A5066178961- Geology and Paleoclimatology Research
- Atmospheric and Environmental Gas Dynamics
- Cryospheric studies and observations
- Methane Hydrates and Related Phenomena
- Isotope Analysis in Ecology
- Polar Research and Ecology
- Winter Sports Injuries and Performance
- Hydrocarbon exploration and reservoir analysis
- Climate change and permafrost
- Peatlands and Wetlands Ecology
- Groundwater and Isotope Geochemistry
- Geological formations and processes
- Coastal wetland ecosystem dynamics
- Arctic and Antarctic ice dynamics
- Landslides and related hazards
- Pleistocene-Era Hominins and Archaeology
- Tree-ring climate responses
- Medieval Architecture and Archaeology
- Archaeological and Geological Studies
- Archaeology and ancient environmental studies
- Nuclear Physics and Applications
- Archaeological and Historical Studies
- Paleontology and Stratigraphy of Fossils
- Fire effects on ecosystems
- Karst Systems and Hydrogeology
British Antarctic Survey
2019-2025
University of Cambridge
2016-2020
Oregon State University
2014-2020
Northumbria University
2019
An understanding of the mechanisms that control CO2 change during glacial-interglacial cycles remains elusive. Here we help to constrain changing sources with a high-precision, high-resolution deglacial record stable isotopic composition carbon in CO2(δ(13)C-CO2) air extracted from ice samples Taylor Glacier, Antarctica. During initial rise atmospheric 17.6 15.5 ka, these data demarcate decrease δ(13)C-CO2, likely due weakened oceanic biological pump. From 11.5 continued 40 ppm is associated...
Falling from a fall in rainfall How much did have to decrease trigger the collapse of Lowland Classic Maya civilization during Terminal Period? This is well-cited example how past climate change—in this case, drought—can disrupt population. Evans et al. measured isotopic composition water Lake Chichancanab, Mexico, quantify precipitation decreased that period. Annual must fallen by around 50% on average and up 70% peak drought conditions. Science , issue p. 498
Permafrost and methane hydrates are large, climate-sensitive old carbon reservoirs that have the potential to emit large quantities of methane, a potent greenhouse gas, as Earth continues warm. We present ice core isotopic measurements (Δ14C, δ13C, δD) from last deglaciation, which is partial analog for modern warming. Our results show emissions in response deglacial warming were small (<19 teragrams per year, 95% confidence interval) argue against similar future also indicate biomass...
Ice core records of carbon dioxide (CO
Abstract Changes in atmospheric CO 2 on millennial‐to‐centennial timescales are key components of past climate variability during the last glacial and deglacial periods (70–10 ka), yet sources mechanisms responsible for fluctuations remain largely obscure. Here we report 13 C/ 12 C ratio a interval period at submillennial resolution, with coeval histories , CH 4 N O concentrations. The carbon isotope data suggest that millennial‐scale Marine Isotope Stage 3 is driven by changes organic...
Abstract Noble gases in ice cores enable reconstructions of past mean ocean temperature. A recent result from the clathrate‐containing WAIS Divide Ice Core showed tight covariation between and Antarctic temperatures throughout last deglaciation, except for Younger Dryas interval. In beginning this interval, oceans warmed at 2.5 °C/kyr—three times greater than estimates modern warming. If valid, challenges our understanding mechanisms controlling heat uptake. Here we reconstruct temperature...
Abstract. New ice cores retrieved from the Taylor Glacier (Antarctica) blue area contain and air spanning Marine Isotope Stage (MIS) 5–4 transition, a period of global cooling sheet expansion. We determine chronologies for bubbles in new by visually matching variations gas- ice-phase tracers to preexisting core records. The reveal an age–gas age difference (Δage) approaching 10 ka during MIS 4, implying very low snow accumulation zone. A revised chronology analogous section Dome (84 55 ka),...
Abstract The extent of grounded ice and buttressing by the Ronne Ice Shelf, which provides resistance to outflow streams, moderate West Antarctic Sheet stability. During Last Glacial Maximum, sheet advanced was near Weddell Sea continental shelf break. timing subsequent retreat relative roles grounding line changes remain unresolved. Here we use an core record from at Skytrain Rise constrain speed early Holocene retreat. Measured δ 18 O total air content suggest that surface elevation...
Recent work demonstrates that the Skytrain ice core, retrieved from Weddell Sea Embayment in West Antarctica, can inform us about (in-)stability of Ronne-Filcher Ice Shelf and Antarctic Sheet past warm periods. Here we switch our focus to Last Glacial period at describe &#8220;Calcium Conundrum&#8221;, which may be linked sheet dynamics.&#160;The calcium record diverges those other cores across several distinct time intervals. The increased Ca is not accompanied by a...
The West Antarctic Ice Sheet (WAIS), holding close to five metres sea level equivalent of ice, has long been considered one the major tipping elements in Earth&#8217;s climate system. A recent study suggests that WAIS is perhaps most decisive this system as well (Wang et al., 2023). Total Air Content (TAC) data (a proxy for ice sheet elevation) from Skytrain Rise core (~79&#176;S, 078&#176;W, 784 m altitude) shows rapid elevation changes around 100 within decadal timescales 8,000...
Abstract Carbonate cave deposits (speleothems) have been used widely for paleoclimate reconstructions; however, few studies examined the utility of other speleothem-forming minerals this purpose. Here we demonstrate first time that stable isotopes (δ 17 O, δ 18 O and δD) structurally-bound gypsum (CaSO 4 ·2H 2 O) hydration water (GHW) can be to infer paleoclimate. Specifically, a 63 cm-long stalactite from Sima Blanca Cave reconstruct climate history SE Spain ~ 800 BCE CE. The indicates wet...
Abstract. Old ice for paleo-environmental studies, traditionally accessed through deep core drilling on domes and ridges the large sheets, can also be retrieved at surface from sheet margins blue areas. The practically unlimited amount of available these sites satisfies a need in community studies trace components requiring sample volumes. For margin to useful as ancient archives, stratigraphy needs understood age models established. We present measurements trapped gases Taylor Glacier,...