Lamont Weekly Report, April 19, 2019

    This was a week that will be remembered primarily for events unrelated to Earth science, from the horrific fire Monday night at the Notre Dame cathedral to yesterday’s release of the Mueller report. The Earth nonetheless featured in a New York Times story Wednesday on the views of all 18 declared Democratic candidates for President on how best to address climate change (

    I spent the first two workdays this week at Stanford University, to chair a visiting committee to their Department of Geophysics, one of four departments in the university’s School of Earth, Energy & Environmental Sciences. Service on such committees gives me an opportunity to see how another university addresses some of the issues we face at Lamont. A fringe benefit for this assignment was the opportunity to catch up with former Lamont Postdoctoral Research Scientist Lucia Gualtieri, who will be joining the Stanford Geophysics faculty in August, and former Lamont graduate student Winnie Chu, who is now at Stanford as a Postdoctoral Research Fellow in Geophysics and has accepted an offer of a faculty position at Georgia Tech.

    On Monday, the Proceedings of the National Academy of Sciences published a paper by Shilei Li, Maureen Raymo, and their coauthors on the relation between the stable isotopes of potassium in river water and the intensity of chemical weathering of the rocks in the river’s drainage basin. From measurements of the potassium isotopes in dissolved load and sediments from major rivers and their tributaries in China, the group showed that 41K is preferentially partitioned into aqueous solutions relative to 39K, and that the excess 41K correlates negatively with the silicate weathering intensity of the drainage basin. Global models that incorporate K isotope mass balance calculations point to a sensitivity of excess heavy potassium in seawater to changes in continental weathering intensity, an important component of the global carbon cycle, implying that potassium isotopes in ancient seawater can serve as a proxy for continental weathering intensity through Earth history. A Marie Aronsohn story on the paper’s findings was posted Monday (

    On Wednesday, Science Advances published a paper led by Jordan Abell on the use of measurements of soluble salts at an Early Neolithic archeological site in Turkey to document millennial-scale evolution in the domestication and management of sheep and goats. Jordan and his colleagues interpreted the salt concentrations as signatures of a mix of animal and human urine. With a mass balance model they showed that the salt concentrations at the site point to only slow increases in the human and animal population between 10,400 and 10,000 years ago but an abrupt increase in the combined population from about 10,000 to 9700 years ago, supportive of a rapid shift to animal domestication. A Sarah Fecht story on the paper’s findings was posted Wednesday (, and the results were widely covered in the media, including articles in The Atlantic ( and History Channel (

   April is Earth Month (, and a Phebe Pierson web story posted on Wednesday summarized a scientific question-and-answer program that the Earth Institute is offering on Instagram this month ( The breadth of questions received to date was illustrated by three questions answered by Jason Smerdon, Dorothy Peteet, and Pierre Dutrieux.

    Yesterday, Kuheli Dutt gave the invited keynote talk at the Women of Geoscience Symposium held at Yale University’s Department of Geology and Geophysics ( Kuheli’s presentation was on the topic of “Diversity, inclusion, and identity in the geosciences: Where do we go from here?”

    The R/V Marcus Langseth will sail from Honolulu later today or tomorrow to complete the second part of the Hawaiian-Emperor Seamount Chain Seismic Experiment, co-led by Donna Shillington and Tony Watts ( On this cruise, the shop will conduct seismic imaging across and along a portion of the Emperor Seamount chain in the northern Pacific.

    Marie Aronsohn’s interview of Maureen Raymo, which appeared in Lamont’s 2018 Annual Report and touched on Mo’s research and the work of the Lamont Core Repository, was reprised on our web site on Tuesday ( Also on Tuesday, as part of AGU’s Centennial Collection of Third Pod from the Sun podcasts, Eos reposted an interview with the University of Arizona’s Jessica Tierney on her paleoclimate work with Peter de Menocal on the “Green Sahara” era 5000 to 11,000 years ago and its possible role in the migration of human populations in the region ( Yesterday, Jen Lamp’s final blog from her fieldwork in the McMurdo Dry Valleys this past austral summer was posted on our web site, and it offers a fascinating glimpse into the detailed considerations needed to set up and operate yearlong experiments in Antarctica ( Also yesterday, Marco Tedesco was quoted multiple times in a Washington Post story on the anomalously warm temperatures in Greenland this year and the unusually early onset of the summer melting season ( 

    This afternoon’s Earth Science Colloquium speaker will be Eugene Humphreys, Professor of Geophysics at the University of Oregon ( and an expert on the tectonics, geodynamics, and seismic characteristics of the western U.S. Gene’s seminar will be on “Laramide-age growth of the Wyoming craton by oceanic plateau under-accretion.” May you grow your knowledge by joining me in accreting to his audience.