This glacial erratic made is way down to Wayne County during the course of the 20 glacial cycle over the past 2 million years. Before that is was buried and exhumed in the earth’s crust to a depth of over 10 km at least twice. A complex history that not all the students were comfortable with…

 

 

 

The diagram above came up in the Emily and Sarah’s presentation. This is for recent climate change relevant to the warming world of today. What might this look like for glacial times, for longer timecales? for millennial-scale variations? What is missing and what may not apply for the deglacial times we need to consider in the lake core study? How about the tree-ring study? Identifying which forcings are relevant needs to be considered.

One of the big questions that remains with the Mastodon site is how does the marl in our cores link to the excavation. Clint Walker had a good suggestion to dig a ditch 2 meters down through the bog. Now we have a better idea. We will examine the results of this excavation (many thanks to Dale Baker, backhoe operator).

 

A blog that you should really subscribe to and check in on occasionally is RealClimate.
This week’s entry is concerned with – How do Trees Change the Climate? This question will become more important to us as we continue the Ohio tree-ring work – how did the climate change when Ohio was deforested ~200 years ago? or did it change? how would we know and how could we attribute the change to one factor or another? Attribution of climate change is fundamental and it is not always straightforward.

 

We spent a beautiful Fall morning at the Cedar Creek Mastodon site with Dr. Wilson, Dr. Brush (U. Ashland), Dr. Kardulias and other experts examining the sediments and mastodon remains. See Dr. Wilson’s post for some excellent photos and suggestions regarding the sediments at the site.

 

Above is the reconstructed temperatures from the Greenland Ice Core. Now that we have radiocarbon ages from our sediment core we can put it into the larger context of the Northern Hemisphere temperature history. The x-axis is in calibrated yrBP – where does the marl fall on this diagram?

We just received the second date from Beta Analytic for the Cedar Creek Mastodon site. This was sampled by Kelsey and Haley and included seeds and a bit of carbon from the lower portion of the peat – this is the Second_date. The First_date I handed out in class.

We have a quiz Wednesday on the principles of tree rings and the significance of the C14 ages – be sure to go over the preparation questions.