Post date: Mar 04, 2013 5:49:16 PM
Next Media - Sinkholes typically form in karst landscapes where acidic ground water runs into the bedrock, dissolving the rock while creating cavities and caves that can collapse.
Sinkholes may trap surface drainage from standing or running water, but they may also occur in high and dry places.They are a natural occurrence, but can also be caused by human influences. People building homes, stores or retention ponds on fragile land can cause sinkholes to form.
The pumping of water from aquifers lowers the water table, which can also accelerate the creation of sinkholes.
In urban areas, sinkholes can occur from breaks in water mains or from sewer collapses.
SOURCES:
Tampa Bay Times
http://www.tampabay.com/news/publicsafety/sinkhole-swallows-part-of-seffner-home/1277042
Pennsylvania Department of Environmental Protection
http://www.portal.state.pa.us/portal/server.pt/community/sinkholes/10637/what_causes_a_sinkhole_/554362