Christophe Corona

French National Centre for Scientific Research | CNRS · GEOLAB Clermont-Ferrand

Glacier mass-balance reconstructions provide a means of placing relatively short observational records into a longer-term context. Here, we use multiple proxies from Pinus cembra trees from God da Tamangur combining tree-ring anatomy and stable isotope chronologies to reconstruct seasonal glacier mass balance (i.e. winter, summer and annual mass ba...

One of the purposes of dendrogeomorphic studies is to provide long and continuous reconstructions of mass movements and to detect climate-induced trends in process activity. The development of regional chronologies—in which information from different sites are aggregated—is often needed to identify process–climate relations and to overcome local-sc...

Flood marks and descriptions of past floods in archival records are valuable sources of information to complement the often short and sometimes lacunary-systematic records provided by gauge stations, especially in mountainous and smaller catchments for which the network of recording stations is still fragmentary. Yet, historical accounts of floods...

Explosive volcanism is a key contributor to climate variability on interannual to centennial timescales¹. Understanding the far-field societal impacts of eruption-forced climatic changes requires firm event chronologies and reliable estimates of both the burden and altitude (that is, tropospheric versus stratospheric) of volcanic sulfate aerosol2,3...

The primary goal of paleoflood hydrology is to estimate the frequency and magnitude of past floods. Botanical evidence, and particularly scars on trees, has been used repeatedly as paleostage indicators to reconstruct peak discharges and flood height. Yet, these reconstructions depend on the presence of visible scars on tree stems which tend to be...

Shrub dendrochronology is gaining increasing momentum in temperate high mountain regions to decipher climatic controls on current shrub expansion. Yet, a lack of consensus still persists in terms of sampling protocols, thus hampering comparability of results from different studies. For instance, serial sectioning, i.e. the sampling of multiple sect...

Introduction Mean xylem vessel or tracheid area have been demonstrated to represent powerful proxies to better understand the response of woody plants to changing climatic conditions. Yet, to date, this approach has rarely been applied to shrubs. Methods Here, we developed a multidecadal, annually-resolved chronology of vessel sizes for Rhododendr...

Mountain ecosystems are particularly sensitive to climate change, which in part causes encroachment of woody plants at the treeline ecotone, with repercussions on treeline advance and ecosystem carbon balance. Yet, studies investigating the long-term trends in radial growth as well as year-to-year response of several tree and shrub species to clima...

Dendroprovenancing provides critical information regarding the origin of wood, allowing further insights into economic exploitation strategies and source regions of timber products. Traditionally, dendroprovenancing relies on pattern-matching of tree rings, but its spatial resolution is limited by the geographical coverage of species-specific chron...

Past volcanic eruptions and their climatic impacts have been linked increasingly with co-occurring societal crises – like crop failures and famines – in recent research. Yet, as many of the volcanic cooling studies have a supra-regional or hemispheric focus, establishing pathways from climatic effects of an eruption to human repercussions has remai...

Tree rings form the backbone of high-resolution palaeoclimatology and represent one of the most frequently used proxy to reconstruct climate variability of the Common Era. In the European Alps, reconstructions were often based on tree-ring width (TRW) and maximum latewood density (MXD) series, with a focus on European larch. By contrast, only a ver...

The Arctic is warming faster than any other region on Earth. Putting this rapid warming into perspective is challenging because instrumental records are often short or incomplete in polar regions and precisely-dated temperature proxies with high temporal resolution are largely lacking. Here, we provide this long-term perspective by reconstructing p...

The 852/3 CE eruption of Mount Churchill, Alaska, was one of the largest first-millennium volcanic events, with a magnitude of 6.7 (VEI 6) and a tephra volume of 39.4–61.9 km3 (95 % confidence). The spatial extent of the ash fallout from this event is considerable and the cryptotephra (White River Ash east; WRAe) extends as far as Finland and Polan...

In mountainous regions, global warming will likely affect the frequency and magnitude of geomorphic processes. This is also the case for rockfall, one of the most common mass movements on steep slopes. Rainfall, snowmelt, or freeze-thaw cycles are the main drivers of rockfall activity, rockfall hazards are thus generally thought to become more rele...

The mid-17th century is characterized by a cluster of explosive volcanic eruptions in the 1630s and 1640s, climatic conditions culminating in the Maunder Minimum, and political instability and famine in regions of western and northern Europe as well as China and Japan. This contribution investigates the sources of the eruptions of the 1630s and 164...

The purpose of this paper is to develop an approach to estimate peat accumulation rates (PAR) over recent decades based on the age and burial depths of roots from pine sapling and to use the newly developed approach to estimate spatial variations of PAR. To this end, we sampled 120 pine saplings growing in three plots at Rėkyva peatland in Lithuani...

Paleoclimate reconstructions have identified a period of exceptional summer and winter cooling in the North Atlantic region following the eruption of the tropical volcano Huaynaputina (Peru) in 1600 CE. A previous study based on numerical climate simulations has indicated a potential mechanism for the persistent cooling in a slowdown of the North A...

The mid-17th century is characterized by a cluster of explosive volcanic eruptions in the 1630s and 1640s, deteriorating climatic conditions culminating in the Maunder Minimum as well as political instability and famine in regions of Western and Northern Europe as well as China and Japan. This contribution investigates the sources of the eruptions...

The 852/3 CE eruption of Mount Churchill, Alaska, was one of the largest first millennium volcanic events, with a magnitude of 6.7 (VEI 6) and a tephra volume of 39.4–61.9 km3 (95 % confidence). The spatial extent of the ash fallout from this event is considerable and the cryptotephra (White River Ash east; WRAe) extends as far as Finland and Polan...

This paper reports on climate-induced growth changes in relict, low-altitude mountain pines ( Pinus uncinata Mill. ex. Mirb.) from two refugia with cold microclimates located in the Northern French Alps. The P. uncinata stands analyzed grow at the lower bound of their ecological limit and are thus thought to be sensitive indicators of ongoing clima...

Past volcanic eruptions and their climatic impacts have been linked increasingly with co-occurring societal crises – like crop failures and famines – in recent research. Yet, as many of the volcanic cooling studies have a supra-regional or hemispheric focus, establishing pathways from climatic effects of an eruption to human repercussions has remai...

Significance Snow avalanches represent a major threat in mountain environments, where they cause damage to critical infrastructure and claim hundreds of lives every year. Here, we document an unambiguous upslope migration of snow avalanches with climate change, a physical mechanism whose existence could previously not be demonstrated. In the Vosges...

The spatial and temporal quantification of rockfall frequency remains a major challenge in mountain environments, especially also in terms of rockfall management. Approaches that have been used traditionally to quantify rockfall frequency include historical records, remote sensing, or in situ monitoring, but have been shown repeatedly to suffer fro...

Paleoclimate reconstructions identify a period of exceptional summer and winter cooling in the North Atlantic region following the eruption of the tropical volcano Huaynaputina (Peru) in 1600 CE. Numerical climate simulations indicate a possible eruption-induced mechanism for the persistent cooling in a slowdown of the North Atlantic subpolar gyre...

In the European Alps, air temperature has increased almost twice as much as the global average over the last century and, as a corollary, snow cover duration has decreased substantially. In the Arctic, dendroecological studies have evidenced that shrub growth is highly sensitive to temperature – this phenomenon has often been linked to shrub expans...

Tree-ring chronologies underpin the majority of annually-resolved reconstructions of Common Era climate. However, they are derived using different datasets and techniques, the ramifications of which have hitherto been little explored. Here, we report the results of a double-blind experiment that yielded 15 Northern Hemisphere summer temperature rec...

Tree-ring chronologies underpin the majority of annually-resolved reconstructions of Common Era climate. However, they are derived using different datasets and techniques, the ramifications of which have hitherto been little explored. Here, we report the results of a double-blind experiment that yielded 15 Northern Hemisphere summer temperature rec...

To overcome the lack of historical archives at active rockfall environments, dendrogeomorphic techniques have been used extensively on forested slopes since the early 2000s and several approaches developed to extract rockfall signals from tree-ring records. Given the unpredictable nature of rockfall, these reconstructions are, in principle, of grea...

Volcanic eruptions are a key source of climatic variability, and reconstructing their past impact can improve our understanding of the operation of the climate system and increase the accuracy of future climate projections. Two annually resolved and independently dated palaeoarchives – tree rings and polar ice cores – can be used in tandem to asses...

In mountain environments, precise rockfall risk evaluation is crucial to reduce death tolls and costs. However, to date, existing rockfall risk assessment procedures remain scarce, as they focus only on existing elements at risk and with the damage expectation as sole risk measure. Here, we propose an approach to evaluate the distribution of damage...

In mountain environments, precise rockfall risk evaluation is crucial to reduce death tolls and costs. However, to date, existing rockfall risk assessment procedures remain scarce, as they focus only on existing elements at risk and with the damage expectation as sole risk measure. Here, we propose an approach to evaluate the distribution of damage...

Les chutes de blocs représentent un aléa majeur dans les zones montagneuses, menaçant infrastructures collectives, zones urbanisée et vies humaines. Les conséquences de ces événements peuvent être importantes pour les collectivités locales ainsi que les pouvoirs publics, qui restent démunis en matière de méthode de diagnostic et d'analyse du risque...

Depuis deux décennies, de nombreuses publications scientifiques ont mis en évidence les impacts du changement climatique sur la fréquence des chutes de pierres dans les parois englacées de haute altitude. À plus basse altitude, les inventaires rares et incomplets existants n’ont pas permis d’identifier un impact significatif de l’augmentation des t...

Les bases de données événementielles recensant les chutes de blocs et leurs conséquences restent peu développées. Dans les Alpes françaises, un territoire pourtant propice et où les enjeux sont nombreux et diversifiés, l’information existante est dispersée et hétérogène. Dans le contexte du Projet National C2ROP, un premier effort de capitalisation...

Newly developed millennial δ13C larch tree-ring chronology from Siberia allows reconstruction of summer (July) vapor pressure deficit (VPD) changes in a temperature-limited environment. VPD increased recently, but does not yet exceed the maximum values reconstructed during the Medieval Warm Anomaly. The most humid conditions in the Siberian North w...

Volcanic eruptions are a key source of climatic variability and reconstructing their past impact can improve our understanding of the operation of the climate system and increase the accuracy of future climate projections. Two annually resolved and independently dated palaeoarchives – tree rings and polar ice cores – can be used in tandem to assess...

Recently revised ice core chronologies for Greenland have newly identified one of the largest sulfate deposition signals of the last millennium as occurring between 1108 and 1113 CE. Long considered the product of the 1104 CE Hekla (Iceland) eruption, this event can now be associated with substantial deposition seen in Antarctica under a similarly...

Premise: Mountain ecosystems are particularly sensitive to climate change. However, only a very small number of studies exist so far using annually resolved records of alpine plant growth spanning the past century. Here we aimed to identify the effects of heat waves and drought, driven by global warming, on annual radial growth of Rhododendron fer...

Dendrogeomorphic analyses provide long and continuous chronologies of mass movements that are useful for the detection of trends related to climate change. Socio-environmental changes can, however, induce non-stationarities. This study addresses the following questions: (1) How does the evolution of forest cover induce non-stationarities in tree-ri...

Rockfall release is a rather unpredictable process. As a result, the occurrence of rockfall often threatens humans and (infra)structures. The assessment of potential drivers of rockfall activity therefore remains a major challenge, even if the relative influence of rainfall, snowmelt, or freeze–thaw cycles have long been identified in short‐term mo...

Stratospheric volcanic eruptions have had significant impacts on the radiation budget, atmospheric and surface temperatures, precipitation and regional weather patterns, resulting in global climatic changes. The changes associated with such eruptions most commonly result in cooling during several years after events. This study aimed to reveal eco-p...

The systematic killing of trees is usually aimed at eradicating pests or alien plant species susceptible to harm existing natural ecosystems. In some cases, trees may become the subject of dispute between neighbors, which sometimes ends in tree death after months or years of dispute. In this paper, we analyze a case of clandestine tree killing and...

Due to the scarcity of reliable palaeoecological and climatic proxy records from the Eastern Baltic covering the Holocene, there has been increased interest for multi-proxy studies in the region to detect local to regional environmental changes. The Čepkeliai wetland complex, SE Lithuania, provides an uninterrupted Holocene sediment sequence, which...

À travers les paysages splendides des montagnes suisses, autrichiennes, françaises et allemandes, ce documentaire accompagne tout au long d’une saison hivernale des sauveteurs, des scientifiques et des chercheurs qui se consacrent aux sommets glacés et à leurs dangers.

In the current context of anthropogenic global warming, one of the purposes of dendrogeomorphic analyses is to provide long and continuous chronologies of mass movements, so as to detect potential trends or shift related to increasing temperatures. However, on documented slopes, the comparison between historical archives and tree-ring records sugge...

The rockfall phenomenon is deined as a rock block that detaches from a vertical or sub-vertical clif and travels down the slope in rapid motions. Every year, some rockfalls reach urbanized areas, causing damage to structures and injuring people. In this context, a precise rockfall risk analysis has become essential for authorities and stakeholders....

Stratospheric volcanic eruptions have far-reaching impacts on global climate and society. Tree rings can provide valuable climatic information on these impacts across different spatial and temporal scales. To detect temperature and hydroclimatic changes after strong stratospheric Common Era (CE) volcanic eruptions for the last 1500 years (535 CE un...

This paper aims to study what influence different meteorological parameters have on the radial tree growth of Scots pine (Pinus sylvestris L.) in peat and mineral soils, as well as to make predictions of radial tree growth responses to changing climate based on various future climate projections. Four Lithuanian peatland complexes representing diff...

Due to intense urban sprawl in rockfall-prone areas, a precise rockfall risk assessment has become a crucial issue for public authorities and stakeholders. In this context, quantitative risk analysis (QRA) procedures, accounting for the specificities of the rockfall process, have been developed. For the last few decades, several studies have examin...

En région de montagne, les chutes de blocs représentent un aléa majeur qu’il convient de caractériser par le biais de sa fréquence, de son intensité (énergie) et de sa propagation (distance d’arrêt). Bien que particulièrement complexe, en raison du caractère diffus de cet aléa et des lacunes existant dans les archives historiques, cette caractérisa...

A large amount of well-preserved timbers was found during several archaeological excavations of the Faravel mining site (Southern French Alps, between 1950- and 2150m a.s.l.). 232 of these timbers were sampled for dendrochronological analysis and 67% of them were dated. These 156 larch (Larix decidua Mill.) series, crossdated against existing refer...

A better understanding of the respective role of key climatic variables on tree growth is crucial for an accurate assessment of how ongoing global changes may affect both dynamics and distribution of forest tree species in the future. The aim of this study was (i) to explore growth patterns of European larch (Larix decidua Mill.) through a network...