Test your knowledge with these top questions!
Which flat area beside a river regularly floods?
Floodplains form from sediment left when rivers overflow, which makes their soil fertile.
Which fault ruptured to cause the 1906 San Francisco earthquake?
The rupture ran about 296 miles along the San Andreas, shifting the ground by up to 32 feet.
Which preventive practice burns undergrowth to reduce wildfire fuel?
Removing dry undergrowth ahead of time leaves less fuel for an uncontrolled wildfire.
In which season did the Nile River historically flood Egypt?
Ethiopian summer rains swelled the Nile each year before the Aswan Dam brought the floods under control.
Which US air base was evacuated before Mount Pinatubo erupted in 1991?
Thousands of US personnel left Clark days before the blast, which later buried the base in ash.
Why can volcanic ash clouds shut down jet engines in flight?
In hot engines, ash particles melt and coat parts with glass, cutting airflow and stalling the engines.
Which ocean surge floods coasts during a hurricane?
Wind and low pressure push seawater ashore as a surge, which causes most hurricane flood deaths.
What sudden change in ocean water can signal an approaching tsunami?
Exposed seafloor happens when the wave trough reaches shore first and pulls water outward.
Which force pulls loosened rock and soil downhill in a landslide?
Gravity constantly tugs slope material downward, and rain or quakes can release the mass so it slides.
In which island nation did Krakatoa erupt in 1883?
Krakatoa sits in the Sunda Strait between Java and Sumatra, part of Indonesia's volcanic arc.