ES-117-2A-77 Natural Disasters (Online

Background

Impact Craters

Among the most conspicuous, abundant, and widespread phenomena in the early Solar System was cratering of planetary surfaces as the new planets were bombarded with remnant planetesimals, asteroids, and other rocky and cometary debris scattered throughout the system.

Fig. 1. Google Earth image of Manicouagan Crater, Quebec, Canada.

Assignment Instructions

1. Earth was not immune from these impacts, though much of the geologic record of these events was long ago recycled on our geologically active planet. Google Earth will take you to a number of the best-known, most thoroughly documented impact sites on our home planet. Just enter the coordinates below into the query bar of Google Earth (you can also use Google Maps which some students find easier to use) and you will be transported to the locations of great catastrophes in Earth’s history.

1. Visit each of the craters above. Describe the appearance of each crater? Is the shape well pronounced? Is there evidence of erosion? What erosion mechanisms are obviously at work in and around this crater?
2. Search for other impact sites on your own. Prepare a list a minimum of the 3 craters you found describing the nature of each. If you can find specific information about each crater, you can include that as well.

Complete a report for this week's lab.

YOU MUST USE THE FOLLOWING LAB REPORT TEMPLATE: LAB 7 REPORT TEMPLATE

Your lab report should be 2-3 pages in length and MUST contain the following:

• TITLE - Lab Title
• INTRODUCTION - Introductory paragraph(s) stating the purpose of the lab and covering all concepts, ideas, and definitions covered in the lab.
• PROCEDURES - Overview of the lab procedures and data collection.
• DATA - Presentation of data collected (tables, images, graphs, etc...)
• QUESTIONS - Answer to all questions posed in the lab (if any).
• CONCLUSION - Concluding paragraph(s) in which you discuss the results of the lab and what you've learned from the experience.

Here are some additional links to related sites.

1. Wikipedia entry on Impact Craters
2. Interactive Map of Impact Sites
3. Meteor Crater, Arizona, USA
4. Impacts Happen
5. The Torino Scale
6. The Palermo Scale
7. Impact Risks

NOTE: a fascinating web site estimating the probability of impact and impact effects of collisions with known objects crossing Earth’s orbit. Hyperlinks explain probabilities in ‘down-to-Earth’ language.