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 occur inland on the continental plates due to the subduction of an oceanic plate, or at weak points in the oceanic plates where magma is being heated from below. They can occur anywhere there is liquid rock (magma) welling up into spaces in the rocks above them.