This year’s field party among the lupins at Lake Tekapo. From left to right (back row): Robert Citron, Jim Karner, Jon Friedrich. Front row: Lauren Edgar, Daniela Hernandez, Erin Gibbons, Minako Righter.

Hi everyone,    this is yet another post that’s mostly a photo-dump.

When the team found out two days ago they’d have the full day off Wednesday (their Wednesday, not mine in the US),  they rented a car for a day trip to Lake Tekapo,  about 3 hrs drive SW of Christchurch.  It’s about 3 am their time on Thursday as I write this,  so I don’t know yet if they’ll be in the air today.

Tentmates Lauren and Erin with Lake Tekapo and the alps in the distance.

In te reo Māori , Takapō means “to leave in haste at night”.  Legend says the lake (and the other finger lakes dotting the Mackenzie Plains below the Southern Alps) was dug by Rākaihautū with his magic stick, “filling them with food for his many descendants” (from Wikipedia)

Minako and Daniela look longingly at the southern alps. No, you two, you do not have time to go exploring over there.

Of course to us geologists, lakes like Tekapo have interesting non-mythical origins.  The southern Alps remain glaciated today,  but at the last glacial maximum (about 15k years ago) those glaciers spread eastward across the Mackenzie,  carving a few very nice valleys along the way.  A channelized glacier pushes a lot of moraine out in front of it, and the terminal moraines that result  make for very nice dams as the glaciers recede and melt, leaving finger-lakes like Tekapo as a relatively consistent souvenir of the most recent ice ages globally.

That’s funny, they don’t LOOK dangerous….. 

Lupins are beautiful flowering plants that LOVE loose, coarse, aggregate glacial moraines,  and in the 40’s they were both purposefully and accidentally (escaping from garden) spread around the margins of the lake.   The result is an amazing springtime display that brings tourists to Lake Tekapo-    but like all invasive species, there is a cost.  The lupins spread aggressively and their quick-spreading roots stabilize the soil, meaning the normally braided glacial outflow streams become more channelized, unable to distribute floodwaters over broad, constantly-changing courses as they normally do.  This in turn makes flooding more likely and more common downstream.  As the memes go,  another example of pretty but not without negative consequences.

There you go- an update and a geology lesson all at once!    Please join me in wishing for the group to leave in haste, at night (or maybe just very early morning)………

Oh, and if anyone wants a post about possible Maori visits to Antarctica,  email me and beg.

-Ralph, who clearly has a thing about invasive plants.