Today…

1. Today… • Just a quick review • An exercise to think a bit about volcanoes and tectonics • Warning systems • Perhaps the lava flows video

2. Results of the “voting” • Tornadoes and atmosphere • Hurricanes • Tsunami • Wildfires • Impacts and extinctions/coastal hazards/climate change (tied) No promises, I’ll see what I can do (some material is covered better in the book than other stuff)

3. Your clickers, please

4. The exam Wednesday was • Like the first one -- okay, but surely not easy • Way harder than the first one • Way easier than the first one • Saved by my 3x5 card…

5. We looked at a couple of boundary types that have volcanoes. These are… • Transform and convergent • Convergent and divergent • Divergent and transform

6. Are there commonly volcanoes along transform boundaries? • Yes • No

7. Why not (pick your best answer)? • No source of mantle melting (like subduction) • No pulling crustal slabs to bring asthenosphere to the surface (like spreading) • No other way to get asthenosphere close to the surface • Volcanoes get pulled apart along the strike-slip fault faster than they can grow

8. Why is there no asthenosphere near the surface in a transform zone?

9. To do, today, with at least one other person • State why “Iceland” and/or “Hawaii” are neither island arcs nor continental arcs: what critical ingredient is missing?

10. 2.Iceland and the Big Island of Hawaii are both hot-spot volcanoes. Why is Iceland so much larger than the Big Island? • to answer this you need to look at a map (coming up) to convince yourself there’s a difference in size • to answer this you need to look at the tectonic map, either in your book or in the front of the room • what happens at hot spots? • what are the tectonic settings of the Big Island and Iceland? • why is Iceland so much bigger?

11. (this slide is just so you can see the difference) ~ 135 km ~400 km Iceland Hawaii

12. Some terms you need to know • Extinct: completely dead • Dormant: sleeping, could become active • Active: any time, starting tomorrow • Frequency:magnitude concept

13. Alert-level systems • Most commonly used is the color scheme • Newly minted “common terminology” scheme

14. GREEN: Volcano is in a normal, non-eruptive state. Or, after a change from a higher level: Volcanic activity considered to have ceased and volcano reverted to its normal, non-eruptive state. YELLOW Volcano is exhibiting signs of elevated unrest above known background levels. Or, after a change from a higher level: Volcanic activity has decreased significantly but continues to be closely monitored for possible renewed increase. ORANGE Volcano is exhibiting heightened unrest with increased likelihood of eruption. Or: Volcanic eruption underway with no or minor ash emission. RED Eruption is forecast to be imminent with significant emission of ash into the atmosphere likely Or: Eruption is underway with significant emission of ash into the atmosphere.

15. NORMAL Typical background activity of a volcano in a non-eruptive state. Or, after a change from a higher level: Volcanic activity considered to have ceased, and volcano reverted to its normal, non-eruptive state. ADVISORY Elevated unrest above known background activity. Or, after a change from a higher level: Volcanic activity has decreased significantly but continues to be closely monitored for possible renewed increase. WATCH Volcano is exhibiting heightened or escalating unrest with increased potential for eruptive activity. Or: A minor eruption is underway that poses limited hazards. WARNING Highly hazardous eruption underway or imminent.