It is called the Earth's ORBIT around the Sun.
The steep walled depression surrounding a volcano vent is called the crater. In dormant volcanos, these may fill with water and become crater lakes.
Most volcanoes and earthquakes occur around the Pacific Ocean basin in a roughly horseshoe shaped ring called the Rim or Ring of Fire. This is where the seismic activity is most intense due to the movement of the tectonic plates.
The major branch of volcanoes is Geology.
The Ring of Fire
a circular depression in the ground caused by a meteoroids is called a crater
The rare phenomenon you're talking about is called a calderas.Caldera is the term given to large depressions associated with volcanoes that form when volcanoes explode or collapse into the earth.
Crators? If that's what you mean by circular depression.
Caldera.
A circular depression that forms when a magma chamber empties is called a caldera. It is a large volcanic crater made from the collapse of a volcano's mouth.
A circular depression caused by underground erosion is typically called a sinkhole. Sinkholes can form gradually over time as underground voids or caves collapse, often leading to sudden and unexpected ground subsidence.
Volcanic crater.
the distance around a circular region is called circumference
dissolution sinkhole.
The steep walled depression surrounding a volcano vent is called the crater. In dormant volcanos, these may fill with water and become crater lakes.
The most volcanoes occur around the Pacific Ocean, in an area called the Ring of Fire.
The type of sinkhole that shows a circular depression over longer periods of time is called a "cover-collapse sinkhole." This type of sinkhole forms gradually as the ground surface slowly subsides into the underlying void, resulting in a depression that may continue to grow over time.