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!

Sources/Usage: Some content may have restrictions. View Media Details

The EarthWord: Tephra

Definition:

• Tephra is the general name given to anything thrown into the air during a volcanic eruption. It can range from individual ash particles all the way to volcanic bombs.

Etymology:

• Tephra comes from the Ancient Greek tephra, meaning “ashes.”

Use/Significance in the Earth Science Community:

• The various types of tephra can have far-ranging impacts on the environment and human society. Ash clouds can reach the upper atmosphere, temporarily lowering temperatures and potentially interrupting air travel. Cinders can blanket nearby ecosystems and communities, causing health problems and damaging infrastructure. And volcanic bombs can very actively and directly damage infrastructure.

USGS Use:

• USGS studies all types of tephra and their effects as part of our Volcano Hazards Program.

Next EarthWord: It’s not just teens that like to rebel; sometimes it’s rock layers...

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.