Canterbury University Law student Sam Johnson hit on the idea after learning that lessons had been cancelled for a week after the 7.0-magnitude earthquake hit New Zealand's second largest city on Saturday.
"On Saturday night I saw all these Facebook groups like 'I survived the quake, lets party' and 'buy a T-shirt, Christchurch quake 2010' had sprung up," the 21-year-old told AFP.
"I thought 'come on guys, surely we can do something more positive than that and do something positive for the community'."
Johnson set up the group "student volunteer base for earthquake clean up", calling on his peers to get out and help clear the debris littering Christchurch after New Zealand's most destructive quake in almost 80 years.
"The response has been overwhelming," he said, describing how 300 people turned up to help on the first day and almost 1,900 have registered to join the group on the social networking website.
The volunteers were equipped with shovels, wheelbarrows and buckets, then set to work in groups of 20 around the city, liaising with emergency services authorities.
"We've had residents break down in tears when we go around," Johnson said.
"Their gardens are covered in silt up to the top of the daffodils and they've found it difficult to cope. They just appreciate a bit of help."
He said it was not just university students who were prepared to get their hands dirty.
"We've had schoolkids too, it's great to see the little tykes in there getting stuck in," he said.
"It's hard physical work, people have been going home exhausted."
Aside from people in Christchurch volunteering, the website group has also receive more than 5,000 messages of support from around the country and as far afield as Spain and Britain.
"What a wonderful thing you guys are doing, wish I could just up and come down to Christchurch and help you all out," wrote Tanya Williams of Rotorua, in New Zealand North Island.
There were also offers to help Christchurch residents experiencing computer problems, drive volunteers to sites and do the laundry of households still without water.
"Me and my three kids 11, 9 and 6 wanna help somewhere, they have their shovels ready, where needs help??," wrote local woman Kirsteen Adam.
Johnson said the initiative would have been impossible without social networking technology.
"Maybe you could have done something with email but you couldn't have reached these numbers," he said.
"If people phone up and log their interest in volunteering at a call centre they can feel they've been overlook, with Facebook, people can involve themselves directly.
But Johnson said the outbreak of community spirit could have its drawbacks for Christchurch's student population.
"It's certainly ruined our reputation for just drinking and being quite useless," he said.