A5082516828- Geology and Paleoclimatology Research
- Methane Hydrates and Related Phenomena
- Geological formations and processes
- Geological and Geochemical Analysis
- Cryospheric studies and observations
- Geochemistry and Elemental Analysis
- Paleontology and Stratigraphy of Fossils
- Astro and Planetary Science
- Isotope Analysis in Ecology
- Polar Research and Ecology
- earthquake and tectonic studies
- Pleistocene-Era Hominins and Archaeology
- Geomagnetism and Paleomagnetism Studies
- Geochemistry and Geologic Mapping
- Hydrocarbon exploration and reservoir analysis
- Planetary Science and Exploration
- Spacecraft and Cryogenic Technologies
- Geological and Geophysical Studies
- Geophysics and Gravity Measurements
- Geological Studies and Exploration
- Astronomical Observations and Instrumentation
- Offshore Engineering and Technologies
- Marine and environmental studies
- Groundwater and Isotope Geochemistry
- Evolution and Paleontology Studies
Lamont-Doherty Earth Observatory
2016-2025
Columbia University
2016-2025
Earth Island Institute
2024
University of Tasmania
2020
International Ocean Discovery Program
2017
University of Bristol
2015
Barnard College
2012
University of Maryland, College Park
2007
Stony Brook University
1992-1995
State University of New York
1993
Millennial climate oscillations of the glacial interval are interrupted by extreme events, so‐called Heinrich events North Atlantic. Their near‐global footprint is a testament to coherent interactions among Earth's atmosphere, oceans, and cryosphere on millennial timescales. detritus appears have been derived from region around Hudson Strait. It was deposited over approximately 500 ± 250 years. Several mechanisms proposed for origin layers: binge‐purge cycle Laurentide ice sheet, jökulhlaup...
Research Article| April 01, 2000 Climate change and the collapse of Akkadian empire: Evidence from deep sea H. M. Cullen; Cullen 1Lamont-Doherty Earth Observatory Columbia University, Palisades, New York 10964, USA Search for other works by this author on: GSW Google Scholar P. B. deMenocal; deMenocal S. Hemming; Hemming G. F. Brown; Brown 2University Utah, Park City, Utah 84112, T. Guilderson; Guilderson 3Lawrence Livermore National Laboratory, Livermore, California 94551, Sirocko 4Institut...
A major obstacle in understanding the evolution of Cenozoic climate has been lack well dated terrestrial evidence from high-latitude, glaciated regions. Here, we report discovery exceptionally preserved fossils lacustrine and organisms McMurdo Dry Valleys sector Transantarctic Mountains for which have established a precise radiometric chronology. The fossils, include diatoms, palynomorphs, mosses, ostracodes, insects, represent last vestige tundra community that inhabited mountains before...
Abstract The 40Ar/39Ar dating method is among the most versatile of geochronometers, having potential to date a broad variety K-bearing materials spanning from time Earth’s formation into historical realm. Measurements using modern noble-gas mass spectrometers are now producing dates with analytical uncertainties ∼0.1%, thereby providing precise constraints for wide range geologic and extraterrestrial processes. Analyses increasingly smaller subsamples have revealed age dispersion in many...
Evidence from high-sedimentation-rate South Atlantic deep-sea cores indicates that global and Southern Ocean carbon budget shifts preceded thermohaline circulation changes during the last ice age initiation termination these were by ice-sheet growth retreat, respectively. No consistent lead-lag relationships are observed abrupt millennial warming events age, allowing for possibility ocean triggered some millenial climate changes. At major glacial-interglacial transitions, responded...
We present a glacial record from the western Olympus Range, East Antarctica, that documents permanent shift in thermal regime of local glaciers, wet- to coldbased regimes, more than 13.94 m.y. ago. This provides fi rst terrestrial evidence linking middle Miocene global climate cooling reorganization Antarctic cryosphere and subsequent growth polar Ice Sheet. The composite stratigraphic constructed eld mapping analyses 281 soil excavations shows classic wetbased till (Circe till, including an...
One of the key activities during initial phase international GEOTRACES program was an extensive intercalibration effort, to ensure that results for a range trace elements and isotopes (TEIs) from different cruises laboratories can be compared in meaningful way. Here we present efforts on neodymium rare earth seawater marine particles. Fifteen reported dissolved 143 Nd/ 144 Nd ratios at three locations (BATS 15 m, BATS 2000 SAFe 3000 m), with overall agreement within 47 57 ppm (2σ standard...
Abstract Antarctica is one of the most vulnerable regions to climate change on Earth and studying past present responses this polar marine ecosystem environmental a matter urgency. Sedimentary ancient DNA ( sed aDNA) analysis can provide such insights into ecosystem-wide changes. Here we authenticated (through extensive contamination control aDNA damage analysis) metagenomic eukaryote from Scotia Sea region acquired during IODP Expedition 382. We also record ~1 Mio. years diatom chlorophyte...
Prior to ~1 million years ago (Ma), variations in global ice volume were dominated by changes obliquity; however, the role of precession remains unresolved. Using a record North Atlantic rafting spanning past 1.7 years, we find that onset within given glacial cycle (reflecting sheet expansion) consistently occurred during times decreasing obliquity whereas mass wasting (ablation) events tied minima precession. Furthermore, our results suggest ubiquitous association between precession-driven...
Past interglacial climates with smaller ice sheets offer analogs for sheet response to future warming and contributions sea level rise; however, well-dated geologic records from formerly ice-free areas are rare. Here we report that subglacial sediment the Camp Century core preserves direct evidence northwestern Greenland was free during Marine Isotope Stage (MIS) 11 interglacial. Luminescence dating shows just beneath deposited by flowing water in an environment 416 ± 38 thousand years ago....