Geologic Hazards

Earthquakes - Learn about earthquakes and how they have affected cities and people.

Landslides A USGS fact sheet about landslides and events that trigger them.

Homeowners Insurance and Geologic Hazards Most policies do not cover geologic hazards.

Largest Hurricanes Are they determined by wind speed, value of damage, most deaths?

Volcanoes Articles about volcanoes, volcanic hazards and eruptions past and present.

Liquefaction occurs when water-saturated soil is severely shaken and loses strength.

Geology Tools - Hammers, field bags, hand lenses, maps, hardness picks, gold pans.

What Causes a Tsunami? Learn how plate motions trigger earthquakes and tsunamis.

Yosemite Rock Fall Photos A photo sequence of a rockfall and debris avalanche by Herb Dunn.

Asteroid Impact Craters! Zoom in on 50 of Earth\'s largest impact craters.

Expansive Soil Causes more damage than floods, hurricanes & tornadoes combined.

Volcanic Explosivity Rating volcanic eruptions based upon the volume of tephra ejected.

Most Powerful Eruption of the 20th Century - and most people have never heard of it.

Hurricane Names How are hurricanes named? Is your name on the list?

Abandoned Mines accidents take 20 to 30 lives per year. Many could be prevented.

World Record Lightning - This lake has more lightning than any other place in the world.

Largest Tsunami - The wave with the highest run-up was in Lituya Bay, Alaska.

Storm Surge can be the most damaging and deadly aspect of a hurricane.

Lightning Strikes Map - shows the worldwide distribution of lightning activity.

Atlantic Tsunamis Rare events that can cause damage and threaten millions of people.

Google Map of the San Andreas - Zoom in to see the fault trace plotted atop of a map.

Pacific Tsunamis This ocean is surrounded by plate boundaries, that can produce tsunami.

Indian Ocean Tsunamis Deadly tsunamis triggered by earthquakes and volcanoes.

Yosemite Rockfall Hazards have been mapped by the National Park Service.