Volcano of classifying magmatic volcanoes is by their frequency of eruption, with those that erupt regularly called active, those that have erupted in historical times but are now quiet called dormant or inactive, and those that have not erupted in historical times called extinct. However, these popular classifications—extinct in particular—are practically meaningless to scientists. They use classifications which refer to a particular volcano's formative and eruptive processes and resulting shapes. There is no consensus among volcanologists on how to define an "active" volcano. The lifespan of a volcano can vary from months to several million years, making such a distinction sometimes
Monvert Nature Park River Gorges National Park. The nature park has two main sections, the smaller visitors interpretation centre, and the nature walk over the larger natural area. The Visitors Centre, just off the A10, contains a display of the biodiversity, forests and invasive species of the country, as a basic overview. Behind the centre is the arboretum, where over 150 labelled endemic and indigenous species are grown on grassy slopes intersected with paths. Many are critically endangered or extinct in the wild. At the bottom of the arboretum is the fernery, where many of the island's critically endangered endemic ferns and orchids