
The initial fumarolic vent formation was caused by overpressured rock which then collapsed to allow gases and what people refer to as non-juvenile or material not from fresh magma to escape. A fumarole is a vent which emits steam, gas or potentially other volcanic material at high temperatures, generally ranging from 100 to 1000 degrees celsius. The openeing of this vent was caused by the breakdown of the rock material, typically, but not exclusively, volcanoes in humid regions such as Costa Rica are more susceptible to collapse. This is caused by acidic water eroding and weakening rock, which, when the correct pressure is applied is liable to collapse. This process can be sped up by a constant degassing volcano such as Turrialba currently.