The victims of the earthquake in L'Aquila have also been awarded between €40,000 to €450,000 ($52,000 to $584,000 Cdn), said freelance journalist Megan Williams.
Italian prosecutors say that the scientists gave inaccurate and incomplete information about whether smaller tremors before the April 2009 quake should have been grounds for an official warning.
The 6.9 magnitude earthquake left 309 people dead and injured more than 1,500 others.
Judge Marco Billi took slightly more than four hours to reach the verdict, the BBC reported.
In Italy, convictions aren't definitive until after an appeals trial, so it is unlikely any of the defendants would face jail immediately.
Charges 'unfair and naive', scientists say
Among those convicted were some of Italy's most prominent and internationally respected seismologists and geological experts, including Enzo Boschi, former head of the national Institute of Geophysics and Volcanology.
"I am dejected, desperate," Boschi said after the verdict. "I thought I would have been acquitted. I still don't understand what I was convicted of."
Another convicted defendant, Bernardo De Bernardinis, a former official of the national Civil Protection agency, said "I consider myself innocent before God and men."
During the trial, which began in September 2011, the defence had argued it is impossible to predict quakes. Seismologists have long concurred, saying the technology doesn't exist to predict a quake and that no major temblor has ever been foretold.
The chief executive of the American Association for the Advancement of Science (AAAS), a non-profit organization which publishes the journal Science, wrote a letter in 2010 to Italian President Giorgio Napolitano calling the charges against the experts' "unfair and naive".
"The basis for indictments brought by the local prosecutor in L’Aquila appears to be that the scientists failed to alert the population of L’Aquila of an impending earthquake,” wrote Alan I. Leshner, CEO of the AAAS and executive publisher of Science. "However, there is no way they could have done that credibly."
'They would have fled that night'
But prosecutors focused on a memo issued after a meeting of the Great Risks commission — a committee which the scientists were part of, and which evaluates potential for natural disasters — before the earthquake. The March 31, 2009 meeting was called because of mounting concerns about the months of seismic activity in the region.
Many much smaller earth tremors had rattled the area in the months before the quake, causing frightened people to wonder if they should evacuate.
According to the commission's memo, issued one week before the big quake, the experts concluded that it was "improbable" that there would be a major quake though it added that one couldn't be excluded.
Afterward, members of the commission gave reassuring interviews to local media stressing the impossibility of predicting quakes and that even six months worth of low-magnitude temblors was not unusual in the highly seismic region and didn't mean a big one was coming.
The BBC reported that prosecutors, in their closing statement, quoted one of their witnesses whose father died in the earthquake.
The statement described how Guido Fioravanti called his mother on the night of the earthquake, after the first tremor, the BBC said.
"I remember the fear in her voice. On other occasions they would have fled but that night, with my father, they told themselves what the risk commission had said. And they stayed."