Geologic Time Scale

Over the past few days, a couple of my classmates and I created a digital geologic time scale of the Earth’s history. We used a Google image to illustrate just how large our planet’s time scale is. The amount of time you need to spend scrolling through the document represents the amount of time that passed between key events in the past. In order to get the most out of the experience, please click on this link: Geologic Time Scale.

Once you do that, find the magnifying glass icon at the top of you screen in the toolbar, click on the icon, and then scroll over the time scale. Click over the time scale approximately three to five times, select the mouse cursor icon in the toolbar, and then scroll through it at your leisure.

I definitely learned a lot by completing this project. It is very difficult to visualize exactly what 4.6 billion year looks like. This time scale served as a wonderful visual aid. It really helped put thing into perspective. I was surprised by the fact that humans have only been on this planet for a relatively short period of time. I was also intrigued by the fact that other complex life forms are a fairly recent addition in the grand scheme of the Earth’s time scale. This time scale really helped me develop a clearer understanding - I hope it is able to do the same for you.

The geologic time scale can be viewed through an analogy as well. Take a cross country road trip for example. The timeline of the Earth could be represented as a road trip where one drives from the east coast to the west coast. The origin of the Earth would be when I start my adventure in Bucks County, Pennsylvania (just outside Philadelphia), the oldest known Earth rocks would have formed as I reach Pittsburgh and the Ohio state border (approximately a six hour drive from my house), the appearance of algae and bacteria would occur once I arrive in Indiana, early shelled organisms would form as I approach Chicago, the beginning of the Jurassic period would begin as I cross over the Mississippi River, the Rocky Mountains form as I cross over the Rocky Mountains, and modern humans start to appear as I dip my toes in the Pacific Ocean. To better visualize this analogy, please refer to the map of the United States below.

Image Citation:

Map -http://www.worldmapsonline.com/images/academia/murals/academia_us_physical_mural_lg.jpg