A tsunami is a group of waves associated with sudden disturbances in a body of water. They've been happening since the Earth had water, already killed more than 230,000 people this century, and are terrifyingly awesome.

An earthquake may or may not be felt, but what comes next is the same either way.

Figure 1: Water did this. Alaska 1964

Just The Facts

  1. Tsunami (literally Tsu wave) is Japanese for "tidal wave". People here used to call them tidal waves too, until we learned Japan had one word to describe the same thing.
  2. Since tsunami (as we'll see) are random occurences, we can start using the term tidal wave to describe waves associated with tides. (Which are not random at all.)
  3. A tsunami can be triggered by several causes and appear with or without warning, like diarrhea.
  4. Tsunamis occur as a result of major disruptions in large bodies of water, and travel faster the deeper it is.
  5. One tsunami is a group of waves, so don't think it's over after the first passes. Hell it may be the smallest.
  6. As complicated natural engines of death they aren't an easy topic to inject humor into, but we'll certainly try.
  7. That said it's worth noting, we won't be going into the kind of detail one might find in a textbook.

Undersea Earthquake Tsunami

You probably know an earthquake is what happens when the ground under our feet suddenly starts shaking. They can feel like the floor has transformed into a vibrating hotel bed or, if it's strong enough, a mechanical bull powered by Orly Taitz's boundless ignorance. Major earthquakes can displace the ground up or down by dozens of feet, along a fault for hundreds of miles. If this happens under the ocean, like it did on Christmas day* 2004 near Sumatra, a tsunami is created.

Local lush, trying to fix a minor uplift. Imagine this times five, underwater, minus him and the foliage.

People might think there's no problem so long as they don't feel an earthquake, and they'd be wrong since only a certain type of quake trigger tsunami, it's possible to have an undersea earthquake without** a tsunami. Also, earthquakes don't travel the distances a tsunami can: Thousands of miles, through deep ocean, over a period of hours at speeds equal to an average jetliner or great white shark. The Japanese didn't feel any shaking when, in 1700, the first waves to be called a tsunami hit them. Most likely because the quake happened offshore of what we now know as Washington state, about nine hours earlier.

Some countries now have floating sensors which can detect these long distance tsunamis, and actually provide a warning hours before the first wave hits. People near the quake and anyone living in areas without sensors will, of course, not be helped at all by them. We're sorry to be so blunt, but sugar coating probable certain death is just something we will not do. Nor will we clarify what the hell "probable certain" means.

For those close to a beach about to be hit, survival will rely mostly on luck. Depending upon which side of the displacement a person finds themselves on, there may be some warning of impending doom. One side goes up, the other down. In this case it's better to be on the downside because water will appear to be sucked out to sea, and stuff that's usually underwater, suddenly isn't anymore. This is actually the first wave's trough and it's nature telling anyone watching that a tsunami will arrive soon. People interested in survival should run inland and uphill.

Those who don't know what retreating water means might give in to curiosity, go walking around on the newly revealed beach, and get killed when the water returns. If you find yourself stuck with a loved one or friend who has no clue what's going on, refuses to flee, and you take time to convince them, please consider these as your last words:

"This is EXACTLY what Cracked said would happen if the water just up and left!! I totally deserve to be mentioned in the next section's intro for trying to save your dumb ass! Especially if we were in Alaska!!"

Just imagine the look on their face, as their brain tries its very best to comprehend both the coming water and that statement. Might be the last good laugh you'll ever have.

This would be one seriously hilarious picture, if these people weren't in mortal danger.

It's less complicated on the displacement's upside, where the crest appears first. People there get to see a wall of water suddenly heading their way, anyone caught in the open is pretty much screwed. Don't get us wrong, it's totally possible to survive, the same way it's possible for someone to eat a bullet and live. The chances are just pitifully small.

We can hear a few of you dismissing our warning anyway: "A wave, it's just water!", "Water doesn't scare me - I know how to swim!!", or "I'm Muper-fuckin-san, man!!!" The ability to not drown in calm water doesn't translate into surviving a tsunami, even especially if you're drunk. They are powerful waves pushing large rocks, heavy debris, and other people not smart enough to flee along with the water. Take a look at the immense amount of random crap, pictured below, you'll be "swimming" in. Still not convinced? Refer back to figure 1 and imagine the tire is actually your torso.

Probably Mai Tai vomit, used rubbers, raw sewage, and other stuff we try to avoid in there. Bet it smells great too.

*In Indonesia this happened on December 26, but slowpokes like us in the western hemisphere were still on December 25. If it'd of happened a day later, in the States it might have been known as the Great 2004 After Christmas Day Sale Tsunami.

**Do you know what a tsunami causing quake feels like? Neither do we, but if a tsunami is coming it'll be there soon, remember what we said about it moving as fast as a jet? If you are on or near a beach and feel an earthquake, you'll want to consider going as far inland as fast as possible. Ideally up a mountain or large hill, wait around 15/20 minutes before cautiously going back down and returning uphill at the first sign of a tsunami. Why? Is your life worth gambling with, so you can avoid a little physical exertion?

Landslide Tsunami

Alaska, for many reasons is a beautiful, but dangerous place. Especially for stupid people, Alaska can kill them in several unique ways. It's where one dude needlessly starved to death in an abandoned bus, on a hiking trail, less than 20 miles from a highway and small airport. In fact we've already sung his praises when he made numbero uno on one of our special lists. Another spent years "protecting" grizzly bears, presumably from hordes of pre-apocalypse poachers or zombies hungry for bear brains. One year their regular sources of food became especially scarce, so as the time for hibernation grew closer, bears looking to fatten up saw him more as an emergency food option than a protector.

In all fairness, neither guy had any possible way to know pursuing their dream would turn out so badly. Well, unless you count locals and rangers who tried talking them out of it, by citing the almost certain probability of these very outcomes. Alaska is a place which must be respected, beyond the obvious danger posed by bears and lack of food. There are also less conspicuous hazards, which can claim savvy residents and visitors just as easily.

Figure 2 (Despite what the original caption says)

USGS map from University of Wisconsin - Green Bay: Trim line after the megatsunami.

Such as the enormous landslide of July 10, 1958 which triggered waves like something out of a damn movie. It happened at an out of the way place called Lituya Bay, four people saw and survived one of the most awesome water related events witnessed by man. That's not hyperbole. There may have been larger waves witnessed by our illiterate ancestors, this was the biggest one ever recorded since we started writing stuff down.

An earthquake sent the highlighted area, near the Gilbert Inlet, sliding into the water, all at once. This was about 40 million cubic yards of rock falling from heights as much as 3000 feet. The resulting splash raced up the opposing slope as it stripped every tree in its path to a height of 1,700 feet. A tsunami appeared almost simultaneously, seeming to have emerged from the splash. This happened in less than a minute, but the "fun" had just begun. The wave took a few moments to actually reach the only survivors, and by then it was only around 50 - 75 feet high.

NOAA, the National Oceanic and Atmospheric Administration describes what happened as relayed by survivors: "They were sure they had seen the glacier riding high into sight from behind the western mountain, followed by a great wave of water washing over its steep face. During the following wild ride across the spit they believed they were 100 feet high, for there had been trees on the spit, and they were above them. They looked down on rocks as big as houses. They were incredulous and deeply thankful to be alive."

No pictures of either the tsunami or landslide exist, however we can see their result. Thanks to the United States Geological Survey we do have photos of the area both before and after:

Empty space

Head of Lituya Bay, August 1958

Same place, 1917. Trees used to extend down almost to the shore

Lituya Bay 1954

Four years later, note lighter areas of deforestation not visible in the 1954 photo

These kinds of things happen at Lituya Bay all the time, in the geologic sense of time. There were large tsunamis in 1854 and 1936, which is why the 1954 treeline pictured below, suddenly stops.

North shore of Lituya Bay, 1954 as seen from Cenotaph Island

Cenotaph Island and the north shore, top, in 1958

We don't want you to get the impression that landslide tsunamis are strictly local events, confined to small bays or fjords. Every now and then they can cross oceans, right now both coasts of North America are under the threat of two possible major landslides.

East of Spain lie a group of islands they know as Islas Canarias, we call 'em the Canary Islands. They are a lot like Hawaii, in that each island was created by a volcano. Since volcanoes are random piles of old lava, this makes them especially vulnerable to landslides. Some scientists think La Palma's western quarter could slide right off into the Atlantic, perhaps during a future eruption or earthquake. If this were to occur they theorize local tsunami up to 2,700 feet tall, with our east coast maybe seeing waves 1,000 feet high. We're not sure if they're right, but as far as possible disaster scenarios go, it's certainly more plausible than anything discussed here.

Oh yeah, almost forgot to mention the west coast hazard. Remember we said the Canarys are a lot like Hawaii? Well that's it, Hawaii, specifically the biggest island. Scientists who think La Palma could inundate the east coast cite a possibility the big Hawaiian island, called Hawaii, could do the same thing some day.

Don't freak out or anything, these deathwaves waiting to happen have been around since well before there was a United States. Unless you're new here, yo-oh shit, some of you probably are so we'll have to add a couple links. Anyway the rest of you probably remember we've already discussed how there are plenty of ways, some less likely than others, life could be snuffed out at any given moment.

Impact Tsunami

According to various edutainment shows, kid's textbooks and even NASA: A place called Chicxulub is where, sixty five million years ago, the dinosaurs met their Waterloo.* It was there that a huge rock, between 6 and 10 miles around, fell from space and landed in a shallow sea. Here's what NASA thinks happened:

Megatsunami? Hypertsunami? Ultratsunami? Jiggatsunami! No, not epic enough.

Did we say fell and landed? We actually meant crashed into and violently penetrated, yeah that's right, violently penetrated. Look, you know we trade in dick jokes, so it was just a matter of time before one popped up. Besides what else would you call plowing through not just the atmosphere, but a shallow sea** and generous amount of crust in less time than it took to read this sentence?

Sure, rocks that big are going to displace a lot of water no matter what, but this one was also moving about 64,000 feet per second (FPS) at impact. For some perspective on just how fast that is, let's compare it to the Navy's railgun:

It's fast enough that it ionizes air, like the Space Shuttle on re-entry, so it must be as fast as an asteroid right? We don't remember mentioning the shuttle, but even it isn't nearly as fast.*** And no, this slug is only going about 7,500 FPS, making it 56,500 short of even matching the 64,000 FPS our huge rock was moving at.

Water at the actual impact site would've become vapor and steam, H2O not close enough to be vaporized formed the tsunami depicted above. However these circumstances make the tsunami, ironically, a somewhat distant concern for anyone within a few hundred miles. First comes a wave of heat hot enough to ignite flesh, followed either by a mountain crumbling earthquake, rain of hot debris, or an airblast with the capability to separate limbs from torso. Anything surviving the purge just discussed, and believe us it'd be a miracle of luck, certainly won't live through the tsunami.

So many ways to die, it's kind of like what happened when that French archeologist opened the fancy box he stole from Indiana Jones. After an ancient special effects bonanza, his head exploded as the Nazi honchos flanking him had the flesh melted off their faces. Meanwhile chest and eyeball lightning shocked anyone watching, including a guy filming the proceedings. We wonder if anyone who watched the movie would be likewise smote. Only in this case everyone and everything is destroyed, people with their eyes closed, the island they're on, even the damn box.

*Turns out the Discovery Channel, textbooks, and NASA could be wrong about the whole dinosaur killing asteroid deal. Scientists have begun to find evidence that the Chicxulub impact happened around 3 million years before they went extinct. Don't take our word for it though, check out the article below.

**How shallow? Between 300 to 1800 feet or so, and if you don't think that's shallow then you should know the ocean can go down to like 22,000 feet. Not that 22,000 feet of water would've made much difference in a case like this.

***The shuttle goes approximatly 25,000 FPS at its fastest.

Volcano Tsunami

Before jumping right in to describe how they can cause a tsunami, some people reading this might need a quick description of volcanoes. Not you of course, we'd never second guess your knowledge, we mean other people. Volcanoes, by the way, are nothing but mountains made from old lava sitting on a huge chamber of magma slowly heading up to erupt. Sometimes the chamber empties during a major eruption, leaving nothing to hold up the volcanic mountain against gravity's relentless pull. Long story short, the mountain breaks into chunks of various sizes which fill the void created as magma becomes lava.* The resulting crater of mostly collapsed, old lava is what geologists call a caldera.

If this occurs on a volcanic island, surrounding water is drastically disrupted, creating a tsunami. Just like what happened on a little place, West of Java, called Krakatau in August, 1883. The tsunami which followed was 140 feet high, killed over 34,000 people, and went as far as 1 and a half miles inland. Oh yeah, you most likely know it as Krakatoa, probably because reports from 1883 screwed up the Portugese name Krakatao. Anyway, Indonesia, the country now controlling the area, calls it Krakatau. So we will too, since unlike Hollywood or Wikipedia, we're not faschole enough to tell people what they should call their islands. What is faschole? Our little way of combining "fascist" and "asshole" into one dynamic word.

Mt. Pinatubo's brand new caldera, early 1992. This volcano was about 1,000 feet taller a year earlier. Had that thousand feet been at or below sea level in the ocean - TSUNAMI!! See how it's collecting water? That's because it didn't cause a tsunami and wants to megaflood everyone. Or maybe, being a giant bowl, it tends to accumulate rainwater.

Scientists in 1883 figured the tsunami to have been caused by most of Krakatau Island just blowing the hell up. Not an unreasonable assumption, considering the eruption was audible for thousands** of miles. Except that we've since seen how volcanoes tend to collapse rather than explode. Like Mt. Pinatubo, which erupted on the same scale as Krakatau in 1991, literally. The Volcanic Explosivity Index measures how much new land is produced by an eruption on a numeric scale from 0 to 8, Krakatau and Mt. Pinatubo were level 6. The 1980 Mt. St. Helens eruption was only about 4 and a half.

There was also another level 6 eruption during the 20th century, in 1912, and it didn't blow up the erupting volcano either. If Mt. Pinatubo and Novarupta, the 1912 volcano, had been islands like Krakatau there would've been tsunamis too. Where are these volcanoes? Well, Mt. Pinatubo is in the Phillipines and Novarupta is in...


We really weren't bullshitting you about it being a dangerous place. Given the amount of attention Alaska has received here so far, it would be easy to throw in a bit about Sarah Palin. Well we won't. This is about awesome displays of disturbed water, not disturbingly stupid people who could someday be President. Holy shit! That's probably the scariest thing we've said yet.

*Magma and lava are the same thing, in different locations:

  • Magma = Lava under the Earth's surface
  • Lava = Magma on or above the Earth's surface, including underwater.

**Some scientists think it was so loud because during the collapse, water got into the magma chamber and flashed into steam as illustrated below by a Peter Gabriel fan .

Hot lava!