A5067482481- Geology and Paleoclimatology Research
- Isotope Analysis in Ecology
- Methane Hydrates and Related Phenomena
- Atmospheric and Environmental Gas Dynamics
- Marine and coastal ecosystems
- Geological formations and processes
- Oceanographic and Atmospheric Processes
- Marine Biology and Ecology Research
- Paleontology and Stratigraphy of Fossils
- Archaeology and ancient environmental studies
- Pleistocene-Era Hominins and Archaeology
- Climate variability and models
- Groundwater and Isotope Geochemistry
- Ocean Acidification Effects and Responses
- Radioactive contamination and transfer
- Cryospheric studies and observations
- Geological and Geophysical Studies
- Geological and Geochemical Analysis
- Hydrocarbon exploration and reservoir analysis
- Arctic and Antarctic ice dynamics
- Marine and environmental studies
- CO2 Sequestration and Geologic Interactions
- Radioactivity and Radon Measurements
- Geochemistry and Elemental Analysis
- Coral and Marine Ecosystems Studies
Lamont-Doherty Earth Observatory
2011-2022
Columbia University
2010-2022
Arizona State University
2016
In-Q-Tel
2013
American Geophysical Union
2013
ETH Zurich
2004
University of Southern California
2004
NOAA Atlantic Oceanographic and Meteorological Laboratories
1999
National Oceanic and Atmospheric Administration
1999
Woods Hole Oceanographic Institution
1995-1999
Hughen et al. [1998] have documented that during the first 200 years of Younger Dryas time 14 C content atmospheric CO 2 increased by ∼50‰ and remainder this 1200‐year‐duration cold event it steadily declined. The initial increase in C/C was likely result a reduction Atlantic's conveyor circulation. However, were subsequent radiocarbon decline due to rejuvenation potent heat pump, then is difficult understand why climate conditions northern Atlantic basin remained throughout Dryas. Modeling...
Gas exchange rate studies carried out in the laboratory suggest that stagnant film model is adequate to relate transfer coefficients of most gases between atmosphere and sea an accuracy ±15%. Estimates average thickness prevailing for world ocean based on distribution natural radiocarbon, bomb-produced radon are good agreement. Radon data from BOMEX area station PAPA lend support Kanwisher's suggestion gas rates should vary proportion square wind velocity. These observations permit a number...
During the last glacial period, Earth's climate underwent frequent large and abrupt global changes. This behavior appears to reflect ability of ocean's thermohaline circulation assume more than one mode operation. The record in ancient sedimentary rocks suggests that similar changes plagued Earth at other times. trigger mechanism for these reorganizations may have been antiphasing polar insolation associated with orbital cycles. Were ongoing increase atmospheric CO2 levels another such...
230Th-dated oxygen isotope records of stalagmites from Sanbao Cave, China, characterize Asian Monsoon (AM) precipitation through the ends third- and fourthmost recent ice ages. As a result, AM for past four glacial terminations can now be precisely correlated with those cores marine sediments, establishing timing sequence major events. In all cases, observations are consistent classic Northern Hemisphere summer insolation intensity trigger an initial retreat northern sheets. Meltwater...
A detailed curve of ice volume versus time is needed in order to test the validity hypothesis that changes earth's orbital parameters are cause oscillations Pleistocene climate. Although absolute ages available for glacial moraines and raised coral reefs provide a number key points, they by no means allow continuous be drawn. Those points exist, however, entirely consistent with O 18 /O 16 curves from deep‐sea cores good approximations record. If so, then primary cycle must sawtoothed...
Carbon capture and storage (CCS) provides a solution toward decarbonization of the global economy. The success this depends on ability to safely permanently store CO2 This study demonstrates for first time permanent disposal as environmentally benign carbonate minerals in basaltic rocks. We find that over 95% injected into CarbFix site Iceland was mineralized less than 2 years. result contrasts with common view immobilization within geologic reservoirs takes several hundreds thousands Our...
The composition of the organic matter oxidized within thermocline Atlantic and Indian oceans has been estimated from chemical data along σ θ 27.0 27.2 horizons. These estimates are based on differences between preformed observed concentrations PO 4 , NO 3 total inorganic CO 2 alkalinity, O . Since these isopycnal horizons ventilated both north south, concentration take into account relative contributions two end‐members. proportions end‐members basis potential temperature water, assuming...
Emerged coral reef terraces on the Huon Peninsula in New Guinea were reported a reconnaissance dating study by Veeh and Chappell 1970. Age definition achieved was not good for several important terraces, we report here series of new 230 Th/ 234 U dates, which further clarify history late Quaternary eustatic sea level fluctuations. More than 20 complexes are present, ranging well beyond 250,000 yr old: concerned with seven lowest complexes. Major reef-building episodes dated 30 complex I at...
A 30,000-year paleotemperature record derived from noble gases dissolved in carbon-14-dated ground water indicates that the climate lowland Brazil (Piaui Province, 7 degrees S, 41.5 W; altitude, 400 meters) was 5.4 +/- 0.6 C cooler during last glacial maximum than today. This result suggests a rather uniform cooling of Americas between 40 S and N. tropical South America is consistent with pollen records, snow line reconstructions, strontium/calcium ratios delta(18)O coral records but...
The fate of fossil fuel carbon dioxide released into the atmosphere depends on exchange rates between and three major reservoirs, namely, oceans, shallow-water sediments, terrestrial biosphere. Various assumptions models used to estimate global budget for last 20 years are reviewed evaluated. Several versions recent atmosphere-ocean appear give reliable mutually consistent estimates uptake by oceans. On other hand, there is no compelling evidence which establishes that biomass has decreased...
As shown by the work of Dansgaard and his colleagues, climate oscillations one or so millennia duration punctuate much glacial section Greenland ice cores. These are characterized 5°C air temperature changes, severalfold dust content changes 50 ppm CO 2 changes. Both change best explained in mode operation ocean. In this paper we provide evidence which suggests that surface water conditions similar present record from a deep sea core at 50°N. Based on finding, suggest driven salinity...
The island of Barbados, West Indies, was an area tectonic emergence during the Pleistocene. As Barbados uplifted, reef tracts formed around island. interaction gradual uplift and glacio-eustatic sea level fluctuations has resulted in formation a complex, terraced "coral cap." Each individual terrace represents elevated tract is therefore constructional rather than erosional origin. Subsequent to formation, terraces have been abraded by waves subjected minor faulting; particular, wave...
Barbados provides a possibly unique opportunity for reconstruction of the times and elevations late-Pleistocene high stands sea. The island appears to be rising from sea at uniform rate that is fast enough separate in elevation coral-reef tracts formed successive Unaltered coral found lower terraces enables high-precision Th 230 : U 234 Pa 231 235 dating. Three distinct are about 122,000, 103,000, 82,000 years ago. New dates deep-sea core also indicate Ericson's W-X cold-to-warm climatic...