As we approach the first anniversary of the March 11, 2011 Great Tohoku earthquake and the associated tsunami, the people of Japan are not feeling particularly earthquake-ready, as discussed in this morning’s print edition of the Washington Post.
Hard to blame them.
Let’s review the numbers for last year’s event. A quake of magnitude 9.0. Tsunami waves reaching heights as great as 130 feet. The earthquake moved Honshu, Japan’s main island, eight feet east and shifted the entire Earth on its axis by maybe half a foot. The energy release, could it have been harnessed, would have met all of our energy needs, worldwide, until the year 2100 – a full century.
Some 15,000-20,000 people died. Another 300,000 were displaced from their homes. Damage and economic disruption totaled a quarter of a trillion dollars. Three of the nuclear reactors at Fukushima melted down, triggering an additional massive evacuation. In the aftermath, most of Japan’s nuclear reactors (which produced about one-third of the country’s electrical energy) were shut down. A month ago, 49 out of 54 Japanese reactors were still off-line.
Which brings us back to this morning’s newspaper article. Turns out about a month ago two seismologists at the University of Tokyo “forecast” that a major earthquake would hit the city within the next four years. Recall that the Great Kanto earthquake of 1923, though only a magnitude 7.9, killed over 100,000. Most (including 38,000 people packed into Rikugun Honjo Hifukusho who were incinerated by a firestorm-induced fire whirl) died from fires. High winds from a nearby typhoon contributed to deaths from this secondary cause. Were such an earthquake to occur again today, estimates are that the economic cost might reach one trillion dollars. And the loss of life might again depend upon the prevailing weather at the time.
Speaking of weather…most of us are familiar with weather forecasts. We know they’re the product of massive assimilation of data on weather conditions around the entire world into computerized numerical models. We get to see the results on a daily, even hourly basis, so that each year, each of us has hundreds of experiences with weather forecasts. Over time, we develop a feeling for how well they prove true. There’s quite a dialog among scientists and the public about uncertainty; how it should be characterized and used.
What’s the story with earthquake prediction? Here there’s much more mystery. Like meteorologists, seismologists start with persistence. They look at historical data for earthquakes in a different location, and figure that those past statistics will pretty much continue into the future. They try to improve upon this picture by searching for precursors…changes in water table, in “swarms” of microseismic activity, pre-slip deformations of rock deep beneath the surface. They look for exhalations of radon gas. They measure electrical conductivity of the ground. They monitor animal behavior. You name it…they’re measuring it…hoping to get lucky, hoping to stumble across some silver bullet.
Did you see anything in that paragraph about collecting massive amounts of data throughout the breadth and depth of the Earth’s crust? Of initializing huge computer models to measure shifts and movements, and to monitor the build up of accumulated strain? We try to do those things, but the state of forecasting is much more analogous to the weather forecasting folklore discussed here on February 15.
The Washington Post article states that the Japanese are spending “$100B” annually on earthquake prediction. [sic; that’s 2% of Japanese GDP; I’m wondering if the correct figure isn’t ¥100B; roughly one percent of that amount.]
$1B/year wouldn’t be at all out of line considering Japan’s exposure to this threat. The western coast of the U.S. is part of the so-called Pacific “rim of fire,” seismologically and volcanically active. The entire nation of Japan (with a land area about the same as California) sits atop that same rim of fire. The United States and Japan each host perhaps two dozen active volcanoes. For the most part, the U.S. volcanoes are remote…in the Aleutians. The active Japanese volcanoes dot their entire landscape. In some Japanese towns, parents send their kids to school every morning wearing tiny kid-sized hard hats…in case the local volcano starts spitting some ash/projectiles during the day. [How would U.S. “helicopter parents” cope with that?]
So in Japan, seismic and other geological threats are very much on everyone’s mind. And that was before last year. The preoccupation is greater today. Now those two Japanese researchers have noticed that since that March event, microseismic activity centered around Tokyo has picked up. Using the Gutenberg-Richter law, they forecast a major Tokyo earthquake sometime in the next four years.
The question is…what constitutes being “earthquake-ready” in the face of such a forecast? In many respects, the situation most Japanese face looks similar to a U.S. family that receives a tornado warning, but has neither a tornado shelter nor a safe room in their home. What options are available to our Japanese family? Perhaps their residence is seismically engineered…but to withstand an earthquake of such great magnitude? As recently as the 1995 Kobe earthquake, the majority of deaths were still caused by fire. Moreover, in Kobe the elderly were hardest hit. Japanese tradition has families living in two-story homes, with the elderly on the ground floor so that they don’t have to navigate the stairs. Many of these homes collapsed, pancaking, and killing the ground-floor occupants. If this outlook were to be followed some day by a warning such as “Tokyo will be hit by a magnitude 7.0 earthquake tomorrow,” then perhaps an evacuation at that time might be an option. But no such pinpoint warning is in prospect. And furthermore, coastal residents get to practice hurricane evacuations every few years. People have some sense of what to do. But that first earthquake evacuation? Based on a prediction? How should that first set of warning messages be framed? Who expects any such evacuation to go well?
So…should Tokyo’s citizens emigrate? Pick up and leave Japan for safer shores? If they stay in place and simply worry or hide a private sadness for four years (or forty), is that being earthquake-ready?
And if you live in the United States, no reason to feel smug. The U. S. Geological Survey tells us there’s a 37% chance that the Cascadia Subduction zone will rupture (magnitude 8.0) just off the Pacific Northwest within the next 50 years, producing a 100-foot tsunami. That New Madrid fault in the central United States that produced the largest (three) earthquakes in U.S. history, 200 years ago? A 7% chance it’ll do the same sometime in the next 50 years.
So…the infrequency of the earthquake threat; the immense physical forces involved, the high cost of building resilience to these forces, either with regard to housing or critical infrastructure; our attachment to place; and the rudimentary state of geological monitoring and predictive capability all combine to make “earthquake-ready” an elusive will-o-the-wisp, if not an oxymoron. Political leaders and the public throw up their hands. We content ourselves with half-measures (or less).
That is regrettable. The earthquake threat is nearly universal worldwide. The Middle East – that global powder keg? Fault lines criss-cross it. In addition, recent years have seen major quakes and/or tsunamis in Latin America, the Caribbean, China, India, Indonesia, New Zealand…
These recent events have been severe, but by no means worst-case scenarios. Events with the ability to change the course of history lie ahead. Currently, countries of the world are playing Russian roulette with this threat. Each nation engaged in the market competition and more importantly, the competition for ideas, is hoping that tragedy strikes others before it strikes at home.
The stakes are too high to rely on chance. Countries wishing to preserve their values and ideals (e.g., democracy, liberty, freedom of worship, equality of opportunity), serious about their culture and sustaining their contributions and influence over time ought to take more seriously the earthquake threat (and the threat of other hazards for that matter). They ought to be gradually replacing their existing housing stock and infrastructure with structures and communities that are located out of harm’s way and built with an extra margin of resilience. They ought to be accelerating investment in Earth observations, science, and services, with an eye to seeing threats early rather than after the fact. They ought to be building social and natural capital…not just domestically but internationally.
In fact, extending a helping hand internationally, building relationships and collaborations across borders in anticipation of such future threats is arguably the cheapest, most cost-effective single action we can be taking now to make a better, more peaceable future world.
