Reading the Signs: teacher key

Natural Disasters, grade 11 edition, written for 11th grade. Every disaster leaves signs that scientists can read: a pattern in a radar image, a slope on the ocean floor, a number from a fault. See how those signs turn into warnings.

Read the book. Print this page for the key.

Questions and answers

1. Why does the U.S. East Coast face a different tsunami source mix than the Pacific Rim?
   • It has no ocean
   • Its coasts are not near subduction zones (answer)
   • It has no earthquakes
2. What does a Tornado Vortex Signature show?
   • A region of intense concentrated rotation on Doppler radar (answer)
   • A tornado's exact wind speed
   • The year of a tornado
3. Are EF Scale wind speeds measured?
   • Yes, directly
   • Only at night
   • No, they are estimates based on damage (answer)
4. Why can the Gulf Coast see higher storm surge than Florida's southeast coast?
   • It has no hurricanes
   • Its ocean floor deepens gradually offshore (answer)
   • It has no tides
5. What is a storm tide?
   • High tide at the same time as a storm surge (answer)
   • A hurricane's eye
   • A kind of rain
6. Does a Tornado Vortex Signature guarantee a tornado?
   • Yes, always
   • It lowers the probability
   • No, but it strongly increases the probability of one (answer)

Words

• seismic: about earthquakes
• subduction: plate sinking
• mesocyclone: rotating updraft
• meteotsunamis: weather-made waves
• polarization: wave direction
• levees: flood walls