CA Rev. 51'244'2021 Review Questions Answer the following questions. 1. Review the diagram on page 11. Why is anomaly V not included in your calculations? 2. According to your data, which anomaly has the fastest estimated rate of sea-oor spreading? 3. Between which two plates is the rate of seaoor spreading greater? 4. Why did many scientists reject Wegener's hypothesis of continental drift? 5. Explain how seaoor spreading provides an explanation for how continents move across the surface of the planet. 6. Think back to your answer to the question from page 5 \"What do you think Earth's continents will look like 225 million years in the future?\" Revise your answer using evidence from the lesson. CA Rev. 5/24/2021 Table 1 Cocos-Nazca Plates Anomaly I Anomaly II Anomaly III Anomaly IV (Use line A) Measured the distance across 0.5 cm 9.0 km anomaly on the map (cm) 0.3 km 0.4 km Scale conversion distance 125 km across the anomaly (km) 300 km 425 km 950 km Scale distance across the 12,500,000 cm 30,000,000 cm 42,500,000 cm 95,000,000 cm anomaly converted to cm Age (years) of Anomaly 5,000,000 yrs 5,000,000 yrs 5,000,000 yrs 5,000,000 yrs Average Seafloor Spreading 2.5 cm/yr 3.0 cm/yr 2.8 cm/yr 4.8 cm/yr Rate (cm/yr) of Anomaly Table 2 Pacific-Nazca Plates Anomaly I Anomaly II Anomaly III Anomaly IV (Use line B) Measured distance across the anomaly on the map (cm) 0.3 cm 0.7 cm 1.2 cm 1.7 cm Scale conversion distance 370 km 700 km 1,200 km 1,760 km from across the anomaly (km) Scale distance across the 120,000,000 cm 176,000,000 cm anomaly converted to cm 37,000,000 cm 70,000,000 cm Age (years) of Anomaly 5,000,000 yrs 5,000,000 yrs 5,000,000 yrs 5,000,000 yrs Average Seafloor Spreading 7.4 cm/yr 7.0 cm/yr 8.0 cm/yr 8.8 cm/yr Rate (cm/yr) of Anomaly Adapted from Simon-Waters, Barbara. The Race Is On... With Seafloor Spreading! N.p.: Deep Earth Academy: Consortium for Ocean Leadership, 2007. PDF.CA Rev. 5/24/2021 Seafloor Age (Ma) Gulf of I II III IV V IV Mexico 5 10 15 20 250 km 500km Mexico III Carribean Sea III IV A II IV Clipperton Fault Zone IV II III III III IV Cocos Plate IT II 0.5 cm B II V Pacific Plate III Nazca Plate IV Directions: 1. Along line A, use the centimeter side of a ruler to measure the distance for the width of each anomaly (I, II, III, IV), then record each measurement in the first row of Table 1 on the following page. Anomaly I has been completed for you as an example (refer to the arrow along line A in the diagram). 2. Use the scale on the map to convert each of the measurements into kilometers. Record this distance in the second row. Anomaly I has been completed for you as an example. 3. Convert the distance of kilometers into real-world centimeters using the following conversion. Write your answer in the third row. Anomaly I has been completed for you as an example. 1 km = 100, 000 cm 4. Calculate the average rate of seafloor spreading by dividing your measurement from row 3, by the age of the anomaly in row 4. This answer will be in centimeters-per-year (cm/yr). Write this in row 5. Anomaly I has been completed for you as an example. 5. Repeat steps 1 through 4 using line B on the map to calculate the rate of seafloor spreading between the Pacific and Nazca plates. Record these measurements in Table 2