We would like to express our thanks to the following for their contributions to this site:

Center for Disease Control and Prevention (CDC),
Colorado Geological Survey (CGS),
Florida Department of Environmental Protection (DEP),
Geological Survey of Alabama (GSA),
Illinois Natural Resources Geospatial Data Clearinghouse, Illinois State Geological Survey, (Sinkhole Areas (an indicator of karst terrain); accessed March 18, 2013),
Indiana Geological Survey (IGS),
Indiana Geographic Information Council (IGIC),
Iowa Geological Survey (IGS),
Kentucky Geological Survey (KGS),
Land Information New Zealand / Linz Data Service
Minnesota Geological Survey (MGS),
Missouri Spatial Data Information Service (MSDIS),
National Geophysical Data Center / (NGDC/WDS) Global Historical Tsunami Database, Boulder, CO, USA.
   (Available at,
New Jersery Department of Health,
New Jersey Department of Health and Senior Services,
NOAA/National Weather Service,
Nova Scotia Canada, Department of Natural Resources (DNR),
Occupational Safety & Health Administration, U.S. Department of Labor (OSHA),
Pennsylvania Spatial Data Access (PASDA),
United States Environmental Protection Agency (EPA),
U.S. Department of the Interior | U.S. Geological Survey,
University of Minnesota (UM),
Water and Environmental Research Institute of the Western Pacific Island Research & Education Initiative,
World Nuclear Association (WNA),
Wyoming State Geological Survey (WSGS)