Tag: video

Tsunami

The tsunami spawned by the recent earthquake off Japan did most of the damage we know about so far. The U.S. National Oceanic and Atmospheric Administration’s Center for Tsunami Research uses computer models to forecast, and provide warnings about, incoming tsunami waves. They have an amazing simulation showing the propagation of the recent tsunami across the Pacific Ocean (the YouTube version is here).

Images captured from the NOAA simulation. The full resolution, 47Mb video can be found here, on NOAA's site.

They’ve also posted an amazing graphic showing the wave heights in the Pacific Ocean.

Tsunami wave heights modeled by NOAA. Note the colors only go up to 2 meters. The maximum wave heights (shown in black in this image), near the earthquake epicenter, were over 6 meters.

Of course, these are the results of computer simulations. As scientists, the people at NOAA who put together these plots are always trying to improve. Science involves a continuous series of refinements to better understand the world we live in, so the NOAA scientists compare their models to what really happen so they can learn something and do better in the future. Perhaps the best way to do this for the tsunami is by comparing the predictions of their models to the actual water height measured by tidal gages:

The red line is the tsunami's water height predicted by the NOAA computer models for Honolulu, Hawaii, while the black line is the actual water height, measured at a tidal gauge. Other comparisons can be found here.

You’ll notice that NOAA did not do a perfect job. They did get the amplitude (height) of the waves mostly right, but their timing was a little off. Since it’s about 6000 km from the earthquake epicenter to Honolulu, being off by a few minutes is no mean feat. Yet I’ll bet they’re still working on making it better, particularly since some of the other comparisons were not quite as good.

Finally, if you were wondering, attempting to surf a tsunami is not a good idea. For one thing, there is no nice face to surf on:

… a tsunami wave approaching land is more like a wall of whitewater. …. Since the wave is 100 miles long and the tail end of the wave is still traveling at 500 mph, the shore end of the wave becomes extremely thick, and is forced to run far inland, over streets and trees and houses. …. And remember, the water isn’t clean, but filled with everything dredged up from the sea floor and the land the wave runs over–garbage, parking meters, pieces of buildings, dead animals.

— Natural Hazards Hawaii, University of Hawaii at Hilo: Why you can’t surf a tsunami

UPDATE: Terrifying video of the tsunami:

Erosion in action

With a little help to get started, the water erodes a channel, transporting sediment to the ocean.

For what it’s worth (and it seems a reasonable explanation to me):

The beach sits at the base of a valley which has a small stream running through it. Due to wave action, sand gets pushed up into a large hill in front of the stream each winter. This creates a natural dam that the stream water collects behind for months which is about 20 feet above the level of the ocean on the other side of the sand berm. Every year some one digs a trench through the sand releasing millions of gallons of fresh water into the ocean.
– YouTube User:Hackfleischhasser comments on the video Waimea River

Keynes and Hayek

I used my notes and the Keynes versus Hayek music video as part of our reading this week. As usual, half the class tried skipping directly to the video, but it became pretty clear, as I suspected it would, that they didn’t understand what was going on if they had not read the notes.

We’ll be discussing the video tomorrow when we try to wrap up the week’s work, but, as one student mentioned, it can be a little hard to figure out the words in the rap. Fortunately, the Econ Stories website has been updated to include the lyrics.

Even without the lyrics, however, I really like that you can get a good idea about the competing economic theories solely from the video itself, since it’s just a very detailed extended metaphor. It’s so chock full of symbols that it could probably be used to supplement the Calvin and Hobbes comic strip in our language lessons on finding symbols in texts.

How protests lead to revolution

The events that spark revolutions can come as a surprise. While everyone at home might want to overthrow the dictator, they don’t know if everyone else wants to do so too, so they are reluctant to go against the government. This is why protests are so important (as well as news coverage of the protests), because then the people offended by the government can see that there are a lot of other people like them.

Dictators, like Mubarak, do a lot to prevent protests: their secret police will arrest and “disappear” opposition leaders; riot police will be out in force to suppress protests if people start to gather.

The Egyptian protesters faced this very problem. So they organized over the internet, as anonymously as possible, and, for the January 25th protests, they arranged several meeting places for protesters so the riot police were too spread out to suppress everyone.

Stephen Pinker talks about this in terms of Individual Knowledge and Mutual Knowledge. Individually everyone knows the dictator is bad, but with the protests, they all realize, mutually, that everyone else also thinks the dictator is bad. Which is really bad for the dictator.

What Victory Looks Like!

The resignation of Hosni Mubarak and the deafening sound of celebration in Egypt (via the Guardian).

Egypt. A victory for peaceful protest (even though they had to fight off attacks).

Going forward, things will not be easy, but for today, euphoria. Will Wilkinson has an excellent essay, in which he puts aside his natural skepticism for a little while:

It is impossible, for me at least, to watch the crowds in Egypt, overjoyed at Hosni Mubarak’s hotly-desired resignation, with dry eyes and an unclenched throat. … Whatever the future holds, there will be disappointment, at best. But there is always disappointment. Today, there is joy.
–Will Wilkinson (2011) Egypt’s Euphoria

Fireworks are necessary:

The singing (via NY Times) before Mubarak’s resignation:

And after:

To be liberated is one thing, but to earn your freedom is fundamentally at another order of magnitude.

Uprising in Egypt

(via The Daily Dish)

What protests look like:

See also:

  • Summary of the last two days’ protests.
  • The United States’ support for Egypt.
  • What happens when you’re arrested by the state security service. (warning: contains one quote with vulgar language)

UPDATE: We just watched the video over lunch, and it actually resulted in a very good discussion. Our morning novel discussions have been useful here, in helping us see the multiple perspectives of the actors in the street protests: the protesters and the police. After all, the police have families too.

I gave a little spiel at the beginning, to set the stage and to point out the potentially historical nature of these protests. Democracy spreading through the middle east has huge implications for a country fighting two wars in the region; not to mention the blowback from these conflicts.

The truth of the anger of the protesters in the video seemed to resonate, making poignant what could have appeared farcical. The music and the Kennedy quote also helped my students identify with these events in such a far off place.

We also touched on the role of the U.S. in supporting the Mubarak government, and the potential of the uprising to lead to an anti-US, muslim fundamentalist government (via the Muslim Brotherhood). We still need to talk about what the US should and can do to support democracy in this situation, which is so full of conflicting imperatives.