Fleas

Westerners shouldn’t be too sure they’re safe from tsunami-type catastrophes

© Bryan Zepp Jamieson

12/27/04

http://www.zeppscommentaries.com/S&E/fleas.htm

I was looking at a heart-rending picture from Sri Lanka of a mother crying over the bodies of four of her children, and a passer-by, glancing at the picture, said, "Aren’t you glad we live in the mountains?"

Well, it’s true that being 3,600 feet up and 100 miles inland means that tsunamis are not our number one concern. Any tsunami big enough to hit us means an end of the world event just occurred, such as an asteroid the size of Manhattan landing in the Pacific. Sloppy phrasing; scientists prefer "extinction level event" instead of "end of the world event," since the planet would still be around. Extinction level events are comparatively common, and there have been several dozen that we know about, starting with the impact that created the moon.

An extinction level event is something that can wipe out at least half the life on earth, including all or nearly all carnivores. As noted, these things happen from time to time. The last one, an asteroid strike in what’s now the Gulf of Mexico, took out the dinosaurs some 69 million years ago.

Asteroid slaps are fairly rare (although we witnessed a cometary collision a few years ago on Jupiter that caused explosions roughly the size of planet earth, and less than a hundred years ago, a comet struck Siberia, flattening the forests for a hundred miles around, a reminder that these little celestial spams aren’t all THAT rare).

There are lesser events that cause radical change around the world, through sudden and dramatic shifts in climate. Those could be called "civilization-ending events," and we’ve had one of those. In 535, a massive volcanic eruption in Indonesia (probably Krakatoa) split a large island into what’s now Java and Sumatra, and dumped enough ash and particulate matter into the upper atmosphere to bring on about three years of nuclear winter. Every advanced (for that time) civilization collapsed, since civilizations, then as now, aren’t prepared for a 90% decrease in the food supply. Indeed, scientists estimate that in the wake of this hyperplinean (the word derives from the fact that Pliny the Elder witnessed – and wrote about – a much smaller eruption by Vesuvius in 79 AD) eruption, it took at least 20 years for the climate to reach a new equilibrium. It took several hundred years for humanity to gain back the ground lost – a period known in Europe as "The Dark Ages."

Incidently, if you’re wondering if this week’s earthquake might have had something to do with Krakatoa, the answer is a firm "maybe." Anak Krakatoa (the present cone at Krakatoa, literally "Child of Krakatoa") isn’t unusually restive right now, but it’s part of the same tectonic edge as where the earthquake occurred, some 500 miles away.

Incidently, plate ruptures are rare, but can be extinction level events, since they can trigger massive volcanic eruptions to occur simultaneously along the border of two plates for up to a thousand miles. That could poison the entire atmosphere and make the entire surface of the planet pitch black for decades. Only deep sea life and microscopic life near the surface would survive. Just a little something to think about while you’re trying to go to sleep tonight.

But we’re almost certain that’s not what’s happening here. Nothing to see here, citizen; just move along.

I wonder if the guy who was so smug about our locale (on the flanks of a large and eventually deadly volcano, yes) knew that a town only one hundred miles away got hammered by a tsunami just a little over 40 years ago. Crescent City, a small California town near the Oregon border, was hit by a tsunami in the wake of Alaska’s Good Friday quake (9.5 magnitude) in Prince William Sound in 1964. Eleven people were killed, and about a quarter of the town destroyed.

It’s not entirely certain that the elaborate tsunami warning systems that North America and Japan have would really save that many lives. There was a major earthquake at one point in the 60s, and the Harbormaster in Santa Barbara issued a tsunami alert. Thousands of people flocked to the beach to "watch the big wave come in." Fortunately for Santa Barbara land values, no such wave appeared.

The west coast not only can be affected by tsunamis, but it can generate them. Back on January 26, 1700, around 9pm, a 9.5 earthquake struck Oregon. We know the time so well, not because the local tribes had good calendars, but because the Japanese did, and were meticulous record keepers. They duly noted the tsunamis that struck up and down their entire east coasts. Historians noted the records, and backtracked, since the Japanese recorded the direction the waves came from, and gave good accounts of the time and even speed estimates. The waves all pointed back to the Cascadia subduction zone, and they looked over the paleobotanical record in the area, and discovered the forests had a massive quake about 1700.

We can tell when earthquakes occurred, but we still can’t predict earthquakes with any reliability. There is no warning system for a 9.5, which could send ground waves 25 feet high moving across the local landscape at 200 miles per hour. This would be very bad for property values, which is why it’s so puzzling that we haven’t come up with something yet.

The east coast may be susceptible to a "super tsunami." One of the Canary islands consists of two huge slabs of rock leaning against one another, and should the one facing out to the ocean happen to collapse (and it’s believed that it will someday) then it could generate waves up to two miles high that would smash the entire eastern seaboard. Such waves could possibly sweep across the entire state of Florida. Even with 18 hours warning, they couldn’t evacuate the tens of millions of people who would be in harm’s way.

Mind you, these aren’t extinction level events, or even civilization ending events. Those are still fairly rare. These are comparatively minor events, just like yesterday’s earthquake in Sumatra was, and are common as fleas in a dog pound.

And of course, you still have your every day catastrophes, such as the 7.0 earthquakes or the magnitude four hurricanes, or tornados, blizzards, fires, floods and droughts.

So when I talk about the possibility of extinction level events, I’m not trying to denigrate what happened to Southeast Asia yesterday, or scare the piss out of everyone. Mostly I’m not even really telling you much of anything you don’t already know, at least in a general sense.

Bad things happen. Sometimes BIG bad things happen. They can happen anywhere, at any time. That’s why insurance companies are so rich and powerful.

Just because you might be inland, or not in the path of a big earthquake, or near any volcanoes or whatever, doesn’t mean you’re invulnerable.

So don’t be smug.