As many of us watched the coverage of the Sendai earthquake and tsunami in Japan on Friday, we were staggered and horrified by the images of death and destruction. The magnitude 8.9 quake is the largest to hit Japan in more than 150 years and the seventh largest in recorded history. The tsunami produced even greater damage and loss of life. The final figures won't be known for many days, yet it seems clear that hundreds and possibly thousands of people are dead, injured or missing, and the economic toll will be in the millions. The quake will have a severe effect on the Japanese economy, the third largest in the world, and it is already having a global effect.
Despite the catastrophic effects that the quake has on Japan, it could have been far worse. Japan is one of the most earthquake-prone countries in the world, and it has better building codes and better civic preparedness than just about any other nation. The Japanese take their earthquakes very seriously and do far more drills and inspections than Californians. Yet even some of their earthquake-resistant structures could not survive the shaking of a quake this big, just as their buildings and overpasses failed catastrophically during the 1995 earthquake in Kobe. From all accounts, there were adequate tsunami warnings in most regions, but those people closest to the offshore earthquake had almost no time to react or flee, and there was nothing they could do when the huge waves swept inland carrying big fishing boats and tons of debris.
The Sendai quake is a warning and a reminder that we Angelenos live in earthquake country too. Anyone who has lived in this area for more than a few years has experienced at least a few small quakes, and those of us who are long-term residents remember the 1971 Sylmar quake, the 1987 Whittier quake, the 1994 Northridge quake and others. The scientific community has studied the major faults in our region for years. Scientists have been digging trenches in ancient lakebeds near fault lines to find evidence of how often earthquakes occur on each major fault. They have detailed computer models of how the next big quake will affect us and which areas are most vulnerable. Their conclusions have been stated time and time again: Several of the faults in our region are overdue for major quakes. The latest forecasts say there's a 99.7% chance of a magnitude 6.7 earthquake in Southern California in the next 30 years, and a 46% likelihood of a much more powerful magnitude 7.5 quake (still hundreds of times smaller than the Sendai quake) in the next 30 years. The San Andreas fault is capable of an even larger one.
It's not a question of whether we're due for a catastrophic quake, but when. Although California building codes are among the most stringent in the United States (thanks to what the 1933 Long Beach quake, which destroyed nearly all of our unreinforced masonry buildings), they don't begin to match the standards demanded in Japan. Just consider the high overpasses where the 5 and 14 Freeways meet — which fell in the 1971 Sylmar quake; their replacements fell in the 1994 Northridge quake — and you begin to realize just how vulnerable our infrastructure is. And those quakes were only 6.6 and 6.7 in magnitude — thousands of times weaker than the Sendai quake.
Thus, the news from Japan is not only a sobering reminder that we are also in the cross hairs; it is a warning that we must take the threat seriously. Seismic engineers have been advocating clear-cut standards for construction, some of which are followed but much of which are ignored. Most engineering experts tell us that we have neglected the infrastructure and earthquake safety issues for too long. We continue to put it off because of budgetary issues and the current bad economy. But when the next Southern California quake happens as predicted, we will all be looking back and pointing fingers of blame at "penny wise and pound foolish" people who did not spend the money that would have saved even far more money — and many lives.
On a more personal level, each one of us needs to take these warnings seriously and pull our heads out of the sand. Does your house have an earthquake kit for the long days without water, power, food and easily obtainable cash? Has your house been made as safe against earthquakes as possible? Those who ignore these warnings now will regret it later when the next Big One hits.
Donald R. Prothero is a professor of geology at Occidental College in Los Angeles and a lecturer in geobiology at Caltech. His latest book is "Catastrophes! Earthquakes, Tsunamis, Tornadoes, and other Earth-Shattering Disasters."