Q Sea Ice & Earthquakes Sea Ice Trends For this section, you will be doing the Environmental Analysis activity on page 249 of your textbook, and answering questions 1-5. The Activity below is adapted from your textbook. The National Snow & Ice Data Center monitors sea ice coverage and concentration. The Sea Ice Index is calculated from this coverage to assess the change in sea ice compared with the 30-year average. Go to http://nsidc.org/data/seaice_index (Links to an external site.)Links to an external site.. Answer the questions below. 1. When did Sea Ice index data collection start? 2. The "median ice edge" line on the map represents the 30-year median ice extent. Is the current ice cover more than or less than the 30-year median? 3. View the "Monthly Sea Ice Extent Anomaly" graph, and click on "About this graph." How is the monthly ice extent anomaly calculated? 4. Examine the Monthly Sea Ice Extent Anomaly Graph (click on it to make it larger). When was the last year that the sea ice extent anomaly (for the current month) was greater than the 1981-2010 mean sea ice extent? 5. Given the 1981-2010 mean sea ice extent labeled near the bottom of the graph, calculate the current sea ice extent (show your work). Hint: Subtract the current sea ice extent anomaly from the 1981-2010 mean. 6. How does the extent anomaly graph compare with the temperature anomaly graph of Figure 4-34 (Links to an external site.)Links to an external site. in your textbook? Earthquakes Go to the USGS Earthquake Hazards Program's Latest Earthquakes (Links to an external site.)Links to an external site. map. 7. How many 2.5 or greater magnitude earthquakes have occurred in the continental U.S. in the last day? Note: You may want to count the earthquakes on the left hand side column to get an accurate count. 8. Where did the strongest of these earthquakes occur and what was its magnitude? 9. Using the Option settings, switch to 30 Days, Magnitude 4.5+ U.S.. How many 4.5 magnitude or greater earthquakes happened in the continental U.S. in the last 30 days? Where did they occur? 10. Using the Option settings, switch to 30 Days, Significant Worldwide and zoom out to the World. What can you say about the location where most of these earthquakes occur? Where did the two strongest of these earthquakes occur and what was their magnitude? 11. Zoom to Hawaii. How many significant earthquakes have occurred in Hawaii in the last 30 days? Hawaii is not located near a plate boundary. Why do you think it has experienced significant earthquakes in the last 30 days? PreviousNext