At the innermost part of Stongfjorden, the landscape is characterised by several flat surfaces at different levels. These steps are not as clearly visible anymore, partly because of tall trees and houses. These steps are called terraces and are striking traces of former sea levels from the end of the last Ice Age up to the present day. They were formed by large glacial rivers flowing out from the ice, depositing sand and gravel in a delta at the river mouth in front of the glacier. Three distinct terraces lie at around 40, 29–26, and 12–10 metres above present sea level. They represent three different sea levels after the last Ice Age and thus show how sea level changed as a result of relative land uplift.
