The Wooster Tree Ring Lab and Archaeology Day at the Wayne County Historical Society, Wooster Ohio

October 18, 2026 Greg Wiles Leave a comment

The College of Wooster Tree Ring Lab (WTRL) participated in Archaeology Day. It was a beautiful day exchanging views and data between archaeologists, historians, Wooster Earth Scientists and the public.

Li and Leo explain the extraction of local information from tree-ring in Wayne County that is relevance to the Settlement of Wayne County Ohio.

Local collectors, historians and Archaeologists from surrounding counties share their expertise.

Trees as witnesses was common theme and many of the participants grew up around the old growth on The College of Wooster campus as well as Cornerstone Elementary School campus, Browns Lake Bog, Barnes Preserve and Johnson Wood, all in Wayne County.Li worked with the younger participants assembling Tree Ring Lab necklaces (see lower right) and handing out stickers. Before the kids can get a necklace they needed to identify the species of the wood making up the necklace pendant. The log building in the background – the Naftzger cabin, has been dated using tree rings by the WTRL. Here is the report.

Nik shows the group a core from the oldest living tree in Ohio (so far discovered). It is chestnut oak from Stebbins Gulch, which is part of Holden Arboretum. He successfully identified his necklace as a

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Alaska, Uncategorized

GSA2026 Denver – Student Work

October 13, 2026 Greg Wiles Leave a comment

Four Wooster undergraduate students traveled to the Annual Meeting of the Geological Society of America in Denver for three days of presentations, networking and learning. They reported on preliminary results of their Independent Study thesis work.
Cheyenne gears up for some lively conversation – she has taken on the task of comparing Northern and Southern Hemisphere coastal tree-ring records aiming to better understand the role of the ocean-atmosphere system in the Pacific that is symmetric across the tropics.

Adam is looking at the signal in old growth (>250 years old) forests across Ohio that “witnessed” European Settlement in the early 1800s. This is a timely study coinciding with 250 Anniversary of the Nation.
Anika is reporting on a discovery that Western Red Cedar have a winter signal in their ring-widths – explaining this is a big part of her work. She is the first to report on the first red cedar chronologies developed from Alaska. Another first for the Wooster Tree Ring Lab.
Anna has taken on a study of lake cores and the interval in time that coincides with Settlement and changes in diatom communities over the past few hundred years in two lakes in the Sierra Nevada, CA.
Anna shares an inside diatom

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Ohio, Uncategorized

Updating The College of Wooster Oak Tree Ring Record

September 25, 2026 Greg Wiles

Guest blogger: Adam Wood
The Modern Climate Change course in the fall of 2026 (MCC26) took on the task of updating the campus oak ring-width tree ring chronology. It was last cored over a decade agoand is one of he few sites of Ohio’s remaining old growth (those trees greater than 250 year old). Not only is 2026 the 250th anniversary of the nation, it is also the first year of the College campus as an arboretum – the Abbey Arboretum.

Nick Wiesenberg (center) directs the coring operation.
Coring Trees on Campus:
Home to several old growth white oak trees, The College of Wooster has “tree witnesses” to the last 250 years of changing climate and land use. Old growth trees, specifically those of the white oak (Quercus alba) have been found to date back to the late 1600s CE in Ohio. Using dendrochronology the MCC26 class were able to count the individual tree rings in each tree core and assign calendar years to each growth band and combine this data with previous year’s efforts to update the college’s tree ring chronology to 2025.
Methodology:
On September 28, 2026, the MCC class with the help of COW technician Nick Wiesenberg used increment borers to core the

https://woostergeologists.scotblogs.wooster.edu

Ohio, Uncategorized

Master Dating of a Master’s Panel Painting

August 26, 2026 Greg Wiles

A first for the Wooster Tree Ring Lab (WTRL) – dating a 17th century painting from the Rembrandt Studio in the Netherlands.
Nick Wiesenberg, technician in the lab (right) and the owner of the painting James Elchlinger from Zora Advisory Group. The painting is titled “A Scholar in His Study” possibly painted by Gerbrand van den Eeckhout of Rembrandt Van Rijn’s studio. This panel painting was on an oak panel that had over 240 rings. The mission was to measure the ring widths and then to use dendrochronology to assign calendar dates to each ring by comparing (aka crossdating) ring-width measurements to a master chronology that is calendar-dated. A tree-ring date would help validate the authenticity of the painting.

A close-up of the painting.

The first step was to prepare the surface of the oak panel by carefully sanding the top of the painting to be sure that the wood cells within each ring were visible. Dr. Hernán Medina (standing; Wooster Spanish Professor) and Anika Knowles (lower right; Wooster Earth Science/Spanish major and Alaska Tree Ring worker) look on.
The oak panel is made of three panels glued together, and is only about 5 mm thick; the back of the painting is bolstered by a “cradle”

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Uncategorized

ESCI Senior Independent Studies 2026 – Lynnsey Delio

May 7, 2026 Greg Wiles

Advised by: Dr. Wiles
Abstract: Reconstructing and understanding historical lake levels provides information about how climate influences lake level fluctuations, which is important for managing Lake Michigan- Huron’s (MH) coasts. This study reconstructs historical MH lake levels using ten ring-width chronologies from Southeast Alaska, which are significantly correlated at the 0.01 confidence level with January – June average MH lake levels. Tree ring chronologies from Southeast Alaska can be used to create a model of MH because of atmospheric teleconnections, like the Pacific North American Pattern (PNA), which produce similar atmospheric pressure anomalies across both regions. The model explains 33.8% of the variance in MH lake levels (January – June), and the validity of the model was tested through a series of calibration and verification statistics, confirming a well-verified stable relationship through time.
Findings indicate that MH lake level fluctuations are primarily based on large-scale atmospheric climate patterns that may be altered by human activity, volcanic eruptions, or strong climate events. Reconstructed high lake levels are attributed to volcanic activity in the 1690s, 1673, 1755, and 1809 and a strong El Niño event from 1876 to 1878, whereas lows are attributed to droughts, corresponding with the conditions of the 1930s Dust Bowl.

https://woostergeologists.scotblogs.wooster.edu

Learning about environmental change from tree rings