Monday, April 6, 2009

What Happened?

Last night, I skimmed over the news about the quake in Italy... one headline described it as a "disasterously powerful 6.7." Now 6.7 is not trivial, but neither, in most cases, is it going to be "disasterous." So I didn't read in detail, nor have I yet... I'm just startled that it's as big a mess as it is.
Photo reduced from Speigel; see the full gallery here.

My assumptions, as I skipped the details, were these: Italy is a relatively modernized country, with (I presumed) fairly decent and enforced building codes. I assumed that Italy has a long history of earthquakes, which on one hand gives experience in building resistant structures, and on the other, over time weeds out less resistant structures. Finally I assumed that culturally, the Italians were probably better prepared to cope, due to their experience with the shaking earth over the last two or three millenia.

As I'm trying to make clear, I really haven't read much in the way of details yet; I'm just reacting to the shock I'm feeling for so misunderestimating the situation as I tried to get my butt out of here last night. My reassment of my assumptions is more or less this: most of the collapsed buildings look to be masonary, with little reinforcement (I'm not seeing a lot twisted rebar sticking out of the rubble). They look to be older buildings, not modern. So building standards are clearly not what I was guessing. Perhaps there are fewer and less frequent earthquakes than I had assumed, at least in this region of the country.

I guess the point is, even a moderate earthquake can cause devastating results if a region isn't prepared. It's a good lesson for those of us in the Pacific Northwest, and one we should take to heart.

Followup, 5:50 PM: USGS is saying this was actually a 6.3; the Italian geological service is saying 5.8. Either way, it was less powerful than I first heard. Apparently, suspicions are that corruption, looking the other way for a bribe, played a role. And while it was less powerful than I first read, it was still more powerful than most earthquakes in the region. The most devastated areas were those with older (centuries older), unretrofitted buildings. I'm still a little stunned by the destruction from what to my mind is a fairly moderate event.

2 comments:

Dean Wormer said...

You're the geologist but couldn't duration of also had some affect on the damage done? Or is that figured into the richter rating?

The Young Swell said...

Your surprise at the amount of destruction seems well-placed:

Franco Barberi, who leads a commission on assessing risks for Italy’s Civil Protection agency has said, “In California, an earthquake like this one would not have killed a single person.” adding, “Once again we are faced with the lack of control on the quality of construction.”

Italian Prime Minister Silvio Berlusconi said “this is not the time to raise questions about the past; we must concentrate on relief efforts.”

True, but why does that comment sound so familiar?

http://tinyurl.com/c7wajp