The Question:

Last summer, on a walk along Orca Road, I saw bubbles rising from a shallow pond near the Science Center. The ripples were fairly large. Another couple saw the same occurrence at the same spot. I was wondering if this could be methane gas or a small aquatic creature below the surface. 


The Answer:

That is an excellent question, Sharon! Katey Walter Anthony of UAF’s Water and Environmental Research Center (WERC) was able to help us answer this question. According to Katey, there is a lot of methane bubbling up around Cordova, including Orca Inlet, Eyak Lake, Eyak River, McKinley Lake, Saddlebag Lake, etc. Katey and her husband were able to map and sample many of the bubbling seeps in Cordova. They determined that gas coming up through the faults has a thermogenic (geologic) origin, like the natural gas associated with oil at Katalla. As you move away from the faults, the gas becomes a mixture of microbial and thermogenic methane.

This figure shows subcap seep methane stable isotopes in relation to faults in the Lake Eyak region of southcentral Alaska. This figure was taken from Walter Anthony et al., 2012. To read more about methane gas in Cordova, check out Katey Walter Anthony’s paper on Geologic Methane Seeps Along Boundaries of Arctic Permafrost Thaw and Melting Glaciers. DOI 10.1038/NGEO1480.  

We are currently seeking more questions from the community. If you have a scientific-related question, please email it to



Works Cited:

Walter Anthony, K. M., Anthony, P., Grosse, G., & Chanton, J. (2012). Geologic methane seeps along boundaries of Arctic permafrost thaw and Melting Glaciers. Nature Geoscience, 5(6), 419–426.