Engineers sound earthquake alert for urban rebuilds

With a “seismic crisis” registering hundreds of low density quakes throughout Portuguese territory this week, the head of the country’s Order of Engineers has gone on record to say the government must revise the law on seismic security “as fast as possible”. Carlos Mineiro Aires stresses “there are too many urban rehabilitation projects that are mere cosmetic operations”, their potential to resist any kind of major earthquake completely untested.

Carlos Mineiro Aires adds that he is certainly not trying to be alarmist. The Order of Engineers has been trying to get the government to tighten regulations regarding ‘historic building gentrification’ for years.

The trouble is that with Portugal suddenly the poster child for touristic investment, warnings appear to have been lost in the euphoric stampede.

Entrepreneurs have been essentially racing to tart up old buildings in order to “sell them on for absurd prices”, particularly in Lisbon.

Warned Aires, unwitting buyers may “have no idea that what they are buying has no (earthquake) resistance”.

The problem goes back to what social media commentators dub a “simplex law” brought in during the last government, in 2014.

The “exceptional and temporary regime applicable to the rehabilitation of buildings” does not cover anti-seismic resistance, and thus a scenario already fraught with uncertainty has been allowed to become even more vulnerable.

Stirring things further, Mineiro Aires adds that “no-one should be under the illusion that a well-calculated anti-seismic structure can resist all demands. There are always damages”.

But what his sector considers vital is that “norms and legislation more in line with the reality of the potential risk that Portugal faces” are brought in – and fast.

Aires warnings followed what national media was calling this year’s “abnormal level of seismic activity”.

Starting early last month, the country has had a string of low-density rumbles, the largest of which – measuring 4.9 on the Richter Scale and being felt for hundreds of kilometres – came northeast of Arraiolos on January 15.

Since that tremor – described as the most sizeable on-land quake for 20 years – the same location has entered what experts call “a seismic crisis”.

Then came news from the Azores, in the early hours of Monday morning: another “seismic crisis” was underway, this time on the volcanic island of São Miguel.

Despite all the sophisticated equipment, no expert appears able to predict where all this underground activity will lead.

It could all blow over and ‘settle down’, or the country could be approaching another major quake on the scale of the one that shaped the country’s history in 1755.

There is no point in alarmism, say official sources, but as civil engineers continue to stress there is also no point in hiding heads in the sand.

Azores crisis could last days or months: 300 shocks in less than 24 hours

With surprisingly little being said in the media about the seismic crisis around Arraiolos, a great deal has been written about the crisis on the island of São Miguel.

It took hold in the early hours of Monday morning, with over 300 shocks being registered in less than 24 hours.

Miguel Miranda, a geophysicist and president of sea and atmosphere institute IPMA, dubbed it a “seismic crisis” that could last “days or months”.

As we went to press on Wednesday, the largest shock had registered 3.6 on the Richter Scale two days previously.

IPMA seismologists agree that the sheer number of quakes is ‘not normal’, though the issue is simply one of a “volcanic fault that is moving” – and that is perfectly normal.

It doesn’t herald a “catastrophic scenario”, said one interviewed by SIC television on Monday, but then again, no one can be sure what it all means.

Certainly, the local people of São Miguel are remaining sanguine. “We are used to this,” they tell reporters.
Needless to say, official warnings have been posted, and people are being advised to stock up on essentials, make sure they have a good first aid kit and accept that they might have to be “autonomous” for a 24-hour period if things get any worse.

Why Arraiolos?

Público has been speaking with geophysicists about the country’s unusual level of land-based seismic activity, only to hear that in the end it is perhaps not that unusual at all.

Quakes around Arraiolos, for example, have happened before as the town famous for its handmade rugs and carpets sits on top of a ‘fracture zone’ between two tectonic plates (the African and Eurasian).

Mourad Bezzeghoud, a geophysicist with the Institute of Land Sciences at Évora University, says the current activity will help “identify the geological fault in the area” which appears to slide horizontally along the Earth’s crust.

“We already have an idea,” he said. “But we are not sure.”

Rumbles around Arraiolos are continuing, as are tremors around Monchique, in the Algarve (to a much lesser extent).

But the ‘highest’ newsworthy activity remains in the Azores where experts explain that underground volcanoes add to the mix.

The line followed by all São Miguel’s tremors runs between the “Volcano of Fire and the Congro fissural volcanic system”.

The island itself is at the junction between what is called the American plate and the Eurasian and African plates.

But if one can read between the lines of all the news stories being generated, the density of quakes in all areas appears to be reducing.

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