Domes

And my quest to understand...

Have you ever heard of katabatic winds? Maybe you’ve heard of the geologic term ‘dome’? You could google either of these terms and get a much more succinct answer than the one I’m about to give you. But to start this post off with an immediate geo-ecological digression, I’ve been hung up on what ‘domes’ are here in Alaska. There’s Murphy’s Dome and Ester Dome. It first piqued my interest because it seems to me these domes are the only way to get on top of something (anything?!) here in Fairbanks. But are they glorified hills, big hills, small mountains? Most importantly, can I run up them? Calling them domes simultaneously tickles and confuses me. What specific qualities do these hills hold to make someone call them DoMES? (DOMES, dOMes, domES. “Yeah dude! Gonna get some mad domage today yeeahahahaha!”)

When I asked my advisor, he told me they were hills of loess deposited by winds. Loess is a geologic term for glacial dust or “…fine rock flour…”, German in origin. Glaciers and ice sheets grind up rocks into varying sizes and shapes. When the ice retreats, it leaves behind these rocky sundries- sometimes boulders dubbed ‘erratic’s and sometimes this loess stuff. Anyways, I wasn’t satisfied by Knut’s vague-ish answer. I reiterated my question to Sam and Tako, who are generously housing me in their guest basement at the moment. Sam is a geologist and Tako is a geobotanist. These winds Knut mentioned are none other than katabatic winds. Katabatic winds are the grandfathers of chinooks. Massive amounts of ice cool the air. Cold air sinks because it is dense. This air is extra dense. Ice sheets and glaciers are sloped. Now combine everything and imagine dense cold air moving down sloped land or ice. Et voila! Wind! By the time these winds have reached the newly deglaciated, loess-filled land they are seriously gnarly. Now we have insane ‘rock flour’ dust storms that are depositing sediment across interior AK over hundreds of thousands of years, creating massive loess dunes. This phenomenon still happens today to a much lesser extent. And frankly, I think it’s sick!

“But wait! Emily are you seriously about to say domes ARE NOT ancient loess dunes?”

Yes…sorry! Knut was, ahem, WRONG. These specific domes don’t even fit the geologic definition of dome per se! They’re NOT EVEN REAL DOMES! The “domes” themselves are granitic intrusions that, due to their metamorphic qualities, erode at a much slower rate than everything around them. As the loess blew in on the katabatic winds, it deposited around the “domes”, but not on top of them. When did these intrusions form relative to this ice-sheet business? I don’t know! Again, why don’t I just google this shit? Because it wouldn’t be half as fun as asking three incredibly intelligent, educated locals about the natural history of Alaska. I wouldn’t have been loaned a book called ‘After the Ice: The Return of Life to Glaciated North America’ by E.C Pielou. And I wouldn’t have read about katabatic winds, or the fact that we’re currently in an interglacial period, and a bunch of other wicked facts about ice sheet positive feedback loops etc. etc.

So thanks for your patience. I know you’re probably reading this because you want to know how I’m doing. I’m doing fine! So much has happened since I’ve arrived, I don’t even know where to begin. I’ve picked bog blue berries. I met Sarah James, an Neets’aii Gwich’in elder, activist, and environmental leader. (She’s a living legend). I survived orientation and my first week of school. I’ve watched Fairbanks turn from summer to fall and seen hundreds of Sandhill Cranes fly overhead. I’ve ran through bogs (known as wet trails here) and cursed. Anyways, call me if you need to know more. I am lonely and I miss Durango. If you made it this far in my post, thanks for following along!