Archive for July, 2019

Tree Corps Visits the Tree Ring Lab

July 11th, 2019

Tree Corps visits the Wooster Tree Ring Lab. Tree Corps is a program run out of the Holden Arboretum designed to provide training to the arboriculture workforce in the Cleveland Area. It is funded by the Cleveland Foundation and this is the second year the group has visited Wooster. We all learned a lot from each other and everyone got to core some of the oaks on campus with the end of assessing tree health and age.

The group discusses the information that can be derived from the tree-ring record. This black oak shows outward signs of deterioration, however inside it is solid. In terms of management, the location of the tree with respect to foot traffic,  balanced with other pressing tree issues across campus, all need to be considered when assessing the possible removal of this tree.

Nick extracts a core from the oak and discusses the reasons for the various discolorations of the wood.

Josh Charlton (class of 2019, purple shirt) was visiting the lab and offers some advice in coring – thanks Josh for your help.

 

 

 

 

 

We also spent some time coring pin oaks on campus. Great fast growing trees – the group mounted up the cores and analysis of the tree rings is underway. Thanks to Tree Corps for making it down to the lab, we look forward to following the future progress of the group in arboriculture.

The week leading up to international field work

July 6th, 2019

Wooster, OH – In the week leading up to field work, Team Geochemistry was frantically trying to “put out fires” and clean up loose-ends.

The “fires” started first thing Monday morning, when a leak in the geochemistry lab caused the ceiling to collapse. Fortunately, the students and cleaning staff were quick thinking and all ended well.

Next, we tried to wrap up our petrology classification project, which involved lots of microscope work. Classifying minerals in the microscope was more challenging than we expected, and we still have more work to do when we return from the field.

Finally, we had to gather our field gear, double-checking that we had everything we needed. Undoubtedly, there will be something that we forgot.

Even with the frantic pace of the week, we still made some time for an ice cream (or two!). It was the Fourth of July holiday, after all.

Team Geochemistry in currently en route to Iceland for some field work. We’ll be reunited with Marisa, our teammate from Dickinson College, along with Dr. Ben Edwards and three other Dickinson students. Dr. Shelley Judge, from Wooster, is also joining us for this field excursion. Look for updates from the field late next week!

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.