Caldera vs Crater
Volcanoes and volcanic activities are wonderful natural activities that pave the way for future relief features on earth. Vulcan was the Roman fire god who is believed to be behind the fire of the volcanoes. While studying vulcanology, students come across two terms caldera and crater that both refer to depressions made at the top of a volcano. Craters or depressions are formed when magma and lava erupt making an opening at the top. This article attempts to find the differences between caldera and crater; both are depressions made by volcanic activities.
A large depression made because of volcanic activity is called a caldera. It is the result of a large cavity created underground when a chamber of magma and lava gets emptied. This cavity creates pressure and the over ground rocks collapse to create a large depression. This large depression is called a caldera. A caldera is a circular crater with almost vertical walls. The central floor of the caldera is later filled by lava flows that take place subsequently. Thus, caldera is both a process as well as a feature that starts with the collapse of the overlying unstable rocks and gets completed with lava filling the floor.
Earlier, geologists believed that calderas were formed because of blowing away of the top of a volcano with rush of magma and lava upwards.
A volcanic crater is a bowl like structure at the top of a volcano around the opening that is used for eruption of magma and lava. This is a depression that is the result of sinking in of the rocks because of high pressure. Mostly it has the opening through which lava and ash flows upwards. The hot lava weakens the cone like structure and causes it to sink in to create a bowl like structure that is referred to as a crater.
There are also craters on the surface of the earth that are a result of the impact with meteors falling from space.
What is the difference between Caldera and Crater?
• A caldera looks like a volcanic crater, but it is actually formed when the overlying rocks collapse when a magma chamber is emptied creating vacuum below.
• A volcanic crater is a bowl like structure at the top of a volcano that has the opening for the eruption of lava and the ashes.
• Thus, a caldera is a special type of crater.
• A crater is formed by sinking of the top of the volcano as lava weakens the rocks. On the other hand, a caldera is formed when the overlying rocks collapse to fill an emptied huge chamber of magma.
• When a caldera gets filled with water after some time of its formation, it is called a crater lake such as the one in Oregon.