This survey discovered the existence of the causeway leading from the site to the bayou.
Since 2004 the survey has discovered 400 potentially hazardous objects with a diameter greater than 100 m.
Recent surveys have discovered new populations of this species.
An international survey would probably discover some 500 new Earth-crossing objects each month, the team said.
A quick survey discovered a speedwheel of the more powerful type.
A subsequent survey in 2009 discovered even earlier parts of the town and recovered additional pottery.
In 1955 a survey discovered that repairs would be necessary in five years at a cost of £2 million.
The survey also discovered a strong need for organized day-care.
But the surveys also discovered that more people owned nets than actually used them.
A survey of more than 4,000 people conducted when the Timeline was first announced discovered that over 50% said they were worried by it.