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Keep up to speed with our Falkor research cruise with this latest seafloor syntax!

Image shows a bunch of tube worms in the deep ocean

Lamellibrachia sp. tube worms at a cold seep. Gulf of Mexico. The bodies of these and other organisms near the seeps eventually form new carbonate rock formations called chemoherms. Credit: Image courtesy of Expedition to the Deep Slope 2007, NOAA-OE.

(Public domain.)

From June 12 to July 3, the U.S. Geological Survey and Schmidt Ocean Institute will be conducting a research cruise off the coast of Oregon and Washington, hunting deep-sea bubbles and the creatures that eat them. While we post stories about our findings, we’ll also be posting little vignettes like these, in which we serve as your terminology tour-guides to the unusual and hard-to-pronounce words that dwell in the depths of deep-ocean science.

The WaterWord: Chemoherm


  • Chemoherms are carbonate rock formations that have built up around methane seeps from the bodies of creatures that live near the methane seeps and rely on them for food, either directly or by consuming the organisms that live off the methane.


  • Chemoherm is made up of chemo- and herm. Chemo- comes from chemistry, which itself comes from alchemy, which has uncertain origins. It seems to be a mix of an old name for Egypt, Khemia, and the Greek word khymeia, meaning “to pour out.” Herm, meanwhile, comes from the ancient Greek word herma, meaning “reef.”

Use/Significance in the Earth Science Community:

  • Chemoherms are significant geologic features on the seafloor and study of them can indicate what kinds of organisms were living around the methane seep that led to the creation of the chemoherm.

U.S. Geological Survey/Schmidt Ocean Institute Use:

  • USGS and SOI are collaborating on a research cruise off the coast of Oregon and Washington that will study methane seeps in a region known as the continental margin. It is likely that near these seeps will be chemoherms.

Next WaterWord: Bathymetry

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