Glossary

Saffir-Simpson Scale

The Saffir-Simpson scale ranks cyclones from Category 1 to 5 by sustained wind speed. Category 1 starts at 119 km/h, Category 3, called major, at 178 km/h, and Category 5 above 252 km/h.

It only accounts for wind. A low-category cyclone can be very deadly because of rain or storm surge. Live Atlas cyclone pages cover every storm that reached Category 3 since 1950.

Examples on the Map

• Tropical Cyclones Since 1950
• Hurricane Katrina (2005)

Other Definitions

• Tectonic Plate
• Subduction
• Mid-Ocean Ridge
• Transform Fault
• Fault
• Earthquake, Epicentre and Hypocentre
• Magnitude
• Intensity (Mercalli Scale)
• Aftershock
• Tsunami
• Active Volcano
• Stratovolcano
• Shield Volcano
• Caldera
• Volcanic Explosivity Index (VEI)
• Pyroclastic Flow
• Lahar
• Hotspot
• Tropical Cyclone, Hurricane, Typhoon
• Aurora and Kp Index