Guest Blogger: Lynnsey Delio, The Keck Geology 2025 team has been working in the Wooster dendrochronology lab for the first week of research. The team cored the oak tree in front of Scovel on day 1 for some practice coring. They also made use of the woodshop in Scovel Hall and practiced sanding and mounting cores. 
 

Dexter, Lynnsey, Lev, and Landon coring the oak tree in front of Scovel Hall. 
 

Lev with a core reveal!
 
The team has also been working with programs COFECHA and CooRecorder in the computer lab to mark the tree rings on red cedars from Southeast Alaska. They have been working to create an optimized red cedar tree ring series for the area, dating back centuries. This data can be used to compare to other tree ring series and look for climate signals and responses. These climate responses can be analyzed from a global climate perspective to understand the correlation between dendrochronology and global climate phenomena.  
To accurately date the cedar cores, the team used cores from previously dated red cedars in Southeast Alaska to correlate them to the undated samples. Some of these previously dated cores included logged trees that were intended for use in totem poles. 
 

The team

https://woostergeologists.scotblogs.wooster.edu

The lead author of this work, Fred (Wenshuo) Zhao, photographed in front of the Mendenhall Glacier in Juneau, Alaska. The logs at his feet, recently exposed by the retreating ice, are the subject of his undergraduate thesis and this publication. The College of Wooster Tree Ring Lab has an extensive collection of subfossil wood (trees run over in the past by glaciers) and this wood is often stained by exposure to the elements altering the color of the wood. This alteration inhibits the measurement of tree-ring parameters like blue intensity measurements. Measuring blue intensity (BI) has been shown to improve climate reconstruction and improve general tree-ring dating (Wilson et al, 2017, 2019). Fred, with the great help of Junpeng Fu and Nick Wiesenberg at Wooster, chemically treated the wood showing an improved climate signal in the BI measurements after treatment.  This paper describes the process and evaluation of this chemical method using wood sampled from along the Gulf of Alaska as an example.

Degrees C
One of the clever tests that Fred performed to evaluate the improved climate signal was to compare climate signal of latewood blue intensity measurements before soaking in hydrogen peroxide (graph on the left) and after soaking (right)

https://woostergeologists.scotblogs.wooster.edu

Guest Bloggers: Mihalis Protopapadakis and Amanda Flory

This year the College of Wooster Tree Ring Lab flew to Ketchikan for our 2024 Alaska trip. July 6th and 7th were spent in Ketchikan, where we collected samples from Deer Mountain after a rigorous hike. On July 8th we took a ferry to Prince of Wales Island, where we collaborated with Alaska Youth Stewards in the city of Klawock to create a new tree-ring record of the region. While in Klawock, we had the opportunity to bond with the AYS team and explore the local Tlingit culture.

The city of Ketchikan on a rare sunny day.

The Wooster team in front of a Tlingit totem pole.

The view from halfway up Deer Mountain.

Dr. Wiles riding the saddleback of two cedars.

The Wooster team hard at work.

Sun-rays peeking through remnants of possible staurolite crystals in the phyllite bedrock.

The Deer Mountain tree-ring data up to 1998. The chronology highlights the volcanic eruptions of the 1690s and 1809, extending the tail-end of the Little Ice Age. The team collected samples to update the record with the last 25 years.

Kite surfer catching the waves of the ferry to Prince of Wales island.

Meeting the AYS team and other collaborators in Klawock.

The team

https://woostergeologists.scotblogs.wooster.edu

Guest Bloggers: Lilly Hinkley and Tyrell Cooper
Tyrell, Lilly, Nick and Dr. Wiles of Wooster’s Tree Ring Lab (WTRL) were in Juneau and Hoonah, Alaska working in collaboration with the Alaskan Youth Stewards (AYS) in order to extend our tree ring chronologies. Once we collect the tree cores, the WTRL group will head back to The College of Wooster to prep and measure the cores and do a climatic analysis on them to try and connect the data with some of the Tlingit oral histories we learned about during our time. 

Nick, Tyrell and Lilly at the Mendenhall Glacier ice margin.
Day 1
Tyrell and Lilly safely landed in Juneau. We fueled up and then went on a short walk around Mendenhall Glacier Lake where we saw a triple sun dog – a sign of good luck as we embarked on our journey in Alaska.
We met up with a fellow dendrochronologist, Markus Stoffel (left), along with his family who are from Switzerland. We also met up with another colleague, Ben Gaglioti (second from left) who works as a researcher at University of Alaska Fairbanks. Ben joined us while we were in Hoonah as well.
 
Lilly and Tyrell in front of Nugget Falls. Which pours from

https://woostergeologists.scotblogs.wooster.edu