Scientists monitoring the evolution of earthquakes in southern Evia call for time and patience.[/B] At least 140 earthquakes have been recorded since the 4.8 Richter on Tuesday morning, while the 5 on the evening of the same day created concern in the scientific community which is facing a very "unexplored" seismic area. On the one hand, the many earthquakes create a very slight optimism because the energy that had accumulated in the fault is being released, on the other hand, no one excludes the unpredictable event of the occurrence of another strong earthquake after the 5 Richter.
"So far we have observed two things. The seismic sequence has a specific space that has been developed and is confined, that is, we have so far no epicentres outside this space and this is better than having a dispersion of epicentres. Also a lot of energy has been dissipated with all these earthquakes both with the ones above 4 Richter and the smaller ones. This shows us that the region is discharging. But what I want to emphasize is that we should not be in a hurry. We need to look at the seismic sequence and see how it unfolds. So we still cannot say with certainty that the 5 Richter is the main earthquake. If the seismic sequence decreases in terms of the number of earthquakes not in terms of magnitude then we will be able to draw more reliable conclusions," says protothema.gr the seismologist and deputy director of the Geodynamic Institute Vasilis Karastathis.
As reported by the Greek protothema.gr, what scientists observe and examine is the seismic parameter b. To explain that the so-called seismic parameter b, is one of the most important parameters in seismology and shows the rate of seismic activity either high or low which is an indication of whether we are in a pre-seismic stage or in normal evolution of the phenomenon. When the seismicity is normal then the parameter is 1. However, if the parameter b decreases below the value 1 then it means that we may have pre-seismic signals. At the moment the parameter b is just below one which means that a strong earthquake of up to 5 Richter or slightly larger is not excluded.
Yesterday in an interview with SKAI the seismologist and member of the Seismic Risk Assessment Committee, Gerasimos Papadopoulos stressed that the seismic activity started in the area on 25 October, but it had not been evaluated by seismologists as it should have been.
Yesterday in an interview with SKAI the seismologist and member of the Seismic Risk Assessment Committee, Gerasimos Papadopoulos stressed that the seismic activity started in the area on 25 October, but it had not been evaluated by seismologists as it should have been. While, he pointed out that he could not say with certainty whether the 5 magnitude earthquake on Tuesday night was the main one. However, he does not believe that a new earthquake could be much above 5 Richter.
"There is considerable uncertainty arising from specific scientific reasons. First, we don't have a complete knowledge of the area, we don't have a good knowledge of the fault, we don't know in the past if there have been strong earthquakes in the area and that doesn't help the estimates. Secondly, the seismic activity in this area started on 25 October with very many small earthquakes and this was unfortunately not properly evaluated by the community, I put myself in. And these very small earthquakes convey valuable information to us. So we need time to look at all this data and in a spirit of understanding. I have reiterated many times that this state has institutions that are mandated precisely to bring scientists together through their committees and discuss."
Regarding the possibility of a more powerful earthquake, the seismologist said that "we have two possibilities. Either it was the main earthquake and the major hazard has passed, or it may not have been the main one and there may be a somewhat larger one. I agree with Mr. Lekka that the area does not seem to have the potential to take us to six or six and a half, we have incomplete knowledge about the area but it cannot give such a big one."
Given that the area was not one of the "suspicious" ones, seismologists stress that the priority is to monitor the phenomenon in the coming days to draw safe conclusions. For their part, residents are preparing for a second night of agony. Although the damage to homes was not severe, many stayed awake Tuesday into Wednesday and others even slept in their cars.
[BR][BR]Some fifteen houses have been damaged, while the kindergarten in Zarakes where 12 children attend has cracks. "The cracks that have been made are basically joints between masonry and reinforced concrete," said the kindergarten teacher, Evdokia Sarantari, who added that the building will be checked by special teams before the children return. Scientists, however, recommend residents to avoid stone-built old buildings, and point out on the one hand that the aftershock sequence needs monitoring, because the area is uncharted and the fault that gave the two big tremors is as yet unknown. Moreover, they ask residents to be careful, avoiding places where crowds gather to avoid panic scenes following a new earthquake.
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