A simple concept which explaining caldera forming is pushed by volcanic lava and gas throughout the crack beneath the surface. This earth driven power will throw a big blast and rearranging earth surface shape by leaving circular form as we know it as caldera. Recent study pointing that there are alternative concept of caldera forming process. The two most recent examples of this new concept happened in 1912 at Philippine's Pintatubo and in 1912 at Alaska's Katmai.
Geoscientists believe that new type caldera forming is driven by gravitational force when there is an escalation of weight on the volcanic surface as a process of vacating the magma chamber. Unstable surface sometimes lead to a collapse and forms a depression. Bardarbunga in Iceland is a volcanic sites that used by scientist to observe this style since it is known as "relaxed" volcano. Several earthquakes are also recorded around Bardarbunga Caldera due to "ring fault" at boundary of the caldera.
wired.com/2016/07/explosive-eruptions-arent-way-form-caldera/
Geoscientists believe that new type caldera forming is driven by gravitational force when there is an escalation of weight on the volcanic surface as a process of vacating the magma chamber. Unstable surface sometimes lead to a collapse and forms a depression. Bardarbunga in Iceland is a volcanic sites that used by scientist to observe this style since it is known as "relaxed" volcano. Several earthquakes are also recorded around Bardarbunga Caldera due to "ring fault" at boundary of the caldera.
wired.com/2016/07/explosive-eruptions-arent-way-form-caldera/