Archive for July 5th, 2019

Columbia Bay’s Emerging Landscape

July 5th, 2019

I had the distinct pleasure of working in Columbia Bay, Alaska for ten days along with researchers Drs. Tim Barrows from the University of Wollongong – Australia, Peter Almond of Lincoln University, New Zealand, and Wooster’s own, Nick Wiesenberg.

Tim with the retreating West Branch glaciers in the background.

Peter with the spectacular backdrop of the calving glaciers in the West Branch.

Nick reclining in the old growth mountain hemlock forest overlooking Lake Terentiev – sure to be a classic tree-ring record of past climate.

Logistic centered on travel in an aluminum skiff. Captain Peter took the helm and Nick kept us off the ice, which on some days was easier than others (see below).

One of the primary objectives was to sample boulders on moraines and bedrock surfaces to determine the timing of glacial changes in Columbia Bay. Tim and Nick sampling for cosmogenic dating on a surface outside of the Little Ice Age limit.

Sampling a boulder that is well vegetated. Note the bug nets – we did notice the bugs.

Peter is a soil scientist and he dug pits on most surfaces we studied; here a well-developed spodosol is revealed. It had been years since we have dug soil pits and I was amazed. Future trips will include soils work and a stout spade.

The geomorphology was interesting at all turns – here is a beach berm that likely formed when the glacier, now 25 km away, was nears its maximum during the early decades of the 20th century. Note the trees growing on the surface; a nice project for dendrogeomorphology.

In 1909 Tarr and Martin observed the then expanded and soon to be advancing Columbia Glacier – the top panel is their photograph taken in 1909 with the Columbia Glacier looming over a remanent forest. The lower panel is a photo from the same location in June of 2019.

We were also fortunate to work on Heather Island (great thanks to the Tatitlek Corporation for permission to visit the Island). The upper panel is the Tarr and Martin 1909 photograph from near the summit of Heather Island and the lower photograph was taken in June of 2019.

The photo above was taken in June of 2014 – note the location of the calving glacier in the background relative to the photo below taken in June of 2019.

The active ice in the west arm of Columbia Bay is now 4 tributary glaciers – a dramatic change in less than five years.