When Heimdal shattered the Bifrost, the ripples were felt in every realm and caused extraordinary events to occur. On Vanaheim, the aftershock caused the dormant Volcano close to Stroya to awaken and erupt so violently it turned the land around it to cinders, covering the land around it in a blanket of ash, killing those in the immediate area instantly.
The sky carried ash for two years before clearing. It has been leaking lava ever since, creating fire rivers and hot springs. The sea also rose and disconnected the mainland into two islands. The land bridge that was once between between them is now submerged deep under water, taking villages and part of Vanaheim's history with it. The rise also cut of much of the outstretched coastlines, turning them into smaller islands.