Memories of Christchurch before earthquakes destroyed much of the central city are being forgotten, a local historian says.

University of Canterbury Professor Katie Pickles said memories of the pre-quake Christchurch were fast fading as more of the city's iconic buildings and landmarks were demolished.

"Many Christchurch landmarks have been demolished to make way for new buildings in what is becoming an exciting city," she said.

"But we have never been a demolition city before, with hard hats, high-viz, cranes, and wrecking balls. This is what Cantabrians see and hear on a daily basis. Memories of the past pre-quake city are fading.'"...