4. Describe the changes occurring that are causing volcanoes to form in: a. the Great Rift Valley b. Iceland. 5. Determine whether the following statement is True or False. Very few active volcanoes occur at or near plate boundaries. ANALYSE AND APPLY 6. Explain how the scale of the changes happening in Iceland is different from the scale of change happening in the Great Rift Valley. 7. Discuss how hotspots lead to volcanic activity. Use examples in your analysis. 8. Explain why a volcanic eruption like the one in FIGURE4 forms in Iceland. Deduce what is happening to the plates. 9. Draw what you imagine Iceland will look like many thousands of years in the future after further rifting. Provide new names for each of the smaller islands. Determine in which direction, and towards which continent, each island will drift. Describe key changes. Answers and sample responses for this topic are available online.
LESSON 14.10 Investigating topographic maps – Mount Taranaki, New Zealand
LEARNING INTENTION By the end of this lesson, you should be able to: • investigate Mount Taranaki in New Zealand and interpret a topographic map • use grid references to pinpoint locations on a map.
New Zealand’s Mount Taranaki is named after the M̄aori terms tara , meaning ‘mountain peak’, and ngaki , meaning ‘shining’ (because the mountain is covered with snow in winter). Mount Taranaki is 2518 metres high and is the largest volcano on New Zealand’s mainland. It is located in the south-west of the North Island (see FIGURE1 ). Mount Taranaki was formed 135 000 years ago by subduction of the Pacific Plate below the Australian Plate. It is a stratovolcano (composite cone) — a conical volcano consisting of layers of pumice, lava, ash and tephra. Mount Taranaki is symmetrical, looking the same on both sides of a central point. It is the only active volcano in a chain in this region. The other volcanoes were once very large but have been eroded over time. The summit of Mount Taranaki is a lava dome in the middle of a crater that is filled with ice and snow. The mountain is considered likely to erupt again. There are significant potential hazards from lahars (mudflows containing volcanic debris), avalanches and floods. A circular plain of volcanic material surrounding the mountain was formed by lahars (see FIGURE3 ) and landslides. In the past, some of these flows reached the coast. The volcano’s lower flanks are covered in forest and are part of the national park. There is a clear line between the park boundary and surrounding farmland.
TOPIC14 Geomorphological processes and hazards
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