posted on Jul, 13 2010 @ 11:25 AM
The consensus among my fellow geologists and geographers is that the incidence of sinkhole activity is increasing primarily because of rapid urban
development in areas that are typically replete with collapsed limestone cavities in the bedrock beneath.
Some of these areas extend for hundreds of square miles. It's like building on top of a giant sponge with a thin covering. The thin soil covering
is mostly open space as well, filled with either air or water, and on top of this is frequently constructed heavy concrete buildings, roads, and other
structures (and their contents).
Thus, where there was merely open land and a thin covering of loose soil (for many thousands of years), there are now the sprawling infrastructure and
activity of humanity. Consequently therefore, and increasingly, some of these structures can not be supported by the thin membrane of the 'sponge
bubbles' directly beneath them and, periodically but inevitably, collapse into the cavity below.
Yes, these cavities collapse all on their own, with nothing built above them, [quite frequently in fact], but again the worlds population is growing
and spreading (as are our observing instruments and technology), and so it is not unusual that more of these 'natural' disturbances are observed,
'YouTubed", and made known via the MSM.
The natural evolution of such geologic landscapes is to eventually collapse and erode the entire surface material into the lower elevations below
(mass wasting), resulting in a landscape known as Karst Topography, an unusual, but beautiful intermediate step that leaves many small steep hills
like pimples all over the land -like this area in the former Yugoslavia:
I'm as open to alternative explanations, of course, but my only caution is to try and look at all possibilities, and then attempt to draw reasonable
conclusions without sensationalizing the subject.
Incidentally, the Earth is indeed experiencing many internal dynamic processes, -which ebbs and flows on geologic time scales; not human ones. So, an
exceptionally strong series of earthquakes, sinkholes, volcanoes, etc., correspond with tectonic activity that bursts forth now and then as the thin
broken eggshell crust of the planet floats on top of the molten material below.
Every few thousand years or hundred thousand years or million years (mere winks of the eye, geologically) one or more of these eggshell chunks bump or
slide or rub against each other. On and near the boundaries of these cracks there are immense forces at work. The consequence of these forces are
the thousands of earthquakes experienced around the planet every day, the 500 or so active volcanoes on the planet in various stages of eruption, and,
yes, the settling and lowering of the continental surfaces, via sinkhole activity, as the Earth constantly tries to reshape itself back into a smooth
ball in spite of all these forces happening to it.
Stay curious my friends...
[edit on 7/13/2010 by Outrageo]