What About the Earthquake in Japan?

Hello,

I have a question for the omniscient Madame L (finally!). Is it true that the Japan earthquake from this week moved the earth's axis 10.0 cm, moved Japan 8 feet and sped up the rotation of the earth?

Dear Reader,

Thanks for your confidence in Madame L, who only wishes she could characterize herself as omniscient.

Madame L is fortunate to have a friend who is a geoscientist, to whom she relayed your question.

Here is his response:

Your questioner is both well informed and astute. Northern Japan DID shift roughly westward nearly 3 meters, and the Earth's axis DID shift 10 centimeters. To put things in perspective, the Earth's axis is slowly shifting all the time, but not by this much, nor this fast.

To add another element to your questioner's perspective, a magnitude 9 earthquake event means that the crust east of Sendai Japan ripped at least 1000 kilometers laterally, and probably at least another 40+ kilometers down-dip in the direction of the thrust fault.

While geologists have found bisected mountain ranges crossing the San Andreas Fault that have been shifted ~120 kilometers between what once were contiguous points, that sort of movement doesn't happen overnight --- or the Coast WOULD be Toast.

The San Francisco earthquake of 1906 had a right-lateral tear nearly 6 meters (18 feet) in one place - but not over such a large distance.

Perhaps more astounding to your geoscience advisor is the fact that there have now been over 150 aftershocks (and a few close-in foreshocks) with magnitudes from 5 to 8 associated with the Great Sendai Earthquake.

Keep in mind that a magnitude 7 earthquake releases about 10 times more energy than a magnitude 6 event - the magnitude scale is logarithmic. Nevertheless, there was still a HUGE amount of energy released AFTER this event, now called the greatest crisis in Japan's history since WWII.

If all those aftershocks had dumped their energy at the same time, I hesitate to think of how much worse it could have been. This event was also pretty shallow - aftershocks continuing this morning (I'm looking at an earthquake app on my Droid keyed to the USGS database) range from 5 km to 40 miles deep. The shallower the event, the less crustal dampening occurs.

The only event I can think of that is comparable in magnitude is the 1960 Chile earthquake... which destroyed downtown Hilo, Hawaii (I've seen tsunami run-up markers 40 feet above sea-level in what is now a city park; a geologist friend calls it "unplanned urban renewal").

Some people have been questioning why the nuclear reactors failed. Any engineer tries to design their creation to survive a certain level of event, but you could never plan for everything (like 767 aircraft flying into your building) or you could never afford to build ANYTHING.

At this time, whole towns in NE Japan are unaccounted for, and the death toll may run into the multiple thousands.

What worries THIS geoscience advisor more, however, is the fact that the Fukushima Daiichi reactor and perhaps at least one other may have been so fatally damaged that, even with all the fail-safes built into these things, their cores could go supercritical.

Remember Chernobyl? The heat and pressure of this fatally-compromised old-style reactor blew out *upwards* and dusted most of Europe with enough radioactive iodine to contribute perhaps ~7,000 additional thyroid cancer deaths than would have been normal at this time.

There is a (currently failing) protective concrete structure above (and at enormous risk and expense also below) the Chernobyl reactor.

A core meltdown at Fukushima, however, is something else: it could melt its way down to the water table and even gain access to the sea, which would lead to an enormous steam explosion. In volcanology, we call water-touching magma events phreatic explosions - they blast huge tonnages of rock and ash to great altitudes and (under prevailing winds) lateral distances. Of all the dangerous radionuclides in a reactor core, however, plutonium is the most toxic - microgram for microgram, it is more toxic than botulin.

Imagine large quantities of plutonium getting into the coastal waters off NE Japan, a seafood-consuming nation.

It's too late to ask the engineers and planners "What were you thinking?" --- to build a nuclear reactor so close to a major subduction fault, but Japan didn't have all that much land to build one on in the first place - nor had the Japanese ever experienced an earthquake of this magnitude in all its recorded history.

The general rule of thumb for volcanologists is that history is the key to the future: map the deposits and calculate the explosive force of previous eruptions, and you'll have a good idea of what to plan for in the future.

Doesn't work always, of course. It sure didn't work for Japan.

Nor are other energy solutions free of "sin" - antagonists to coal, tidal energy, solar energy, and especially windmills are legion. I once saw a bumper sticker in Tucson, around the time that a mining company wanted to develop a property, and a lot of environmentalists (for some, that's an alternative religion) fiercely objected. The bumper sticker said in large block letters "BAN MINING," and in smaller letters below that, "...Let the Bastards Freeze in the Dark."

There are people who object to clear-cutting old-growth forest. I suspect that they live in wooden houses, and would be willing to bet that they don't bike everywhere they have to go.

I suppose I'm saying that we have to balance all things, and a *measured* dialog between interested parties will always work out some sort of optimum solution.  Note I didn't say *perfect* solution.

The coast from Vancouver Island to California has its own mirror image of the Sendai subduction Fault. Cores of bouma (laminated mud) sequences off the Oregon and Washington coast tell us that huge M ~ 8 subduction events (that is, earthquakes caused by continental crust riding up and over a down-going slab of denser oceanic crust) have occurred at least 7 times in the past 3,500 years.

The last one happened in 1700 AD, and sank whole forests near Seattle below sea level in Puget Sound. That event caused something called the Orphan Tsunami that came out of a clear blue sky sans earthquake (ergo, the name - the Japanese already knew to run to high ground if the earth shook) and obliterated a number of villages on this same Japanese coastline.

Scientist know that earthquakes on major faults do NOT follow a clock-like regularity, so we could say that we are "due" a big event in the Pacific Northwest sometime.

We still bought our house on a hill (for the view). We could spend our lives living in fear and trying to find some safe place to build our homes in this country... and there just ain't a place safe from all natural disasters. There are other ways to prepare, however, and we do these.

So I will continue to savor my view each evening before I go to bed.

I will also be contributing money to help my brothers and sisters in Japan, something that I expect they may very well do for me or my children in the future.

We all live on the same planet. We're all part of the same family.