June 18, 2019

Cruise blog: Observing seafloor methane seeps at the edge of hydrate stability

Posted by larryohanlon

Four new updates from the ongoing cruise of the R/V Falkor

June 17 — The secret life of bubbles 

By Alex Demas

Footage from the Bubble Box. The paired cameras allow for a three-dimensional analysis of the bubbles. Credit: Tim Weiss, GEOMAR. (Courtesy of GEOMAR)

“Wait, stop, back up! There were bubbles back there!”

With a cry and dramatic gesture to the screen, GEOMAR scientist and shipboard bubble expert Jens Greinert grabbed all of our attention.

“Trust me, I’ve got a sixth sense for bubbles,” Jens assured us, or more specifically, ROV SuBastian’s pilot. And sure enough, after we performed the delicate navigation involved to make the ROV do a U-turn 1,500 feet below the surface, there they were – a silvery stream of bubbles wobbling up from the seafloor. [read the rest of the post here]


June 15 — The WaterWord: Methanogen

By Alex Demas

Bubbles of methane, also known as marsh gas, created by methanogens. (Image credit: by Chad Skeers (on Flickr) – https://www.flickr.com/photos/chadskeers/5467580395, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=41768193)Image credit: by Chad Skeers / CC BY 2.0

Definition: Although similar to the previous EarthWord, methanogenesis, this word is slightly different. It refers to the class of microbes that create methane. Once classified as bacteria, these microscopic organisms are now organized under the kingdom of Archaea, which are single-celled organisms. Methanogens can be found all over the world, in almost any environment.

Etymology: Methanogen is a shortened form of methanogenesis, which is made up of methane and genesis. Methane comes from the French word methylene, itself made up of the Greek word methy (wine) and hyle (wood). This is because methylene was detected in wood alcohol. Genesis, meanwhile, comes from the old Greek word genos, meaning “birth, descent.” [read the rest of the post here]


June 14 — Spinning a food web nearly three thousand feet underwater

By Amanda Demopoulos

Methane bubbles up from a cold seep in the Astoria Canyon.

The black of the mud makes for a stark contrast against the brilliant purple of USGS scientist Jennie McClain-Count’s gloves as she passes the sample from its tube to three freshly prepared bottles. The samples in her hands have just had a rather precipitous journey, rising from a depth of 850 meters (a little less than 2800 feet) to the wet lab of the R/V Falkor. Now, these sediments and other samples will be analyzed by Jennie’s capable hands. [read the rest of the post here


June 13 — WaterWord of the day: Methane seep

By Alex Demas

Methane seeping on the Virginia margin just shallower than the limit for gas hydrate stability. NOAA Office of Ocean Exploration and Research

Definition: Ever see a movie set at the bottom of the sea, and notice occasional streams of bubbles coming up from the seafloor? That’s what a methane seep is: A point where methane (a gas) escapes from the rock into the ocean above it. It is one of several types of ocean seeps where things like petroleum, carbon dioxide, or hydrogen sulfide leak into the waters surrounding them.

Etymology: Methane comes from the French word methylene, itself made up of the Greek word methy (wine) and hyle (wood). This is because methylene was detected in wood alcohol. Seep, meanwhile, comes from the Proto-Indo-European word seib, meaning “to pour out, trickle.” [read the rest of the post here