Shaken, Not Stirred

I have a lot of things to write about my week in Italy, but I think I’ll start with the earthquakes.

Earthquake Activity This Week
October 2016 earthquakes in Italy
October 2016 earthquakes
Click image to enlarge

I arrived Monday afternoon and went to Urbisaglia where I stayed in a small, older hotel in the village center until Friday morning. It’s located about where the blue circle is on the map of the quakes that’s on the right of this page.

Wednesday evening about 7:10 pm I was in my room and it shook a little bit. Just a couple of seconds but very noticeable. This one was magnitude 5.5. I figured it was an aftershock to the August 24 quake — rather than being a before-shock for those to come.

About two hours later I was at dinner about 3 miles away, on the bottom floor of a newer (1960s? ’70s?) building and the shaking started again. Everyone bolted for the door, including me, of course. Outside, people were visibly shaken. Some were crying.

The shaking lasted longer this time and was stronger, measuring 6.1. (That difference from 5.5 doesn’t seem that great, but the scale is logarithmic, so this one was roughly 10 times as strong as the first one.)

When I returned to the hotel, the owner came to my room. He reassured me that the hotel was in a building that had been restored to meet earthquake standards.

There were some smaller shocks during the night.

On Friday, I went to the larger town of Macerata. Located where the red circle is, it’s the provincial capital and about 40,000 people, compared to about 3,000 in and around Urbisaglia. Lots of older buildings.

Saturday evening there was a small quake. You could see and hear the television rattle on the table. Magnitude 4.5.

October 2016 earthquakes in Italy
Earthquakes
Click image to enlarge

Now the big one. Sunday morning I was just getting up, about 7:40. The room started to shake like crazy. I’m trying to figure out where to go. I’m not dressed, on the fourth floor, with no obvious place to go where the structure might be strongest. I’d say this was 10 seconds of serious fright. Once the shaking stopped, I got dressed, grabbed my stuff, and got to the ground floor and outside. This was a 6.6 quake, so about 30 times stronger than the first one on Wednesday.

Now I had just one problem. The car was in a garage a couple of blocks away and I needed to go back inside to get the keys to get the car.

I didn’t see any visible damage to the buildings nearby, but I wasn’t going to explore. I got the car and drove toward the coast. I wanted out of the hill towns. (My original plan was to go to a sagra delle castagne — a chestnut festival — in a small town in the mountains. It was almost certainly cancelled, but I wasn’t going there to find out.)

On the way to my next hotel near the coast and the airport, I decided to stop at IKEA just to what they had that we might use in the house. To my surprise, it was closed, at least for a couple of hours, I assume to check the building.

Some Perspective

While this week and year have been very active seismically, history shows this level and severity is very unusual. I found a list of quakes in Italy. In Marche, there have been 9 over 5.0 Here’s the list, with dates, in order of severity.

Month/YearMagnitude
Oct 20166.6
Aug 20166.2
Oct 20166.1
Sep 19976.1
Oct 19305.9
Oct 20165.5
Oct 19435.5
Oct 19365.5
May 19875.1

So the top 3 and number 6 have been this year.

I’m hoping that the pressure on the faults has already released and we may be in for another quiet period. And our house is being built to standards to survive, at least long enough to escape, in an 8.5 or so, and there’s never been a quake nearly that big in Italy.

So the risk we do face is when we are in a village somewhere and there is a 6.0 or over.

An Update

I’m now back from my trip and a 4.9 aftershock was recorded today in the same area. Also, scientists are using satellite imagery to assess the quake and the likelihood of future events. Here’s a quote from a BBC story:

The colored bands represent motion toward or away from the satellite
Earth movement: The colored bands represent motion toward or away from the satellite.
Click image to enlarge

There remains the potential for future quakes in Italy’s Apennines region, say scientists who have reviewed the latest satellite maps of the region.

The new radar imagery suggests Sunday’s big tremor ruptured a segment of a fault in between sections broken by two other quakes in recent weeks.

But the Magnitude 6.6 event has still left the deeper parts of the fault system locked in place. And this unrelieved stress now represents a risk down the line.

The researchers are keen to emphasize, however, that predicting precisely when and where a future quake might strike is not possible.”

Map sources
USGS, NERC

Leave a Reply

Your email address will not be published.