This morning, many Americas awoke to the tragic news that an magnitude 6.9 (or 7.1, according state-run China Earthquake Networks Administration) earthquake had struck the western Chinese province of Qinghai. The initial reported death toll made it seem as though the population had perhaps dodged a bullet, but there have now been close to 500 casualties identified, with another 10,000 injured. And if we use history as a guide, these numbers may very well increase as well. Heart-breaking.
Still, when you consider that the 2008 Sichaun quake struck along the same Longmenshan fault system in a more populous region and killed some 90,000 people, things could have been worse. And in a year where another powerful, seismic event shakes the globe seemingly every week, that is at least one thing to be thankful for as the region tries to launch successful rescue and recovery efforts.
But has the earth really been producing more major quakes? It sure seems like it, and Newsweek gives a rundown of the recent evidence:
Yesterday, a 6.9-magnitude quake struck Qinghai, China, resulting in an estimated 400 dead and 10,000 injured. One week before that, a 7.7 tremor hit Northern Sumatra, Indonesia. Two days before that, a 7.2 shook Baja, Mexico. At the end of February, Chile shuddered under an 8.8 earthquake, little over a month after a 7.0 crumbled Haiti and killed nearly 230,000. With such a list, 2010 appears to be the year of the apocalypse or, at the very least, unnaturally active for these natural disasters.
But it is not.
According to the United States Geological Survey, seismic activity in 2010 has been well “within the normal range.”
Scientists say 2010 is not showing signs of unusually high earthquake activity. Since 1900, an average of 16 magnitude 7 or greater earthquakes — the size that seismologists define as major — have occurred worldwide each year. Some years have had as few as 6, as in 1986 and 1989, while 1943 had 32, with considerable variability from year to year.
With six major earthquakes striking in the first four months of this year, 2010 is well within the normal range. Furthermore, from April 15, 2009, to April 14, 2010, there have been 18 major earthquakes, a number also well within the expected variation.
“While the number of earthquakes is within the normal range, this does not diminish the fact that there has been extreme devastation and loss of life in heavily populated areas,” said USGS Associate Coordinator for Earthquake Hazards Dr. Michael Blanpied.
The last line is the key.
There aren’t more earthquakes. There are more people.
And that is why the need for better preparedness, building codes and emergency response is greater than ever. The worst-case events of the recent past may not actually be worse than the true true worst-case disasters we will see in the future. (For reference, here are the 11 deadliest earthquakes in history.) With the global population projected to reach nine billion by mid-century, there will be way more people who are — quite literally — atop shaky ground.
We have seen a similar phenomenon both in the United States and globally in terms of hurricane/windstorm risk. Whether or not hurricanes are actually increasing is debatable (and not something I want to get into here), but what is undisputed is that more people today live near the coast than ever before. Internal migrations and population booms in recent decades have left more people directly in the path of the storm.
And now, we are seeing how the same thing can — and will continue to — tragically play out near fault lines.
UPDATE: Here’s a feature we ran way back in 2005 (pre-Katrina even) detailing the increasing danger disasters pose to coastal communities. Obviously, the stats are a little dated, but the general trend has not changed.
[All this recent storm] activity underscores just how precarious it is to live and work on the world’s coasts. Despite this, the United Nations has estimated that 37% of the world’s population lives within 100 kilometers (about 62 miles) of the coast. In theUnited States, coastal areas make up one-fifth of the landmass but are home to more than half of the population. And according to a paper by Charles Colgan, chief economist of the National Ocean Economics Project and professor of public policy and management at the University of Southern Maine, 75% of the U.S. domestic economy came from coastal areas in 2000. With these numbers steadily increasing, it is vitally important to understand the natural catastrophe risks related to coastal development, especially in light of what was a particularly active year for such events.
Our other editor Morgan O’Rourke wrote the piece and breaks down both tsunami risk and the memorable 2004 hurricane season if you want to read more on the topic.
UPDATE II: EQECAT, a leading catastrophe risk modeling company, released an update on the Qinghai quake, announcing that — as expected — the insured losses will be “minimal.”
Approximately 16,000 people were exposed to strong ground shaking, and hundreds of deaths have been reported, primarily due to the particular earthquake-vulnerability of the of the conventional mud-brick construction. Though this earthquake has caused immense consequences to the people affected, its significance among the insurance community will be minimal. The Yushu prefecture in which the earthquake was centered contributes a fraction of a percent to China’s GDP, with primary industries of herding and farming, as well as limited tourism related to Buddhist monasteries throughout the region.
Seismic activity in the Tibetan plateau is related to extrusion within the Eurasian plate resulting from convergence of the Indian plate along the Himalayan front. Extrusion-related earthquakes with moderate to large magnitudes, of which the magnitude 7.9 2008 Wenchuan earthquake was one example, are known to occur throughout central China from the Himalaya northward.
