(originally published 4 Aug 2023)
An uphill view of the Davis-Ward icefields
It’s been a while, folks. We missed you SO MUCH!!!!
After three seasons cancelled due to pandemics and related logistical shortfalls, ANSMET stands poised to return to the field this December. We’ve been shy about sharing the details so far, and we apologize for that. But it’s simply because even today we still feel like the rug could be pulled out from under us at any time- like it was last year in early summer, and the year before that too. At risk of jinxing ourselves, ANSMET leadership now feels pretty solid about the upcoming 2023-2024 season, so it’s time to pull back the curtain and fill you in on the details about what we have planned.
Our target for the coming field season is fairly predictable. The Davis-Ward icefields, which sit between and around the Davis Nunataks and Mt. Ward in the headwaters region of the Beardmore Glacier, have been a repeated target of 7 previous expeditions, resulting in the recovery of over 3000 meteorite specimens. After all that work we’re within striking distance of finishing our systematic searching efforts. That’s a significant priority for us, and anytime we finish at a field site (usually after extending that target date several times) it’s a landmark occasion for us.
Formal planning for the 23-24 season truly began years ago. When our last field season ended in January of 2020, we had assumed we’d be back in about 10 months, so we left a substantial amount of gear and fuel carefully cached at our campsite. That makes a tremendous amount of sense, of course- every bit of stuff cached becomes something we don’t need to fly back out to Davis-Ward for the next season, a huge logistical savings. That cache is proof we were planning to revisit Davis-Ward in the next season, 2020-2021. But of course history had other plans, and when we next see that gear it will have been almost a full 4 years since we promised we’d be back soon.
The good news of course is that our plans for the coming season are VERY mature- they’ve been refined and carefully hammered into shape for years, far longer than a “normal” season. There’s “bad” to temper the good, however; the maturity of our plans has been offset by reductions in NSF’s abilities to support deep field parties and almost complete overturn among the support staff that actually makes our work happen. Relationships with supporting staff, program officers, contractors and other entities that we’d carefully cultivated for years are gone, wiped out by a stinkin’ little virus. On the other end of the pipeline, our grant funding also expired during the pandemic, so new proposals had to be written, submitted, reviewed and (thankfully) funded. In a nutshell, while we know exactly what we want to get done at Davis-Ward and exactly how to do it, paving the path to the site has been (and remains) a challenging work in progress. We are excited, cautious and hopeful.
The plans
The 2023-2024 ANSMET field season will (hopefully) follow the pattern established by our most recent seasons, but starting about a week later than usual. A team of 8 field party members (details forthcoming in a future post) will depart the US in the first few days of December, arrive in McMurdo 3-5 days later, and get put into the field about 7-10 days after that (nominally mid December). One of our mountaineers and a partner will be sent out to the Davis Ward campsite by Twin Otter several days before that to groom a skiway that will allow the use of a larger Basler aircraft for our main group put-in. That advanced team will also have the daunting task of digging out a cache of supplies that’s been exposed to three Antarctic winters.
Progress map of Davis Ward icefields. Green dots represent meteorite finds from the last field season (2019-2020). Small dots mark the tracklines of one GPS-equipped snowmobile. Only a small sliver at the north end of the main DW ice tongue remains to be systematically searched, along with some of the icefield across the moraine to the north. Significant work also remains in the moraine girdling that ice tongue as well.
Once the team is complete at Davis-Ward, meteorite recovery becomes the priority. Our first goal for the season is completion of systematic searching; but in the case of Davis-Ward, it’s not as simple as a limited number of traverses. The remaining blue ice has a fairly dense covering of wind-blown rocks disguising the meteorites mixed in; and the remaining moraine searching is of course even slower work, with field team members trying to distinguish the dark-chocolate chunks (the meteorites) from the semi-sweet bits (the Ferrar Dolerite). Weather and logistical delays could (as always) play a big role in the coming season; but we’re hopeful that one side-effect of our late start, further past the Antarctic spring, will be fewer early-season windstorms.
If things go really well, sometime in early January the systematic searches will be completed and a mission accomplished vibe will settle across Davis-Ward. But rather than settle down on the infamous Davis-Ward “Beach” for a well-deserved late-summer break, the field team is scheduled to pack up and move on to the nearby Dominion Range Main icefield. That potential move will include the first snowfield traverse we’ve done in about a decade, with a Twin Otter ferrying heavy or high-volume gear (ANSMET’s famous “Flying Traverse”). We’re very confident in the ability of our mountaineers to guide us safely along the route (particularly given that satellite imagery of the site is amaze-balls), but NSF’s field safety folks (who don’t know us well) remains a little skeptical. Put simply, we’ve never forgotten how to do this and we have a long history of performing these traverses safely; the areas we operate in are an order of magnitude less risky than an alpine glacier or the Ross Ice Shelf. But that kind of historical perspective isn’t something NSF easily hangs on to, and like the rest of the world they’ve grown more and more risk-averse.
Satellite mosaic showing both the Dominion Range Main icefield and the Davis Ward icefields. Our overland traverse would basically go straight from the lower triangle to the upper one, a 30 km, 6-8 hour trip through relatively benign terrain. the hardest part of the trip is the start; getting packed up and nosing our way through and around the Davis Nunataks and associated blue ice.
The new target, the Dominion Range Main icefield, was first explored in 1985, during the same first-order reconnaissance-focused season that discovered Davis-Ward and several other sites in the region. The potential for the Dominion Range Main icefield to bear a significant meteorite concentration was confirmed during a more detailed reconnaissance effort in 2003. There’s a lot of blue ice there, maybe twice as much area as at Davis-Ward; but the setting is very different. Whereas Davis-Ward is a deflating ice tongue walled-in on 3 sides, Dominion Main is blue ice that is slowed and stranded by a sidewall mountain range as it tries to empty gradually into the Beardmore Glacier. Based on what we know about icefields (which may be extensive, but admittedly is still mostly anecdotal), this setting implies wide variations in ice velocity, ablation rates and surface age across the exposed surface, which fits with the accompanying variations in the concentration of meteorite samples seen previously. Suffice it to say we know the meteorites are there, and have ferreted-out a few of their favorite hiding spots; but our understanding of the site as a whole is woefully incomplete. January 2024 will be the first time we’ll go there with a focus on systematic recovery of meteorites, and we’ll just have to wait to see whether it’s truly a site for the ages.
I’m going to close here with a quick shout-out to the planetary materials community, ExMAG and others. The annual ExMAG meeting is taking place as I write this; and community support for ANSMET was abundantly clear. ExMAG and others need to remind NSF’s Office of Polar Programs how much they value ANSMET as a critical part of NASA’s mission, and help NSF understand they’re obligated to support ANSMET even if the project’s goals don’t address their own, narrower mission. Without your support, the 2023-24 season might indeed not be taking place, so we are extremely grateful. Thank you! And with your continued support (and reminders to NSF that you like us), perhaps ANSMET once again can recover specimens on a consistent, yearly basis.
-Ralph, on the charmingly quiet campus of Case Western Reserve University.