The geography of our planet presents diverse geographic accidents that make and determine the particularities of each terrain, in as much, a geographic depression is an area, an area of the relief of our planet that is characterized by being at a lower height with respect to the regions that surround it.
Basically what produces a depression is the subsidence of the land in question and it can be due to several causes. Subsidence is a common reason for depressions that consists of the vertical subsidence of the land corresponding to a sedimentary basin due to an excavation process and the consequent weight of the sediments. The ground is totally destabilized and the ground is then depressed vertically at a rather slow rate.
Different is what happens with the collapses of the land in which the speed of the subsidence is certainly phenomenal and in a short time the area is totally depressed.
After this collapse, the area affected by the depression can be literally covered by water, several meters from the water surface, that is to say, below sea level, or failing that, it can be completely at the sail of the contiguous areas that they boast a higher altitude. Some very characteristic examples of this that we comment on are the Caspian Sea, which is the maximum depression of the European continent and on the other hand the Great Basin in the western part of the United States of America.
The size of the depressions can be very few meters in diameter or they can be a huge depressive structure that can even have a continental level.
Depressions can be the result of various factors, among which are: the movements that occur in the tectonic plates and that have a direct impact on the geological material; when it finishes accommodating, for example, a mountain relief; the oscillations that occur in the soil or in groundwater, whether due to natural causes or human intervention; a fault in the geological structure, among others.
