the scipp lab (Petersen group)
Stable & Clumped Isotopes for Paleoclimate and Paleoceanography
SCIPP Lab members Jade Zhang, Lucas Gomes, and Alex Quizon set out on a week of field work with UM Alum and SCIPP group collaborator Dr. Ian Winkelstern and two of his students from Grand Valley State University. The group is hoping to collect Pleistocene and Pliocene marine mollusks from the US East Coast. Good luck!
Jade’s first paper is now published in the journal Paleooceanography and Paleoclimatology. Congrats Jade! In this work, Jade analyzed fossil shells of the species Cittarium pica, a large gastropod known as the Indian Top Shell. She sampled these shells along their spiral growth direction to reconstruct ocean temperatures and oxygen isotopic compositions (seawater d18O) throughout a few years of their lifetime. These shells date from the Last Interglacial (LIG) interval (~125,000 years ago), a period when global climate was 1-2 degrees warmer and sea levels were 6-9m higher. Despite overall global warmth, we found Bermuda was actually slightly cooler during the LIG, consistent with other records from the region. We also found unexpectedly high variability in d18Oseawater, which we linked to freshwater discharge from an underground aquifer into the near coastal areas.
LINK TO PAPER: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2020PA004145
Sierra and Jade spent ~ a week in Bermuda in early May collecting fossil shells and water samples towards Jade’s PhD research, recently funded by NSF! We were joined by Ian Winkelstern, a UM alum and colleague. We visited >10 locations, many undescribed and undated in the literature and brought home ~45 lbs of fossils and rocks (with only a minor customs snafu involving an apple). These fossils will be analyzed for their clumped and stable isotopic composition at bulk and subannual timescales to reconstruct Bermudan mean climate and seasonality during the last interglacial period (and possibly during older interglacials as well, pending dating of some outcrops)!
The highlight of the trip was our last day of field work, which we did via kayak. We visited uninhabited small islands in the Great Bay of Bermuda and found so many fossil bivalves!! We were very excited! It’s amazing that this counts as work!
Jade is already asking when we can go back.
We are excited to announce that Sierra was selected as a recipient of the UM Crosby Research Award this year! The money from this award will go towards supporting planned field work in Bermuda in April/May, where Sierra and Jade (with collaborator Ian Winkelstern) will be collecting fossil shells from previous interglacial intervals.
Here at UM, we are lucky to be at an institution with a commitment to supporting their female and junior faculty, and the Crosby Award is a perfect example of the type of program that makes life just a little bit easier for a young female PI. Thank you ADVANCE program for this award!
Our collaborator Ian Winkelstern just published a paper on our work reconstructing Bermudan Climate.
We found that, in Bermuda, interglacial climate during MIS 5e was slightly cooler than modern. This is in line with CLIMAP reconstructions of the North Atlantic region. At a second MIS 5e outcrop a few km away from the first, we also found evidence for meltwater (10C cooler temps, 2 permil lower d18Owater), which was very surprising, given the mid-ocean location of Bermuda. Based on the age, we attribute this meltwater to melting Greenland.
Surprising and exciting results!!