GEOLOGY

Detailed explanation-1: -Changes to a volcano’s ground surface (volcano deformation) appear as swelling, sinking, or cracking, which can be caused by magma, gas, or other fluids (typically water) moving underground or by movements in the earth’s crust due to motion along faults.

Detailed explanation-2: -The magma rises and collects in chambers within the crust. As magma fills the chamber, pressure grows. If the pressure gets high enough, the magma can break through the crust and spew out in a volcanic eruption. Most explosive volcanoes occur above subduction zones.

Detailed explanation-3: -As the magma reservoir inflates, it pushes the overlying and surrounding ground up and out. Similarly, the ground around active volcanoes can swell (inflate) due to pressurization from magma below.

Detailed explanation-4: -Gas exsolution increases pressure in the magma, which can deform surrounding rock and the overlying ground surface, causing it to bulge upward. Conversely, gas escaping from magma lowers magma pressure, allowing the overlying surface to subside.

Detailed explanation-5: -As pressure falls within magma, the size of the gas bubbles increases greatly. These expanding gases exert an enormous force. When a volcano erupts, the force of the expanding gases pushes magma from the magma chamber through the pipe until it flows or explodes out of the vent.