The case has provoked outrage in the international scientific community, with some commentators warning that any convictions would dissuade other experts from sharing their expertise for fear of legal retribution.
Prosecutor Fabio Picuti has asked for jail sentences of four years for each defendant for failing to alert the population of the medieval town of L'Aquila to the risks, days before the 6.3-magnitude quake killed 309 people.
All seven were members of the Major Risks Committee which met in the central Italian city on March 31, 2009 -- six days before the quake devastated the region, tearing down houses and churches and leaving thousands homeless.
The bright blue, classroom-sized temporary tribunal in L'Aquila -- built on an industrial estate when the town's historical court was flattened in the quake -- was crowded with lawyers, advisors and international media.
Four of the the defendants were in court, as well as a small group of survivors.
"This is going to be a historic verdict. I hope they will be found guilty. They held a position of responsibility and it would make sure scientists pay more attention in the future to their advice," said lawyer Wania della Vigna.
"They were not expected to predict the earthquake but they were expected to alert people to the risks," said Vigna, who represents 11 plaintiffs, including an Israeli student who died when a student residence collapsed.
Aldo Scimia, whose mother was killed, said he hoped "the state will do its duty. Their main duty is to provide security and they failed."
In his summing up, Picuti said the experts had provided "an incomplete, inept, unsuitable and criminally mistaken" analysis, which reassured locals and meant many stayed indoors when the first tremors hit.
The government committee met after a series of small tremors in the preceding weeks had sown panic among local inhabitants -- particularly after a local resident began making unnerving unofficial earthquake predictions.
Giampaolo Giuliani was making predictions on the basis of radon gas levels with a home-made system and his methods have not been scientifically proven, but they were enough to cause jitters among residents.
Italy's top seismologists were called in to evaluate the situation and the then vice-director of the Civil Protection, Bernardo De Bernardinis, gave press interviews saying the seismic activity in L'Aquila posed "no danger."
"The scientific community continues to assure me that, to the contrary, it's a favourable situation because of the continuous discharge of energy," he said.
The claim that shocks discharge energy and reduce quake risks has been widely disputed and the scientists deny having told Bernardinis anything of the sort.
The prosecution has accused Bernardinis of using the meeting to calm the population -- he famously advised residents to relax with a glass of wine.
-- "Medieval criminal law" --
Government lawyer Carlo Sica, who has called for the seven defendants to be acquitted, said the minutes from the March 31 meeting were not valid as evidence because they were only written up and signed following the April 6 earthquake.
"They are not guilty of anything, the earthquake's no-one's fault," he said.
Alessandra Stefano, lawyer for one of the scientists, Gian Michele Calvi, said ahead of the hearing: "There shouldn't be any chance of a conviction."
Filippo Dinacci, lawyer for Mauro Dolce and Bernardo De Bernardinis, also criticised the charges last week as something out of "medieval criminal law."
The case sparked outrage in the international scientific community when the charges were brought against the geophysicists in 2010, with many complaining that they were merely scapegoats and warning against putting science on trial.
Over 5,000 members of the scientific community sent an open letter to President Giorgio Napolitano denouncing the trial against colleagues for failing to predict an earthquake -- a feat widely acknowledge to be impossible.
But Picuti insists the point is not whether they could have predicted the quake but that the government-appointed experts were supposed to evaluate the risk and advise a large population in a town with fragile, ancient buildings.
The seven include Enzo Boschi, who at the time was the head of Italy's national geophysics institute, Giulio Selvaggi, head of the INGV's national earthquake centre in Rome and Franco Barberi from Rome's University Three.
The other scientists on trial are Mauro Dolce, head of the Civil Protection's seismic risk office, Gian Michele Calvi, head of the European centre of earthquake engineering and Claudio Eva from the University of Genoa.
About 120,000 people were affected by the April quake, which destroyed the city's historic centre and medieval churches as well as surrounding villages.
As well as the manslaughter charge, the seven have been accused of reckless endangerment, causing buildings to collapse with serious injury to people.