A Sinking Feeling
Central Idea: Many people may not know about these but scientists think they may be happening more frequently. Specific Purpose: To inform the audience about what causes sinkholes, where they commonly occur, and what can you do to keep yourself safe from sinkholes.
I.The date is February 2, 2011, after a long wet winter in Levittown, New York a elementary school bus was making its way to school. The bus turned a corner when, bang! The wheel of the bus suddenly dropped several feet and tipped on it's side. The bus had hit a sinkhole. Thankfully no one was hurt, but a tow truck had to pull the bus out of the hole. II. Sinkholes can be one of the most devastating natural disasters if the hole is large enough. As the rock under large cities such as New York get older and more dissolves away more sinkholes could happen all the time. III. Through a lot of research and a preunderstanding of earth science I will inform you about these natural disasters, and give you a better understanding about what they can do. IV. All of you have probably seen a sinkhole on TV or heard about one on the radio, but in little small town Iowa we're pretty safe.... or are we. V. In this speech we will go through what causes sinkholes, where they commonly occur, and how to stay safe from sinkholes. Hopefully by the end of the speech you will have an understanding of sinkholes. (Transition: Why do sinkholes happen? Well in this next section I will tell you what the major factors are in sinkholes.)
I. Sinkholes can be very dangerous but before we find out where they occur most often we need to have an understanding about why they occur. A) The main reason sinkholes occur is Natural causation.
1) Karst Topography is what the geology is like in most places where Sinkholes occur. a) Karst regions have gypsum or limestone...