2024 ice tsunami in Yukon River tore through forest, altered riverbed

In 2024, an extraordinary ice-driven flood, termed an “ice tsunami”, raced along the Yukon River with such intensity that it uprooted hundreds of trees and stripped sediment from the riverbed. The event occurred during a cold season when thick ice cover suddenly broke apart, sending massive sheets downstream at high velocity.

Satellite imagery and on-site surveys reveal zones where fast-moving ice slabs gouged into riverbanks, removing both soil and rooted vegetation and leaving deep scours along the channel edge. In certain reaches, up to 10 meters of riverbank collapse was documented, along with terraces of exposed bedrock previously hidden under sediment.

Researchers describe this as more than a typical spring breakup; the sudden and forceful breakup propagated as a wave of ice fragments that acted like solid projectiles, capable of exerting dynamic pressure comparable to flood currents. Unlike normal ice jams or gradual thawing, this event initiated a shock wave effect, ice fragments collided and conveyed energy downstream, amplifying destructive potential.

Ecological consequences were severe. Uprooted trees fell into the river, altering flow patterns and creating debris jams. Riverine habitats that supported riparian vegetation and fish spawning grounds were disrupted by channel shifts and disturbance to substrate layers. Sediment mobilized by the event was transported far downstream and deposited in new configurations, changing local bed morphology.