Monthly Presentations

The Central Oregon Geoscience Society holds regularly scheduled monthly presentations on the 4th Tuesday of each month, from September to November, and from January to May. All presentations are free and open to the public.


Please join us at:

Worthy Brewing (eastside location)

495 NE Bellevue Drive, Bend

In the Hop Mahal Room


5:30 pm social hour

7:00 pm presentation


COGS talk are free and open to the public -- all are welcome! Please join us for the social hour before the presentation.

Presentations are also live-streamed through Zoom. Please see the presentation details for Zoom registration links. Zoom presentations are recorded whenever possible, see the list of past presentations to watch recordings of past talks.



Visiting Scholar Presentations

Visiting Scholar presentations are scheduled during various times outside the regular monthly meeting schedule. Please check the schedule below for updates, or join the COGS email list for updates. To join the email list, go to the Join us page.



Upcoming Presentations

  • Does Volcanic Ash Fertilize The Globe?

    • 22 Sep 2026
    • 5:30 PM
    • Online and in-person at Worthy Brewing


    Does Volcanic Ash Fertilize The Globe?



    Hubert Staudigel

    Scripps Institution of Oceanography at the University of California in San Diego


    Volcanic soils are legendary for their fertility, and in particular volcanic ash is commonly considered as a potentially commercial use as a mineral fertilizer. The benefit of volcanic ash as a fertilizer appears obvious based on its nutrient contents but it is not clear whether, and under which circumstances this holds true. Staudigel will discuss the relationships between soil fertility and volcanic input into a soil through controlled greenhouse experiments that have shown that volcanic ash may result in a threefold increase in bioproductivity. This talk is based on a recent, freely downloadable paper published in the Journal Ecosphere (DOI: 10.1002/ecs2.70406) .



    Please join us at:

    Worthy Brewing (eastside location)

    495 NE Bellevue Drive, Bend

    In the Hop Mahal Room


    5:30 pm social hour

    7:00 pm presentation


    COGS talk are free and open to the public -- all are welcome! Please join us for the social hour before the presentation.

     All presentations are also live-streamed through Zoom. There will be a registration link at the top of this page as we get closer to the date of this presentation.


    Show details

  • Corridor of Cataclysm -- mapping the perilous geologic journey of the Owyhee River

    • 27 Oct 2026
    • 5:30 PM
    • Online and in-person at Worthy Brewing