A5013748606- Geology and Paleoclimatology Research
- Isotope Analysis in Ecology
- Methane Hydrates and Related Phenomena
- Geological and Geochemical Analysis
- Paleontology and Stratigraphy of Fossils
- earthquake and tectonic studies
- Geochemistry and Elemental Analysis
- Geological formations and processes
- Marine and coastal ecosystems
- Geochemistry and Geologic Mapping
- Geological and Geophysical Studies
- Groundwater and Isotope Geochemistry
- Radioactive contamination and transfer
- Heavy metals in environment
- Radioactive element chemistry and processing
- Hydrocarbon exploration and reservoir analysis
- Pacific and Southeast Asian Studies
- Marine and environmental studies
- Atmospheric and Environmental Gas Dynamics
- Radioactivity and Radon Measurements
- Geological Studies and Exploration
- Water Quality and Resources Studies
- Oceanographic and Atmospheric Processes
- Toxic Organic Pollutants Impact
- Geological and Tectonic Studies in Latin America
Texas A&M University
2016-2025
Mitchell Institute
2017-2024
Brown University
2024
Laboratoire des Sciences du Climat et de l'Environnement
2024
Tulane University
1996-2007
Yale University
1997-1999
Columbia University
1990-1997
Lamont-Doherty Earth Observatory
1990-1997
McMaster University
1988-1990
Carleton University
1986
New ReOs isotopic results for Os-poor basalts from St. Helena, the Comores, Samoa, Pitcairn and Kerguelen dramatically expand known range of initial 186Os/187Os ratios in OIBs to values as high 1.7. In contrast Os uniformity Os-rich HIMU islands Tubuai Mangaia found by Hauri Hart [1], our Helena span most variability oceanic (initial 187Os/186Os ranges 1.2 1.7). Generation such radiogenic mantle requires melting source materials that contain large proportions recycled crust. The very low...
Biological productivity in the equatorial Pacific is relatively high compared with other low-latitude regimes, especially east of dateline, where divergence driven by trade winds brings nutrient-rich waters Equatorial Undercurrent to surface. The one three principal high-nutrient low-chlorophyll ocean regimes biological utilization nitrate and phosphate limited, part, availability iron. Throughout most Pacific, upwelling water from supplies far more dissolved iron than delivered dust, as...
Abstract 230 Th normalization is a valuable paleoceanographic tool for reconstructing high‐resolution sediment fluxes during the late Pleistocene (last ~500,000 years). As its application has expanded to ever more diverse marine environments, nuances of systematics, with regard particle type, size, lateral advective/diffusive redistribution, and other processes, have emerged. We synthesized over 1000 sedimentary records from across global ocean at two time slices, Holocene (0–5,000 years...
Sub-aerial lavas from the single ocean island of La Palma, Canary Islands show as large a variation in 187Os186Os isotope ratios (1.13–1.59) found across all French Polynesia [1]. The Palma lavas, however, display restricted range chemical composition and have been erupted within last 3.5 Ma. highest Os isotopic compositions are observed with low concentrations. An uplifted sequence that represent early phase submarine growth island, extremely heterogeneous ratios, 1.21 to 3.53, most...
At four sites in the central equatorial Pacific Ocean flux of extraterrestrial ³He, determined using excess 230 Th profiling method, is 8 × 10 −13 cm³ STP cm −2 ka −1 . This supply rate constant to within 30%. these same sites, however, burial chronostratigraphic accumulation rates, varies by more than a factor 3. The lowest which occur north equator at 1°N, 139°W are lower global average ³He 20% and indicate that sediment winnowing may have occurred. highest recorded 2°S, higher 100%,...
We present a detailed down-core analysis of helium isotope ratios and concentrations for bulk sediments from the central Equatorial Pacific that span last two glacial-interglacial cycles. Measured 3He4He range 1.0 × 10−5 to 2.1 10−4, or 7.4 149 times atmospheric ratio. The 3He interplanetary dust particles (IDPs) constitutes virtually all measured within sediment. Because carbonate accumulation rates are high in Pacific, lower than have been elsewhere, 4.7 10−13 3.0 10−12 cm3STP · g−1. If...
Abstract The dynamics shaping the El Niño‐Southern Oscillation's (ENSO) response to present and future climate change remain unclear, partly due limited paleo‐ENSO records spanning past abrupt events. Here, we measure Mg/Ca ratios on individual foraminifera reconstruct east Pacific subsurface temperature variability, a proxy for ENSO across last 25,000 years, including millennial‐scale events of deglaciation. Combining these data with system model output reveals divergent responses Northern...
Understanding intermediate water circulation across the last deglacial is critical in assessing role of oceanic heat transport associated with Atlantic Meridional Overturning Circulation variability abrupt climate events. However, links between and events such as Younger Dryas (YD) Heinrich Event 1 (H1) are still poorly constrained. Here, we reconstruct changes Antarctic Intermediate Water (AAIW) subtropical North over past 25 kyr by measuring authigenic neodymium isotope ratios sediments...
Previous studies showed that sea surface salinity (SSS) in the Florida Straits as well Current transport covaried with changes North Atlantic climate over past two millennia. However, little is known about earlier Holocene hydrographic variability Straits. Here, we combine Mg/Ca‐paleothermometry and stable oxygen isotope measurements on planktonic foraminifera Globigerinoides ruber (white variety) from sediment core KNR166–2 JPC 51 (24° 24.70′ N, 83° 13.14′ W, 198 m deep) to reconstruct a...
Research Article| September 07, 2018 Iron fertilization of primary productivity by volcanic ash in the Late Cretaceous (Cenomanian) Western Interior Seaway Zhirui Zeng; Zeng 1Department Geology and Geophysics, Texas A&M University, College Station, Texas, 77843, USA Search for other works this author on: GSW Google Scholar Madison Pike; Pike Michael M. Tice; Tice * *E-mail: mtice@geos.tamu.edu Caitlyn Kelly; Kelly Franco Marcantonio; Marcantonio Guangjian Xu; Xu Ivan Maulana Author Article...