The three signs a volcano is about to erupt
A state of emergency has been declared in southern Iceland after another volcanic eruption on the Reykjanes Peninsula - the fourth since December.
But it can be notoriously difficult to know when an explosion might happen, especially when a volcano has been dormant for many years.
However, scientists can look for particular signs and trends to make predictions.
Video produced by Sanjana Bhambhani and Howard Timberlake
