Gravity causes ice to deform slowly and slide over the ground. Movement rates vary from centimetres per day to much faster surges. Cracks form where the brittle surface cannot bend as quickly as deeper ice.
What we found
A glacier is a flowing body of accumulated snow and ice. Under pressure, deep ice can deform plastically, while meltwater may reduce friction at the base. Stakes, satellites and radar allow scientists to measure motion. A single photograph makes a glacier look stationary, but time-lapse images reveal the flow clearly. The Ridbusters then compare the wording with the original sources, look for the conditions of each observation and check whether another explanation could fit. That turns a surprising headline into a trail a young investigator can follow: claim, test, result and remaining uncertainty. Gravity causes ice to deform slowly and slide over the ground.