Release Date:

It’s not just something you run into on a golf course-it’s this week’s EarthWord!

EarthWords is an on-going series in which we shed some light on the complicated, often difficult-to-pronounce language of science. Think of us as your terminology tour-guides, and meet us back here every week for a new word!

USGS map displaying potential to experience damage from a natural or human-induced earthquake in 2017
USGS map displaying earthquake hazard. (Public domain.)

The EarthWord: Hazard


  • In everyday terms, hazard is usually used to describe something as a threat or an obstacle, but in the earth science fields, hazard actually refers to an event that has the potential to cause harm.  


  • Hazard comes to us from the Old French hasard, which referred to a game of chance played with dice.

Use/Significance in the Earth Science Community:

  • To the earth science community, a hazard, a risk and a disaster are all different. Geologic hazards are natural phenomena capable of inflicting harm to people or property. Risk, on the other hand, is the statistical potential that such a hazard will actually lead to loss of life or property. Disasters happen when a hazard does, in fact, inflict harm to people or property.

  • For example, Town A and Town B are right next to the same earthquake fault. They have the same earthquake hazard. But they don't have the same risk, because Town A has buildings built to withstand earthquake ground shaking and Town B does not. If you are Town B, you have two things you can do to reduce your risk of being hurt or killed in an earthquake: you can build to withstand earthquake ground shaking, or you can move. If an earthquake occurs that affects Town B, and lives or property is lost, that earthquake would be considered a natural disaster.


  • USGS is responsible for monitoring numerous natural hazards, particularly earthquake, landslide, and volcano hazards.

  • The USGS Earthquake Hazards Program is part of the National Earthquake Hazards Reduction Program, established by Congress in 1977. We monitor and report earthquakes, assess earthquake impacts and hazards, and research the causes and effects of earthquakes.

  • The USGS Landslides Program studies the causes of landslides, where they might occur, and how big they might be to help protect U.S. communities from the dangers of landslides.

  • The USGS Volcano Hazards Program monitors and studies active and potentially active volcanoes, assesses their hazards, and conducts research on how volcanoes work in order for the USGS to issue timely warnings of potential volcanic hazards to emergency-management professionals and the public.

Next EarthWord: Which sounds more dangerous, lava or mud? The answer may surprise you...

Hungry for some science, but you don’t have time for a full-course research plate? Then check out USGS Science Snippets, our snack-sized science series that focuses on the fun, weird, and fascinating stories of USGS science.