One of Alaska's most populated cities is bracing for potentially catastrophic flooding as a basin dammed within the Mendenhall Glacier has started to release water.

Sections of Alaska’s capital city are bracing for the arrival of what could be record floodwaters due to rainwater and snowmelt flowing downstream from a basin dammed by the Mendenhall Glacier.

Glacial outburst floods aren't a new phenomenon in Alaska, but climate change is scrambling the geography of risk.