying to kill you.