Centre for the Observation and Modelling of Earthquakes, Volcanoes and Tectonics
NERC Open Research ArchiveNot a member yet
55023 research outputs found
Sort by
Global observations of land-atmosphere interactions during flash drought
Get PDFFlash droughts, which intensify on subseasonal-to-seasonal (S2S) timescales (2 weeks–2 months), cause severe and sudden impacts on agriculture, ecosystems and economies. To evaluate and improve S2S forecasts of flash drought, we need to understand the land-atmosphere coupling processes that are critical to flash drought development, specifically the feedbacks between soil moisture and evapotranspiration. Previous investigations of flash droughts have either focused on specific regions or relied on global reanalysis datasets, which have known shortcomings in their representation of land-atmosphere interactions. Here, we use a variety of global long-term products of daily satellite observations to explore the evolution of the surface energy balance during flash droughts over the period 2000–2020. We investigate the differences between flash droughts with stronger and weaker land-atmosphere coupling, and assess feedbacks from the land surface to near-surface air temperatures during the events. Events with stronger evaporative stress are associated with perturbations in the surface energy budget for 4 months both before and after drought onset, indicating the importance of precursor land conditions for S2S predictability. For three semi-arid regions in Africa, we show that increased sensible heat flux feeds back to increase peak air temperatures during flash droughts. We also use Vegetation Optical Depth (VOD), a proxy for vegetation water content, to demonstrate that lower VOD 1–2 months before flash drought onset is linked to increased air temperatures during the peak of the drought in some regions. For example, in West African summer, 12 % of flash droughts with precursor VOD anomalies in the highest quartile experience a peak air temperature anomaly >1.5σ, whereas this increases to 27 % for events with precursor VOD anomalies in the lowest quartile. This shows that globally-observable land surface conditions could provide useful information to S2S forecasts and motivates further assessment of land-atmosphere interactions in these forecasting models using observational datasets at the global scale
Spatio-temporal melt and basal channel evolution on Pine Island Glacier ice shelf from CryoSat-2
Get PDFIce shelves buttress the grounded ice sheet, restraining its flow into the ocean. Mass loss from these ice shelves occurs primarily through ocean-induced basal melting, with the highest melt rates occurring in regions that host basal channels – elongated, kilometre-wide zones of relatively thin ice. While some models suggest that basal channels could mitigate overall ice shelf melt rates, channels have also been linked to basal and surface crevassing, leaving their cumulative impact on ice shelf stability uncertain. Due to their relatively small spatial scale and the limitations of previous satellite datasets, our understanding of how channelised melt evolves over time remains limited. In this study, we present a novel approach that uses CryoSat-2 radar altimetry data to calculate ice shelf basal melt rates, demonstrated here as a case study over Pine Island Glacier (PIG) ice shelf. Our method generates monthly digital elevation models (DEMs) and melt maps with a 250 m spatial resolution. The data show that near the grounding line, basal melting preferentially melts a channel's western flank 50 % more than its eastern flank. Additionally, we find that the main channelised geometries on PIG are inherited upstream of the grounding line and play a role in the formation of ice shelf pinning points. These observations highlight the importance of channels under ice shelves, emphasising the need to investigate them further and consider their impacts on observations and models that do not resolve them
Integrated multi-omics highlights alterations of gut microbiome functions in prodromal and idiopathic Parkinson’s disease
Get PDF•Background: Parkinson’s disease (PD) is associated with gut microbiome shifts. These shifts are mainly described at taxonomic level, but the functional consequences remain unclear. To obtain insight into the functional disruptions of the gut microbiome in PD, we used an integrated multi-omics approach, comparing gut microbiomes of individuals with PD, prodromal PD, and healthy controls.
•Results: Meta-metabolomics, the most discriminatory and robust omics level, was selected to Guide the analysis. We identified 11 metabolites that were differentially abundant between the groups, among which β-glutamate was increased in PD and prodromal PD, and correlated with the transcriptional activities of Methanobrevibacter smithii and Clostridium spp. We identified decreases in transcripts, but not in gene abundances, related to glutamate metabolism, bile acids biosynthesis, chemotaxis, and flagellar assembly in PD, particularly in keystone genera such as Roseburia , Agathobacter , and Blautia . Our findings, integrated into the Expobiome map, reveal multifactorial microbiome alterations which converge with PD pathways.
•Conclusion: Our study highlights the apparent disruption of microbial gene expression in PD, particularly in genes associated to mobility. Moreover, we showcase the importance of investigating the gut microbiome’s functional dimensions to better resolve microbiome-host interactions in health and disease
Quantitative ecology reveals scale-dependent structural processes of the Antarctic benthos through time
No full textModern day benthic community composition and distribution in the Southern Ocean are
influenced by a variety of environmental and evolutionary factors across different spatial
scales. Depth, temperature, salinity, and sea ice impact community structure at large spatial
scales (e.g., > 60 km). Far less is known about the interactions between taxa and
environment at smaller scales, particularly due to the difficulties in collecting polar data.
The study of biodiversity typically requires the direct collection of material, including at
the larval stage. However, benthic sampling in the Southern Ocean is extremely
challenging, and traditional sampling methods also cannot be deployed in regions of high
topographic complexity. Advances in camera technology, such as towed camera systems,
have now allowed for extensive observation in previously under-sampled areas. While
photographs are single snapshots in time, ecological inferences can be made of the
community as a whole, allowing us to make in situ observations of these otherwise difficult
to sample ecosystems.
In this thesis I explored ecosystem structure in the Weddell Sea across a number of spatial
and temporal scales using seabed photographs and fossil collections. I first investigated
coexistence mechanisms and competition for two solitary scleractinian cup coral
populations at the centimetre scale on the rocky slopes of Powell Basin (~2000 m depth).
Using Spatial Point Process Analyses I found that these corals likely produced larvae that
settle near their parents, and that the one coral morph changed its reproductive behaviour
when sympatric to the other morph. This dispersal plasticity likely allowed for the
coexistence of ecologically similar taxa at small spatial scales, thereby enhancing alpha
diversity.
Next, I examined benthic function at the ecosystem level in two habitats in the Weddell
Sea: the rocky slopes of Powell Basin and the shallow muddy bottoms (~450 m water
depth) near the Antarctic Peninsula. On the rocky Powell Basin slope, I discovered a dense,
speciose epibenthic community dominated by suspension and filter feeders. Bayesian
Network Inference showed that no single group controlled the network structure. Unlike in
very shallow Antarctic systems, predators, especially starfish, though present, had little
ecological impact, showing that predator-prey interactions were not a structural factor in
4
the Powell Basin. In contrast, the soft substrate community was less dense and exhibited
limited interactions, potentially due to sampling limitations, and was mediated only by
dropstones.
Finally, I investigated large scale benthic ecosystem complexity in deep time, using a
minimally time- and habitat-averaged fossil record. I focused on the latest Maastrichtian
66 million years ago, just before the Cretaceous-Paleogene mass extinction, a global event
following which the modern Antarctic fauna evolved. I analysed fossils from the López de
Bertodano Formation of Seymour Island and found increasing metacommunity complexity,
possibly driven by climate warming, over the 4 million years leading up to the extinction.
This study provided valuable context for understanding the sudden impact of the extinction,
and the ecological changes that occurred during this global evolutionary shift
Attributing a deadly landslide disaster in southeastern Brazil to human-induced climate change
Get PDFPetrópolis was hit by a devastating disaster in February 2022, when it rained 252.8 mm within 3 h, leading to 200 lost lives and hundreds of people being displaced. Here, we aimed to attribute the extreme rainfall event that led to several landslides in Petrópolis, assess how Land Use and Land Cover changes (LUCC) from 1985 to 2021 contributed to it, and quantify their socioeconomic impacts. For this, we compared natural-only forcing (NAT) and natural and anthropogenic forcing combined (ALL) scenarios of the HadGEM3 ensemble models with observation data. We computed the trends in LUCC and quantified the landslide's socioeconomic impacts from official datasets. Human-induced climate change made this extreme event 45 % and 71 % more likely in short and long-term rainfall, respectively. Recurrence period dropped from 2.36 years (NAT) to 1.63 years (ALL) in the short-term and from 5.66 years (NAT) to 3.31 years (ALL) in the long-term. Landscape trends show an increase in forest formations, but unprotected hilltops that collapsed presented more than 40 % of their area as farming. The total economic loss was more than USD 22 million, with 1 078 people directly affected. The study's findings are valuable in understanding how changes in extreme weather events and land use are affecting our society. We highlight the need for adaptation measures and for more research addressing the attribution of extreme events, especially those associated with disastrous landslides
Year 3 progress report for the BGS International Geoscience R&D programme
Get PDFThis report provides a progress review of Year 3 of the NERC National Capability (NC) funded BGS International Geoscience Research and Development (IGRD) programme. The IGRD programme runs from 2022-26 and had an initial budget of £11.929M; following a mid-programme revision, the budget has been reduced to £8.3M
A behavioural approach to key area identification in seabirds for threat mitigation and spatial management
Get PDF•Background: Identifying key areas of animal distribution using individual movement data is fundamental for conservation planning, threat mitigation, and spatial management. Methodologies which define these areas based on measures of high density and abundance may overlook spatial heterogeneity in behaviour-specific distributions. This is particularly relevant for behaviours that occur at lower densities but are associated with increased exposure to specific environmental threats. We used a dataset of 566 GPS tracked individuals and 14 colonies of a vulnerable species of seabird, the black-legged kittiwake ( Rissa tridactyla ), to compare two methods for delineating key areas. The first method applies kernel density estimates, based on 50% (‘core area’) utilisation distributions, to all movement data during an at-sea trip. This reflects a widely used density-based approach to identify high-use spatial areas. The second method incorporates hidden Markov modelling to classify movement data into three dominant behaviour states: resting, foraging, and transiting, to identify behaviour-specific high-use areas. We then compare population-level estimates of key areas based on each method using the BirdLife International Key Biodiversity Area framework. We also explore how the selection of an intermediate (70%) and home range (95%) utilisation distribution influences the capture of different behaviours.
•Results: We found that individual-level kernel density estimates based on core areas of all movement data fail to adequately capture the core distribution of transiting, a widespread and dispersed behaviour. Moreover, population-level estimates of key areas derived from transiting behaviour are significantly larger than those identified using all tracking data, suggesting that conventional methods likely underestimate exposure to threats encountered during transit. Conversely, key areas for resting and foraging behaviour are more spatially constrained than those derived from all movement data, implying that behaviour-specific analyses may improve the precision of conservation planning. Both individual and population-level key area estimates based on larger utilisation distributions (i.e. 75% and 95%) better capture the distribution of transiting behaviour as these larger distributions probabilistically encompass a greater fraction of observed movement trajectories.
•Conclusion: These results highlight the importance of labelling movement data by behavioural state to enhance the utility of GPS data for conservation applications. By incorporating behavioural state differentiation into spatial analyses, threat exposure assessments can be refined to focus conservation resources more effectively. Furthermore, this approach has direct implications for environmental impact assessments, particularly in the context of expanding marine industries such as offshore renewable energy developments
Mineral planning factsheet : industrial sand future markets
Get PDFThis factsheet provides an overview of UK Industrial sand markets. It is one of a series on economically important minerals that are extracted in Britain and is primarily intended to inform the land-use planning process. It is not a statement of planning policy or guidance; nor does it imply Government approval of any existing or potential planning application in the UK administration
Effects of environmental conditions on mate fidelity in a socially monogamous seabird
Get PDFIn iteroparous, socially monogamous species, individuals vary in the extent of mate fidelity across breeding attempts, often with important fitness consequences. Numerous studies have demonstrated intrinsic drivers of mate fidelity, notably previous breeding success and parental age. Environmental conditions may also influence mate fidelity, and the habitat-mediated hypothesis predicts that fidelity will be lower when environmental conditions are poor. However, limited testing of this hypothesis has been undertaken in longitudinal studies of single populations. Furthermore, studies have mainly focused on environmental conditions during the breeding season, yet conditions prior to breeding may be important for mate fidelity because this is a critical period for pair bond formation. We investigated the effects of prebreeding environmental conditions (onshore wind component and sea surface temperature) on mate fidelity over a 20-year period in the socially monogamous, iteroparous, long-lived marine bird, the European shag, Gulosus aristotelis. Average fidelity rate varied three- to four-fold between years. Mate fidelity was affected by prebreeding environmental conditions, being lower when onshore winds were more prevalent and sea surface temperature was higher. However, mate fidelity was more strongly affected by intrinsic factors, with higher rates when breeding success in the previous attempt and population density were higher, and among older females and middle-aged males. We found that mate fidelity affected timing of breeding, with faithful pairs laying earlier, and early laying pairs bred more successfully, but there was no independent effect of mate fidelity on breeding success. Our results support the habitat-mediated hypothesis whereby prebreeding environmental conditions affect individual pairing decisions. Given environmental conditions are predicted to change globally, further investigation of their impact on aspects of social behaviour in a range of species is warranted
The genome sequence of the bee moth, Aphomia sociella (Linnaeus, 1758) (Lepidoptera: Pyralidae)
Get PDFWe present a genome assembly from an individual female Aphomia sociella (Bee moth; Arthropoda; Insecta; Lepidoptera; Pyralidae). The assembly contains two haplotypes with total lengths of 681.66 megabases and 601.52 megabases. Most of haplotype 1 (99.63%) is scaffolded into 30 chromosomal pseudomolecules, including the W and Z sex chromosomes. Haplotype 2 was assembled to scaffold level. The mitochondrial genome has also been assembled, with a length of 15.38 kilobases. This assembly was generated as part of the Darwin Tree of Life project, which produces reference genomes for eukaryotic species found in Britain and Ireland
Data sources:
Access Repository Dashboard
Do you manage NERC Open Research Archive? Access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard!