The Gambia has no migrating wildebeest, giraffes or any of the large animals commonly associated with Africa. However without leaving your hotel you can see a breathtaking variety of bird life, in addition to monkeys and lizards. Baboons and crocodiles can be seen nearby and then far up the river, hippos.
As the gasses collect in the magma chamber, the pressure rises. It is possible for the pressure to rise so much that the chamber cannot contain the magma and it erupts explosively. Some US Parks that have active volcanoes formed as the result of subduction related processes are: 1  Crater Lake National Park, OR.
Volcanoes can form in three geologic settings, all of which result in the melting of rock in the upper part of the mantle. The rock in the mantle is very hot but is kept solid under immense pressure. Some volcanoes form at divergent boundaries where two of Earth's tectonic plates pull apart. The crust is thin at these boundaries, reducing pressure on the mantle, allowing some melting to occur, forming molten rock called magma. This rises to the surface, forming volcanoes.