Tsunami!

Huge ocean waves tsunamis

It’s a killer club song by DVBBS & Borgeous and it’s coming to a Pacific neighbourhood near you to totally ruin your day.

Tsunami!

Tsunamis are big waves… the result of a monumental displacement of water that usually takes place at depth somewhere on the ocean floor, although they can also be caused in large lakes and by seismic events occurring at or near the Earth’s surface. The result is a colossal series of waves that only the most baked of surfers would attempt to tackle. The damage is potentially staggering should these waves make landfall and they frequently do.

Makin’ Waves: A How To Guide

fat-man-jumping-in-a-pool

As it was mentioned, tsunamis are most often caused by events that have the energy to displace enough water to give the coastlines of the adjacent continents a salt-water enema. What kind of events might these be?

  • Earthquakes, the result of a sudden and violent wrenching of Earth’s foundations, can kick the water up and around its epicentre into violent protest.
  • Fat celebrities jumping off their gazillion dollar luxury yachts.
  • Landslides can send many tonnes of rock and debris crashing into water, generating large waves that can wipe out beaches, forests and any and all human habitation.
  • Iceberg calving does the same as landslides, except, instead of earth and rock, it sends mammoth-sized chunks of ice and snow (and perhaps the occasional cryogenically preserved mammoth) careening into the ocean.
  • Volcanic eruptions can do both: they can cause incredible landslides of debris into the ocean or a lake and they can cause tremors and earthquakes violent enough to generate tsunamis.

And then there are meteorite strikes that can cause the kind of giant waves portrayed in end-of-the-world movies The Day After Tomorrow and Deep Impact. Even the detonation of nuclear bombs (refer to the totes adorbs film Finding Nemo) can cause billions of litres of previously peaceful water to relocate to your previously peaceful neighbourhood.

Mother Nature Can Be A Real Jerk

Japanese tsunami earthquake 2011
You’d be forgiven for believing this image to have been grossly photo-shopped. To the best of my knowledge it hasn’t been and you can find more incredible photos of the tsunami that inundated the Japanese coastline in March 2011 here: National Geographic News 

Yes, she can. You see, tsunamis – natural disasters in their own right – are typically conceived by natural disasters. As if an earthquake wasn’t enough to rattle your nerves, here comes a solid wall of water and debris to thoroughly spoil your day. This makes them the coarse salt in the wound of the earthquake stricken city – as the Pacific coastline of Japan tragically experienced in March 2011 – and they add insult to injury to anyone who has managed to claw their way through one natural disaster only to encounter another.

Japanese tsunami earthquake 2011
Photo Credit: BBC News

Tsunami means “Harbour Wave” in Japanese and the etymology (“word origin” for the vocabulary handicapped) is brilliant…

Japanese fishermen would climb into their creaky little fishing boats and spend the day out on the swell catching fish as fishermen in fishing boats do. Without noticing anything unusual at all, they’d return to the harbour with their soon-to-be sushi only to find their entire village looking particularly soggy and sorry for itself. And so, tsunamis became known as “Harbour Waves” because they didn’t seem to happen anywhere else.

But, how had something as conspicuous as a giant wave escaped their notice? Surely, the wall of water that is a tsunami would have flung the fishermen and their creaky little fishing boats into an abyssal wave trough before crashing ashore?

The answer would be “not necessarily” and here’s why…

Tsunami Travel

Tsunamis are ocean waves, which means that they travel in a waveform and are governed by the same physical parameters and laws. They have wavelength (λ), which is the distance between the trough and the crest of the wave (refer to graph below); and amplitude (a), the distance from the ocean’s resting point to top of the crest.

waveform physics
If this diagram starts to disinter excruciating memories of Grade 11 trigonometry, bury the anxiety underneath the rubble of your other psychological baggage. It’s just an ocean wave. Nothing more.

In addition to having a wavelength and amplitude, ocean waves travel at a certain speed (ν) and with a certain amount of energy (E). People who study physical oceanography make use of all kinds of fancy looking equations to calculate these various parameters given one thing or another. I used to be very well-versed in these equations, since I majored in ocean and atmospheric science back at university. Since those distant book-bound days, however, an abundance of beer, travel and floozies has done its damnedest to erase my memory of these equations and replace them with sweeter recollections. So, I won’t subject you or myself to any math. Rather, I will explain in concept how physical parameters such as energy and wave speed affect wave size, which is something you’re going to WANT to know if your day on the beach takes an unexpected turn for the disastrous.

2004 Thailand tsunami

Photo Credit: Asian Tsunami Video

Wave Shoaling

Water may travel in waves on the open sea, but each wave is in turn composed of hoards of molecules. So while we see ocean waves as a surface oscillation (an up and then down motion of the water) beneath the surface, the composite water molecules are tracing quite different paths. Water molecules in a wave travel in great ellipses, or circles. The molecules closest to the water’s surface have the most fun on the merry-go-round, which you can see in the diagram below, while those at the bottom, nearest to the ocean floor are seriously considering asking for a refund.

wave shoaling

Photo Credit: The COMET Program

When a wave is far out at sea where the ocean floor lies many thousands of metres away from the surface, these particle motions are hidden beneath the water and are felt at the surface as a swell. Regular ocean waves or “wind waves” with a garden-variety wavelength of 30 to 40 metres (100 to 130 ft.) are experienced as the kind of rolling up-down motion that can turn you green around the gills if you have a delicate constitution.

Tsunamis, on the other hand, have such a large wavelength that for hundreds of kilometres the water would almost seem to go still as you ride up the side of a very long, yet shallow swell, which belies the presence of the roiling monster passing beneath your very feet. Out at sea, thankfully, you’re none the wiser and also totally safe. On shore, however, things are about to get super soggy.

bodhi tree flood

As a wave travels towards land, the sea bottom rises to meet the continental shelf and then the actual shore. The shallower water slows down or decreases the velocity of the incoming waves. What doesn’t change is the amount of energy the wave is carrying. Think about it: energy IS speed. The faster you run, the more energy you burn. By comparison, relinquishing your hung-over self to the sweet oblivion of your couch requires hardly any energy at all.

Unlike your body, however, waves travelling towards the shore may slow down as they breach shallower depths, but the amount of energy contained by their infinite composite particles remains the same. It’s like running a marathon even though you’re facedown in your couch. Oh look! A quarter!

What does this all mean? Well, if a wave isn’t spending all that energy on travelling fast and yet its energy remains the same when it slows down, where the hell does it all go?

The answer is UP!

up_movie_balloons_house-wide

So, as a wave approaches the shore, it slows down and compensates by increasing in height. It then becomes visible above the surface of the ocean as rolling, tumbling water… the kind that stringy haired, gnarly Californians like to surf. Wave shoaling essentially explains this process. It’s how those great undulating swells you experience out on the open ocean turn into breaking waves on the shore.

As tsunamis hit shallower water, the seafloor rears up to become dry land and the entire monstrous size of the wave is revealed. It’s owing to the vast wavelengths (and small amplitudes) of these giant waves that they go by completely unnoticed on the open ocean by those Japanese fishermen. All that they would have felt was a slight sea swell, which would be virtually indistinguishable from any of the other swells they had been sitting on all day long. However, the up-to-200km wavelength of the tsunami and its arrival in shallower waters results in the sudden and eerie recess of the sea – like an anomalous low tide – only to bring it crashing back in a surge of super “high tide” that’s so swift and violent, beach goers have only seconds to plan their exit strategies. If there are palm trees nearby, make sure you pick a sturdy one.

You might be there awhile.

Tsunami Statistics (Say That Three Times Fast)

Desert Island Coastline After Tsunami, Banyak Archipelago

The December 2004 Indian Ocean tsunami that famously struck a number of Thailand’s popular resort towns was generated by a 9.2 magnitude earthquake and killed more than 230,000 people in 14 countries bordering the ocean. Over two million people were negatively affected by this tsunami with the greatest number of deaths being recorded in Indonesia (165,708). The estimated cost of the damage done to countries from Indonesia, Thailand and Myanmar to Sri-Lanka, Kenya and Somalia was $15 billion according to the Disaster Prevention Organization.

The March 2011 Pacific Ocean tsunami that struck Tokyo, Japan, was caused by a 9.0 magnitude earthquake – the largest to have affected Japan on record. The tsunami that made landfall on the 11th of the month reached over 9 metres (30 ft.) in height and caused $300 billion worth of material damage. It also claimed the lives of 15,884 people, according to CNN.com, which is not hard to believe when you take a look at some of the spectacular images to have been published after this disaster.

Class Dismissed: Your Take-Home Message 

Japanese tsunami earthquake 2011

Tsunamis are big waves caused by the voluminous displacement of water via earthquakes, meteor strikes, iceberg calving, nuclear explosion, landslides, volcanic eruptions and Kirstie Alley at the beach during the nadir of her yo-yo dieting. Tsunamis are one cataclysmic event born from another and for this reason, they are devastating and yet deceptive, because we only know about them when they make landfall.

Owing to their unpredictable nature, they are (surprise) hard to predict and not all tsunami warnings culminate in a tsunami. Likewise, there could be no warning at all and you could find your pacific island holiday rudely interrupted. As with all natural disasters, however, they serve as needed reminders that we are by no means the most powerful force at work on this planet, nor will we ever be.

Huge wave tsunami

Queen and Quantum Mechanics

I’ve had quite a few readers ask me to explain String Theory to them in a way that is understandable to those without an advanced science degree in Physics. Until now I haven’t been able to think of an appropriate way to do so, quite simply because I don’t understand the darn thing myself.

Thankfully, A Cappella Science has put together a BRILLIANT and amazing science video that explains it all and it doesn’t even matter if you still don’t understand String Theory afterwards, because the lyrical manipulation and music is so damn good, nobody cares! Anything performed to the tune of Bohemian Rhapsody is entertaining.

So, whoever told you the mash-up of Green Day’s “Boulevard of Broken Dreams” and Oasis’ “Wonderwall” was the best that’s ever been done: they were lying and here’s why…

Video Source: Uploaded by A Cappella Science to YouTube Channel https://www.youtube.com/channel/UCTev4RNBiu6lqtx8z1e87fQ

Today's Sciencey LOL

Say it’s true!!

Funny science Emma Watson

Quantum physics is an established field of science that has revealed to us crucial insights into the behaviour of our physical environment and those that lie beyond the boundaries of our observable universe. As such, we can all look forward to the eventuality of banging Emma Watson. And if Hermoine Granger isn’t up your alley, or you don’t want her there, then you can always apply this probability to your favorite sexy celebrity.

That certainly is awesome.

TED Talks with Mythbusters' Adam Savage

Adam Savage is one half of the insane genius behind the hit TV show Mythbusters and in this illuminating short TED Talk, he explains to us how some of history’s most profound discoveries have come from really simple, yet insightful methods: Eratosthenes’ calculation of the Earth’s circumference (200 BC) and Fizeau’s measurement of the speed of light (1849).

It’s a lesson in how you don’t have to have a PHD behind your name to conceive mighty concepts.

Amazing Science Video Source: “How simple ideas lead to scientific discoveries” – TED Talks. Uploaded by TED-Ed on YouTube channel https://youtu.be/F8UFGu2M2gM

View full lesson: http://ed.ted.com/lessons/how-simple-…

Today's Sciencey LOL

Funny science picture

According to Newton’s First Law of Motion, an object will continue moving at the same speed and in the same direction unless acted upon by another/external force. What this means is when you slam the brakes on your 18-wheeler truck to avoid a family of rednecks crossing the road, your massive cargo of solid rock will continue to travel forward at speed.

Guess you should have strapped that in, mate! Or not… your picture has officially gone viral and has provided millions of science students with a perfect way to never forget what Newton’s First Law of Motion is.

Newton’s Laws of Motion and the Pedestrians of Woodstock Main Road

Science education in this country is appalling. Clearly, from the lay person’s complete contempt for the fundamental work of Sir Isaac Newton, mechanical physicist extraordinaire. But before I drop any bigger and more incomprehensible words like ‘incomprehensible,’ let’s shut our eyes and take a visual journey down Woodstock Main Road.

You may want to open them again. You know, to read on…

Woodstock Main Road: A Visual Journey Through an Historic Suburb

Woodstock Main Road is a hubbub of activity. Furniture stores (of the used variety), clothing stores (of the hand-me-down variety), shoe shops (of the sweat-shop produced variety) and antique shops (of the I-got-screwed-in-my-grandmother’s-will variety) line both sides of this well-travelled route through one of Cape Town’s most historic suburbs. Woodstock is a fantastic place to live, if, of course, the lock on your gate on your 3-metre high industrial steel electrified fence is working. It has a real vibrancy about it, with its red brick-faced buildings, colourful graffiti, the pervasive smell of KFC, open air fruit and vegetable stands, incessant hooting and blood curdling cries of Caaype Teeeeeaaaawwwn!! If Cape Town was a flesh-and-blood organ, Woodstock Main Road would be a pulsating artery complete with white and black blood cells.

As with any congested roadway in Cape Town, your average code B licensed vehicle driver has quite a challenge on his or her hands. Taxis regularly risk people’s lives getting them to and from work every day, while bus drivers exploit the incredible size of their vehicles and low wage rage to literally intimidate other cars off the road. But it’s not the irresponsible bus drivers that make me want to pull a 12-guage shot gun out from under my car seat. It’s not the taxi drivers that make me wish I could explode their engines with bolts of pure energy from my eyes (okay, maybe a little…)

No. It’s the pedestrians of Woodstock Main Road and their sheer lack of respect for Newton’s Three Laws of Motion that really make me homicidal. Try it. I dare you. Try and drive the length of Woodstock Main Road without having at least three cardiac arrests. People… just… walk. They don’t care. They just walk across the road without looking. There have been at least 27 occasions that I have wanted to slam my foot down (oops officer, sorry, wrong pedal!) and mow down a pedestrian who, in a demonstration of complete faith reminiscent of Indiana Jones walking across that invisible bridge in The Last Crusade, just crosses the road without looking. And they don’t walk… they stroll. They epitomize the meaning of the word ‘perambulate’:

“Let’s take a leisurely perambulation across this busy road, Geraldine.”

“Why yes Ashwell, I think I could do with a leisurely perambulation across this busy road after that rather rich lunch of vis en slap tjips!”

South Africa: A Country Crying Out for Physics Education

As I said, there have been at least 27 occasions on which I’ve wanted to make chunky kibbles out of the special breed of idiot that perambulates across Woodstock Main Road. But then, on the 28th occasion, or 29th (who’s counting?), I came to a blinding realisation… a revelation of neutron star gravity.

Science education in this country sucks. Clearly.

These people know NOTHING of Newton’s Three Laws of Motion. Of course! Why didn’t I see this before? If they had any idea what a 1,000 kg body travelling at 60km/hr was capable of doing to an essentially stationary 80 kg body, they would probably look both ways before illegally strolling across the road. They would actually probably look left and then right AND THEN LEFT AGAIN, if they knew what kind of party those opposing forces would throw right there in the middle of the road. There would be doef-doef music. And red streamers.

So, in order to remedy this situation and to allow minibus taxis to regain the title of “Most Hateful Moving Object on the Road,” I have decided to explain to Cape Town exactly what Newton’s Three Laws of Motion are in a way that you all will most definitely understand.

Newton’s Three Laws of Motion Demystified

The Surprisingly Sexy Sir Isaac Newton

Sir Isaac Newton was a physicist who pioneered the field of mechanical physics. He took the whole idea of motion, of movement, and put words and equations to it. And he did this by coming up with three iron-clad rules: three immutable laws that would forevermore govern motion, not just on this planet, but (insofar as we can tell) in the entire Universe. Wherever you are in the world, or indeed the galaxy, you can be sure that these rules will apply to you. If you don’t believe me, run in front of a bus in Italy. Repeat on Jupiter.

Sucks every time.

Newton’s First Law:

[In fancy speak: Every object continues in its state of rest, or of uniform motion in a straight line, unless compelled to change that state by external forces acted upon it.]

In South African English: If I’m travelling down Woodstock Main road at a constant speed, I will continue to do so unless a taxi T-bones me (see Fig. 1).

Fig. 1: Series of Scientific Diagrams Demonstrating Newton’s First Law of Motion

Newton’s Second Law:

[In fancy speak: The acceleration of a body (a) is directly proportional to the net force (F) acting on it and inversely proportional to the mass (m) of the body. I.e. F = m.a]

In South African English: The force (F) my car would exert upon you, the pedestrian, can be calculated by multiplying the mass of my car by my acceleration. Conversely, the acceleration of your body through the air when I hit you with my car can be calculated by dividing the force my car exerts on you by your mass (see image 2).

In plainer South African English: My car would bliksem you to pieces, broo!

Fig. 2: Series of Scientific Diagrams Demonstrating Newton’s Second Law of Motion

Newton’s Third Law

[In fancy speak: For every action, there is an equal and opposite reaction.]

In South African English: If I hit you with my car, you will exert a force on my car just as my car would exert a force on you. But, according to Newton’s Second Law of Motion, my car would win (refer to image 2).

Class Dismissed: Your Take-Home Message

These are the three immutable laws of physical motion. Remember them well the next time you think a belligerent stare will be sufficient to slow down my car. Remember that the next time you make me burn rubber or swerve into oncoming traffic to avoid manslaughter charges.

Please people, let’s give the minibus taxi back its rightful title as “Most Hateful Moving Object on the Road” and look both ways next time you leisurely perambulate across a busy road.