The creator of Christchurch's online 'earthquake map' explains its mechanics and its wide appeal around the world.
Environmental Health Officers collecting air readings outside Map World, on the corner of Manchester and Gloucester Streets.
Photograph captioned by BeckerFraserPhotos, "173 Gloucester Street".
Photograph captioned by BeckerFraserPhotos, "173 Gloucester Street".
Photograph captioned by BeckerFraserPhotos, "267 Manchester Street".
Photograph captioned by BeckerFraserPhotos, "The north-west corner of Manchester and Gloucester Streets (Map World). Extensive frontal collapse of the Gloucester Street frontage during the 13 June 2011 earthquake".
Photograph captioned by BeckerFraserPhotos, "Intersection of Gloucester and Manchester Streets (north-west view)".
A photograph of cars on Manchester Street which has been crushed by falling rubble. Bricks and other rubble from the earthquake-damaged shops above are scattered across the road in front. The word "clear" has been spray-painted on the side of the cars.