A5016361639- Geology and Paleoclimatology Research
- Marine and environmental studies
- Karst Systems and Hydrogeology
- Archaeology and ancient environmental studies
- Groundwater and Isotope Geochemistry
- Pleistocene-Era Hominins and Archaeology
- Geological formations and processes
- Climate variability and models
- Tree-ring climate responses
- Peatlands and Wetlands Ecology
- Aeolian processes and effects
- Metallurgy and Cultural Artifacts
- Methane Hydrates and Related Phenomena
- Cryospheric studies and observations
- Coastal wetland ecosystem dynamics
- Ancient and Medieval Archaeology Studies
- Isotope Analysis in Ecology
- Pacific and Southeast Asian Studies
- Historical and Archaeological Studies
- Tropical and Extratropical Cyclones Research
- earthquake and tectonic studies
- Maritime and Coastal Archaeology
- Geological Formations and Processes Exploration
- Landslides and related hazards
- Groundwater flow and contamination studies
Northumbria University
2016-2025
Romanian Academy
2017-2022
University of Oxford
2010-2019
Emil Racovita Institute of Speleology
2017-2018
Oregon State University
2009-2010
Abstract Reproducible climate reconstructions of the Common Era (1 CE to present) are key placing industrial-era warming into context natural climatic variability. Here we present a community-sourced database temperature-sensitive proxy records from PAGES2k initiative. The gathers 692 648 locations, including all continental regions and major ocean basins. trees, ice, sediment, corals, speleothems, documentary evidence, other archives. They range in length 50 2000 years, with median 547...
Two speleothem stable isotope records from East-Central Europe demonstrate that Greenland Stadial 12 (GS12) and GS10-at 44.3-43.3 40.8-40.2 ka-were prominent intervals of cold arid conditions. GS12, GS11, GS10 are coeval with a regional pattern culturally (near-)sterile layers within Europe's diachronous archeologic transition Neanderthals to modern human Aurignacian. Sterile GS12 precede the Aurignacian throughout middle upper Danube region. In some northern Iberian Peninsula, such GS11...
Significance A speleothem geochemical record from northern Iran captures significant climate fluctuations during the mid-to-late Holocene at high resolution. Two abrupt shifts in Mg/Ca last for more than a century and are interpreted as enhanced dust activity, indicating threshold behavior response to aridity. Coincident gradual peaks δ 18 O support interpretation of regional drying. The precise chronology shows later event, 4.26 ka 3.97 ka, is coincident within decades period abandonment...
Abstract Between 5 and 4 thousand years ago, crippling megadroughts led to the disruption of ancient civilizations across parts Africa Asia, yet extent these climate extremes in mainland Southeast Asia (MSEA) has never been defined. This is despite archeological evidence showing a shift human settlement patterns region during this period. We report from stalagmite records indicating major decrease monsoon rainfall MSEA mid- late Holocene, coincident with African failure end Green Sahara....
The timing of the initial dispersal hominins into Eurasia is unclear. Current evidence indicates were present at Dmanisi, Georgia by 1.8 million years ago (Ma), but other ephemeral traces across predate Dmanisi. However, no hominin remains have been definitively described from Europe until ~1.4 Ma. Here we activity site Grăunceanu, Romania in form multiple cut-marked bones. Biostratigraphic and high-resolution U-Pb age estimates suggest Grăunceanu > 1.95 Ma, making this one best-dated early...
Abstract. Here we present a speleothem isotope record (POM2) from Ascunsă Cave (Romania) that provides new data on past climate changes in the Carpathian–Balkan region 8.2 ka until present. This paper describes an approach to constrain effect of temperature calcite δ18O values stalagmite POM2 over course middle Holocene (6–4 ka), and across 3.2 rapid change events. Independent pollen reconstructions are used this purpose. The combines temperature-dependent fractionation rain water during...
Significance A detailed record of historical lead (Pb) pollution from a peat bog in Serbia provides unique view on the extent and timing Balkan mining metallurgy. Evidence earliest European environmental is followed by large-scale sustained increases amount anthropogenically derived Pb after 600 BCE, through Roman/Byzantine periods, into medieval period. Occasional evidence drops output reflects disruptive socioeconomic impact periods turmoil. Our data show trend significantly different to...
Lead (Pb) isotopes provide valuable insights into the origin of Pb within a sample, typically allowing for reliable fingerprinting their source. This is useful variety applications, from tracing sources pollution-related Pb, to origins in archaeological artefacts. However, current approaches investigate source proportions via graphical means, or simple mixing models. As such, an approach, which quantitatively assesses and fingerprints signature analysed especially larger numbers sources,...
Abstract. Reconstructions of dust flux have been used to produce valuable global records changes in atmospheric circulation and aridity. These studies highlighted the importance marine terrestrial biogeochemistry nutrient cycling. By investigating a 10 800-year-long paleoclimate archive from Eastern Carpathians (Romania) we present first peat record changing deposition over Holocene for Carpathian–Balkan region. Using qualitative (X-ray fluorescence (XRF) core scanning) quantitative...
Abstract The interpretation of palaeoclimate archives based on oxygen isotopes depends critically a detailed understanding processes controlling the isotopic composition precipitation. In summer monsoonal realm, like Southeast Asia, seasonally and interannually depleted isotope ratios in precipitation have been linked to monsoon strength. However, some regions, such as central Vietnam, majority falls outside period. We investigate stable from Vietnam by combining moisture uptake calculations...
Abstract The winter and summer monsoons in Southeast Asia are important but highly variable sources of rainfall. Current understanding the monsoon is limited by conflicting proxy observations, resulting from decoupling regional atmospheric circulation patterns local rainfall dynamics. These signals difficult to decipher paleoclimate reconstructions. Here, we present a speleothem record covering Holocene find that changed synchronously, forced changes Pacific Indian Oceans. In contrast, shows...
The Romanian Carpathians are located at the confluence of three major atmospheric pressure fields: North Atlantic, Mediterranean and Siberian. Despite its importance for understanding past human impact climate change, high-resolution palaeoenvironmental reconstructions Holocene hydroclimate variability, in particular records extreme precipitation events area, rare. Here we present a 7500-year-long record climatic change recorded peatbog from Southern Carpathians, integrating palynological,...
Abstract. Reconstructing the spatio-temporal dynamics of glaciations and permafrost largely relies on surface deposits is therefore a challenge for every glacial period older than last due to erosion. Consequently, remain poorly constrained worldwide before ca. 30 ka. Since speleothems (carbonate cave deposits) form from drip water generally indicate absence an ice sheet permafrost, we evaluate how speleothem growth phases defined by U series dates align with past glacial–interglacial...
Subglacial environments are hotspots for chemical weathering with dynamic hydrological and microbial systems interacting freshly produced meltwater sediments. These processes can either drawdown or release atmospheric CO2 depending on the type extent of pathways. This study delves into in subglacial their broader implications global geochemical cycling.We employ meteoric 10Be, a cosmogenic nuclide, to assess neoformation silicate products as isotope be incorporated crystal structure clays,...
Speleothems are invaluable archives of past climate variability and offer important insights into monsoon dynamics across Southeast Asia. Different isotope systems have been employed to characterise autumn in this region, but multiple influencing factors render the interpretation proxy records ambiguous. To gain novel regional vegetation temperature changes, proxies required. Here, we combine traditional speleothem stable isotopes (δ¹⁸O...
Abstract The occurrence of heavy rainfall events is expected to undergo significant changes under increasing anthropogenic forcing. South-eastern Europe reacting rapidly such changes, therefore understanding and forecasting precipitation variability vital better comprehending environmental in this area. Here we present a sub-decadal reconstruction enhanced for the past 2000 years from Southern Carpathians, Romania using peat geochemistry. Five clear periods are identified at 125–250,...
We examine the relation between δ 18 O in rainwater collected southwestern Oregon and climate variables including temperature, parcel trajectory, precipitation amount, specific humidity. Local surface air temperature at time of sample collection explains a large proportion variability, suggesting that paleoclimatic archives are related to rainfall should be useful for qualitative reconstructions. Models Rayleigh distillation masses originating North Pacific can broadly constrain observed...
Abstract This paper reports the first results on δ 18 O and 2 H analysis of precipitations, cave drip waters, groundwaters from sites in Mallorca (Balearic Islands, western Mediterranean), a key region for paleoclimate studies. Understanding isotopic variability sources moisture modern climate systems is required to develop speleothem isotope‐based reconstructions. The stable composition precipitation was analysed samples collected between March 2012 2013. values are range reported by GNIP...
Abstract The advent of metal processing was one the key technological evolutions presaging development modern society. However, interplay between use and long-term changes it induced in functioning past societies remains unclear. We present a compilation global records anthropogenic atmospheric lead (Pb) spanning last 4000 years, an effective indirect proxy for reliably assessing Pb emissions directly linked to human activities. Separating this pollution signal into regionally representative...
Most paleoclimate studies of Mainland Southeast Asia hydroclimate focus on the summer monsoon, with few investigating rainfall in other seasons. Here, we present a multiproxy stalagmite record (45,000 to 4,000 years) from central Vietnam, region that receives most its annual autumn (September-November). We find evidence prolonged dry period spanning last glacial maximum is punctuated by an abrupt shift wetter conditions during deglaciation at ~14 ka. Paired climate model simulations, show...
Mangrove forests enhance Small Island Developing States' resilience to climate change, yet in 2020, a mangrove dieback impacted ~ 25% of mangrove-containing islands the Maldives. Using remote sensing, dendrology and sediment geochemistry, we document significant decrease health post-2020 (NDVI: 0.75 ± 0.09) compared pre-2020 (0.85 0.04; P < 0.0001). Dead trees showed reduced stomatal conductance (δ