Every spring cracks emerge in the frozen Gulf of Bothnia around the Unesco-protected islands of the Merenkurkku archipelago in western Finland. The archipelago, also known as Kvarken and situated off the coast of Vaasa, has been a Unesco World Heritage Site since 2006, drawing tourists to its scenery and wildlife. The landscape, featuring thousands of islands, is largely the result of the last Ice Age. Photographer Olivier Morin has produced a series of aerial images of jetties on the frozen coast.