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The rationale behind constructing this new database is to create a comprehensive catalogue including all known or identified collapse calderas. The availability of accurate and comprehensive statistics is vital to understand these volcanic structures . Thus, this extensive data compilation should be an accessible and useful tool for studying and understanding caldera collapse processes . The final aim of the CCDB is to update the current field based knowledge on calderas, by merging together the abovementioned databases and complementing them with the existing peer-reviewed articles on calderas. This database does not include all the calderas of the world but tries to be representative. The current files is the latest update corresponding to papers published up to 2019.

Tenerife island (Canary Islands, Spain), home to nearly a million inhabitants and attracting over 5 million tourists annually, hosts one of Europe's potentially most hazardous volcanic systems. Current volcanic activity on the island is primarily located in its central region comprising the Teide-Pico Viejo volcanic complex, and extends along the Santiago del Teide and Dorsal ridges towards the NW and NE, respectively. Understanding the volcanic stratigraphy, petrology, and geochemistry of the different eruptions within the central complex and their correlation with the rift systems is crucial to comprehend how this complex volcanic system will behave in the future, thereby improving hazard assessment for the island. In this study, we provide a comprehensive review of the geochemistry of eruptive products associated with events that occurred in the area over the last 180ka, following the El Abrigo eruption, the island's latest caldera-forming event. Special emphasis is given to Holocene eruptions sourced at the Teide-Pico Viejo volcanic complex and the two adjacent rifts. To facilitate this, we have constructed the GeoTeRi database, which includes an exhaustive compilation of whole-rock major and trace elements analyses, along with isotopic data available in the literature (over 49 consulted references). Additionally, a review of the chronostratigraphy of the eruptions included in the database was conducted, drawing on published volcanostratigraphic maps and/or existing radiometric data. The GeoTeRi database currently includes information from 651 rock samples, comprising over 500 major and trace elements analyses, and 176 isotopic analyses. This database aims to serve as a tool for reconstructing the geochemical evolution of the active volcanic system on the island of Tenerife and it will provide a starting point for future studies. Additionally, a detailed statistical analysis of this database is planned to evaluate its robustness, the representativeness of the an

El Teide National Park on the island of Tenerife (Canary Islands) is home to one of the most spectacular volcanic landscapes in the world. Although the conservation of its geodiversity is not a major problem given that it is governed by strict Spanish laws on geoconservation and is, in addition, a UNESCO World Heritage site, the diffusion of its geological values among the general public is more of a challenge due to the lack of any specific program for scientific knowledge transfer to visitors. The volcanological history of this national park needs to be transmitted in a clear and comprehensible fashion. However, the lack of adequate outreach material and of any coherent and consistent narrative regarding the significance of the island’s geological heritage makes it difficult to incorporate its geological history into the minds of visitors. This engenders a perception of its geoheritage that underestimates its importance. To remedy this misconception, the following tasks need to be carried out: (1) a compilation of all current scientific knowledge of the geology and volcanology of the area; (2) the identification of key geosites that offer the best means of understanding the history and evolution of this volcanic area; (3) the production of outreach and diffusion programs specifically designed to transmit this scientific knowledge to the general public; and (4) the establishment of permanent training programs for park and tourist guides that will guarantee the efficacy of this knowledge transmission. This contribution summarizes the main aspects of the geological history of El Teide National Park, identifies the elements that best exhibit its geological heritage, discusses the main problems observed in transmitting these geological values to visitors, and provides some clues as to how to face up to these challenges.

Tenerife, one of the active oceanic island volcanoes in the Canary Islands, located in the eastern Atlantic Ocean off northwest Africa, is the second largest intraplate oceanic island volcanic system after Hawai'i but is more complex and represents a different and more evolved end-member to Hawai'i in the spectrum of oceanic island volcanic systems. Tenerife began life as a mafic oceanic shield volcano at ~12 Ma, erupting (picro)basalt, basanite, hawaiite, mugearite, benmoreite series lavas of the Older Basaltic Series. These were derived from a spatially variable mantle plume source with varying degrees of magma-lithosphere interaction and fractional crystallisation. At ~3.05 Ma an evolved phonolitic magma system began to develop under the centre of the island. That led to the building of an initial summit effusive and explosive stratovolcano system (the Las Cañadas edifice) represented by the poorly understood Lower Group, followed by development of 3 cycles of explosive phonolitic caldera forming activity (Ucanca, Guajara, Diego Hernández) of the Upper Group, from 1.66 Ma to 0.19 Ma, each cycle separated by ~180 kyr (the recharge interval?). Phonolite genesis is complex, involving fractional crystallisation, partial melting of island crust including syenitic plutons, and recycling of crystal mushes. Three coalesced explosive calderas are preserved at the summit of Tenerife, constituting the Las Cañadas Caldera Complex. Since 0.19 Ma two stratovolcanoes (Teide, Pico Viejo) have been growing along the northern rim of the caldera complex, becoming more phonolitic from basaltic beginnings and more explosive, perhaps heralding the beginning of a new explosive cycle. Simultaneously shield building basaltic volcanism has continued on the flanks to historic times through multiple monogenetic eruptions along the linear northwestern and northeastern rift zones, and a more diffuse southern volcanic zone. Volcanic eruption styles have included fissure fed basaltic shield she

This article evaluates the strategy approved in 2000 for managing the geological heritage of La Garrotxa Volcanic Zone Natural Park (PNZVG). The conservation of geodiversity and geological heritage provides a foundation for the conservation of other types of heritage, for example, in the fields of forestry, agriculture, industry, and urban development. The human imprint on this natural Park is significant, and most of the land it contains is privately owned and is commercially productive. Consequently, the management of its volcanic strata is a highly complex affair as preservation must be compatible with the types of land use that dominate in this protected area. The PNZVG’s strategy for managing its geological heritage stems from the need to promote the efficient conservation of its values based on knowledge and greater awareness of this volcanic field. Quaternary volcanic fields such as this one—which may have experienced volcanic activity in the Holocene—are characterised by their excellent state of conservation, which ensures that their volcanic morphologies and the geological processes that have created them are fully visible. In 2000, the natural Park became one of the first protected areas in the world to put into practice a strategy for preserving the geological heritage of its volcanoes. Twenty years later, an accurate evaluation of this process will help other volcanic zones design their own strategies for preserving their geological heritage. To sum up, both challenges and objectives are necessary for ensuring good management of a protected area such as this.

Hazard assessment of remote volcanic islands provides many challenges compared to other volcanoes and volcanic fields. Here we present the first systematic volcanic hazard assessment of Jan Mayen Island, a remote island located in the North-Atlantic Ocean and home to the northernmost active subaerial volcano in the world (Beerenberg Volcano), and we discuss some of the challenges and characteristics of performing a volcanic hazard assessment of a remote volcanic island. Jan Mayen has had at least five eruptions since its discovery at the start of the 17th century. Its Holocene volcanism is mainly characterized by eruptions with styles ranging from Hawaiian to Strombolian, but also by lava domes and Surtseyan eruptions. Based on field data, remote images, topographic data, past data, and computer simulations, our study evaluates the spatial probability of new vents opening, estimates eruption recurrence rates, simulates various eruption scenarios, and produces hazard maps for the different scenarios. This work shows where the hazards of ash fall, and lava flows are more likely to affect the built infrastructure on Jan Mayen Island. This hazard assessment will assist emergency planning and the determination of future land use on the island.

The El Abrigo member of the Diego Hernández Formation (Tenerife, Canary Islands) represents the final (170 ka) and most voluminous eruption (>20 km3 DRE) of the last cycle of explosive activity of the Las Cañadas volcano. It is a dominantly phonolitic ignimbrite containing both mafic and banded pumices, suggesting that magma mixing played an important role in triggering the eruption and modulating eruptive dynamics. Here we use petrology, together with glass and mineral geochemistry of enclave-rich mafic scoriae, banded and phonolitic pumices from El Abrigo ignimbrite, to shed light on the pre-eruptive storage conditions and processes governing magma ascent and interaction dynamics and to provide a first-order assessment of the contribution of magma mixing and crystal mush melting to the dynamics of this eruptive event. The distribution of major elements in glasses is consistent with diffusive exchange between the interacting melts whereby Na transfers from the phonolite to the tephriphonolitic melt. However, V, Zr, Ba and Eu suggest a complex scenario in which an intruding tephritic to phonotephritic magma interacted with two distinct zones of a phonolitic magma chamber, one occupied by a crystal rich, low-Zr and high Ba phonolite, and the other by an evolved, crystal poor, high-Zr phonolite. These results, coupled with mineral-melt thermobarometry, allow us to reconstruct the Las Cañadas plumbing system at the end of the Diego Hernández cycle, and to evaluate the contribution of cumulate mush melting and magma mixing in as follows: (1) the parental tephritic magma was stored at or near the Moho (410-450 MPa) at 1050°C where it was periodically replenished by more primitive basanitic magma; (2) upon ascent, the tephrite intruded into a shallow and zoned phonolitic storage system, triggering the disruption of a crystal mush in its base, and (3) subsequently interacted with a crystal-poor zone within the reservoir. Energy balance evaluations suggest that relative maf

The Puig de la Banya del Boc volcano is located in the southern sector of the Garrotxa Volcanic Field in the NE of the Iberian Peninsula and is part of the European Cenozoic Rift System. This monogenetic volcano was constructed on a hard basement of Paleozoic metamorphic rocks and shows a complex eruptive succession with phreatomagmatic, Strombolian, and effusive phases. Similar to other volcanoes of the same volcanic field, the succession of deposits of the Puig de la Banya del Boc volcano reveals the influence of the substrate, upon which the volcano forms, on eruption dynamics. In this case, the Paleozoic basement and its particular hydrodynamic properties controlled the way in which magma/water interactions occurred throughout the eruption. This volcano is coeval with the Clot de l'Omera, a small maar-type edifice that was emplaced on a conjugate fault, which belongs to the same fault system.

The geological survey has been carried out in El Hierro with the aim to produce a new Geological Map at 1:12,500 scale for the Southern Rift. Almost 70 km2 have been mapped providing a detailed stratigraphic and volcano-tectonic reconstruction of its evolution. Our work focused on the last Rift Volcanism phase, where hundreds of cinder cones, associated with thin lava flows, cover most of the island’s surface. Lava flows fields (40), monogenetic volcanic edifices (>90), and volcano–tectonic structures (69), such as dykes, eruptive fissures, and faults have been surveyed and stored in the Geological Map. The map poses fundamental constraints on the Southern Rift geological evolution, mainly concerning its recent activity and allowing the definition of 4 main stages during the last 40 ka. Moreover, this 1:12,500 scale detailed map represents a primary tool for the volcanic hazard assessment of the Island, volcanic monitoring, urban planning, and further stratigraphic data-based investigations.

Active volcanoes are key laboratories to carry out detailed research -and monitoring- about the history of magmas before, during and after eruptions. Tagoro, the submarine active vol- cano at El Hierro Island (Canary archipelago), is a highly favorable case to assess and monitor its daily ongoing behaviour, as well as to study the links between the processes of magma genesis occurring at depth and their derived eruptive events at the surface. In this interdisciplinary research we combine new results of classical petrology (petrography, geochemistry, and thermodynamics) on the volcanic products expelled by Tagoro during the 2011–2012 eruption, with a high- resolution (5 m grid) bathymetry model car- ried out during 2017, and recent data from magnetometry, to refine the current knowl- edge of this eruption. Our results mainly reveal (i) slight magma differentiation and mixing processes at c. 12 km depth during a continuous eruptive pulse; (ii) a similar mag- matic evolution and residence times at depth between previous and 2011–2012 eruptions on the island; (iii) an insignificant interaction of external fluids with the magma at depth or within the ascent conduit; (iv) a present-day magnetometric anomaly under the Tagoro’s area; (v) a minimum volume estimate for the magma withdrawn from the plumbing system at depth.

Volcanic eruptions caused by magma-water interaction depend on the substrate, the hydrogeological parameters of the aquifer and the proportions and extent to which magma and water interact. The substrate also affects the resulting overall shape of the volcano and gives rise to a wide range of morphologies. The Puig de la Banya del Boc (PBB), which belongs to the Garrotxa Volcanic Field (GVF), is a monogenetic cone with a complex eruptive succession with phreatomagmatic, Strombolian and effusive phases. Deposits from this volcano reflect the clear influence of the substrate on the eruptive dynamics highlighting how this type of activity is not uncommon in the GVF. 30/1/23, 13:48 Resúmenes https://raugm.org.mx/paricutin80/resumenes/account/view.php?abstractID=43 2/2 The aim of the study consists on the reconstruction of the eruptive history of the PBB volcano through lithostratigraphic, sedimentological and stratigraphic analysis of its deposits. The results show that the PBB volcano and its contemporary Clot de l¿Omera maar-crater are located on a conjugate faults system. Both volcanoes formed during the same eruption that was controlled by the interaction of magma with shallow water tables at different depths in the Paleozoic substrate. These crystalline materials are characterized by low permeability and an irregular distribution of internal heterogeneities such as fractures, schistosity, and the presence of dikes. This resulted in an irregular accumulation of groundwater that yielded an irregular magma/water interaction during the eruption. This demonstrates how a single eruption can produce a complex sequence of eruptive styles and depositional processes. The Puig de la Banya del Boc eruption affected an area of at least 15 km2. Deposits include dense and dilute PDCs, ash fall and lava flows up to 2 km from the vent. This work represents a further step to improve the knowledge of phreatomagmatism and the related hazards in the GVF.

The Garrotxa Volcanic Field (GVF), northeast of the Iberian Peninsula, is one of the monogenetic Quaternary volcanic fields associated with the intraplate European Cenozoic Rift System. The GVF covers an area of about 600 km2 and is located between the cities of Olot and Girona. This basaltic volcanic field ranges in age from 0.7 Ma to early Holocene and the activity 14/02/2023, 10:18 Resúmenes https://raugm.org.mx/paricutin80/resumenes/sessions/abstract.php?abstractID=19&source=session 2/2 was highly variable, mainly controlled by regional normal faults generated during the Neogene extension. The GVF is considered an active monogenetic field since the last eruption dated 11,000-13,000 years ago. Scoria cones represent the most common landforms of the GVF with subordinate maars and tuff rings/cones, with over 50 scattered eruptive vents. Most of the volcanoes are located in the northern sector between the towns of Olot and Santa Pau and they stand on folded Eocene basement. Volcanoes located in southern area of the field, close to the city of Girona, stand mainly on a fractured Paleozoic basement. The objective of this work is to identify eruptive processes and the geomorphic evolution of volcanic edifices by morphometric analyses, supported by field observations. The best volcanic structures in the GVF have been selected due to their well-preserved morphologies. Cones (Wco) and craters (Wcr) mean diameters, as well as cones maximum height (Hmax), maximum crater depth (Dcrmax) and external slope of the cones (Smedian) have been measured. Scoria cones have Hmax/Wco ratios with values between 0.04 and 0.17 and Smedian between 8° and 29°. Edifices with alternance of magmatic and hydromagmatic activity show values with Hco/Wco ratios between 0.09 and 0.15 and Smedian between 19° and 26°. Tuff rings/maars have the lowest Hmax/Wco ratios that are between 0.03 and 0.14 and Smedian between 8° and 26°. This study shows that basic shape parameters in combination with slope an

The behaviour of Group I and II elements during the petrogenesis of felsic igneous rocks is largely controlled by feldspar-liquid relationships. Numerous experimental studies have addressed plagioclase/melt element partitioning, with fewer studies devoted to potassium feldspar, and very few to albite-rich ternary-composition feldspar (An ~ Or < Ab). Feldspars, glasses, and whole rocks in such suites may exhibit strong enrichments and depletions that can be used to track magmatic processes. Here, we review experimental feldspar/melt partitioning data for Ba, Sr, and Rb for all feldspars. Regression of available data provides expressions that appear to adequately model the compositional dependence of partition coefficients for albite-rich compositions. We have applied this model to feldspar and melt compositions of the products of several Holocene eruptions (Pico Viejo C, Pico Viejo H, Teide J2, Lavas Negras, Arenas Blancas, Montaña Rajada and Montaña Reventada) of the basanitic-phonolitic suite of the Teide-Pico Viejo volcanic system (Tenerife, Spain). Comparing analysed feldspar/groundmass pairs with predicted partition coefficients obtained with the models provides a way of distinguishing between feldspars that are in or out of equilibrium with their host melt, and of reconstructing feldspar histories. The results demonstrate the existence of a distinct population of feldspars that had undergone accumulation, fusion and recrystallization events, in Lavas Negras and Arenas Blancas flows. In addition, the anomalous trachytic composition of Montaña Reventada is due to melting of a feldspar- dominated cumulate.

Because of their social, economic and political contexts, and their intrinsic multi-hazard nature, volcanic islands are one of the most vulnerable environments, where natural hazards (volcanic and non-volcanic) tend to occur in a simultaneous way causing cascading effects. To date, most of the scientific knowledge, as well as hazard assessment and risk management protocols focus on individual hazards and risks, while it remains a challenge to correctly predict the outcomes and impacts of a multi-hazard scenario where several hazardous phenomena may interact in simultaneous or consecutive ways. The multi-hazard concept originated in the 1990s in the international political context precisely to respond to this need. After its first appearance, different–and often, contradictory–usage perspectives of the multi-hazard concept have been increasingly put forward, thus making it difficult for this new approach to be fully implemented into disaster reduction policies. The present study assesses the current status of the application of the multi-hazard approach in existing risk management systems, and proposes future improvements to disaster risk reduction. It also presents the multi-hazards to which volcanic islands are exposed and analyses their potential impacts, taking the Canary Islands as a case study. In doing so, it emphasizes the need to establish a cross-sectoral, climate change-oriented, socially-inclusive, multi-risk management system, based on scientific knowledge and linked to critical societal demands and solutions.

Volcanic eruptions are key drivers of climate variability, with complex environmental consequences at regional and local scales that are rarely documented in high-resolution sedimentary records. In this work we present the results of a 15 m long paleolake core (Pla de les Preses core, Vall d’en Bas, Girona, NE Spain) covering the Late Pleistocene-Holocene transition. Multiproxy analyses including chronostratigraphy, sedimentology, micropalaeontology and geochemistry are used to reconstruct the paleoenvironmental framework of the Late Pleistocene-Holocene transition and to detect the youngest Holocene volcanic eruptions in the Garrotxa Volcanic Field (GVF) and the Iberian Peninsula. The studied sedimentary record covers the last ca. 13.5 ka cal BP and was punctuated by several rapid climatic changes including the 9.3, 8.2 and 7.1 ka events, affecting the hydrological evolution of a barrier-lake formed due to the volcanic damming of the Fluvià river. Sedimentological and geochemical analyses unveil the environmental history of Vall d’en Bas valley; the formation of a lacustrine area within a fluvial environment around 13.5 ka cal BP and later a wetland phase between 9.3 and 8.2 ka cal BP. Abrupt sedimentary changes marking the onset and demise of the wetland phase were linked to hemispheric cooling and drying events (e.g. 9.3 and 8.2 ka cal BP), provoking a decline in the water table during these phases. In addition, 30 tephra layers are detected thorough the core, showing previously unknown intense volcanic activity from 13.5 to 8.3 ka cal BP in the GVF. In that sense, the Pla de les Preses sequence provides, for the first time, evidence for early Holocene volcanic activity in NE Iberia that should be taken into account in future tephra studies in the western Mediterranean realm.

Active volcanic islands are particularly vulnerable to multi-risk natural hazards, many of which are anticipated to become more severe as a result of climate change. It is crucial to create and put into action adequate risk mitigation plans based on comprehensive long-term hazard assessments that include nature-based solutions in order to improve societal safety on these islands. Herein, we study the case of Tenerife. After a compilation and analysis of the potential resources of this island, as well as a study of its main natural hazards and how they are currently managed, we have determined that the most viable solutions are nature-based ones. Land management based on prior assessment of the island’s hazards is the key to strengthening Tenerife’s current risk mitigation plans. This will allow for a two-way relationship between the exploitation of sustainable tourism and the education of its population, both oriented toward the conservation of its geological heritage, and will promote the sustainable use of the energy and material resources currently being exploited. This contribution thus establishes the pillars from which to exploit the nature-based solutions offered by Tenerife as the only viable option for its sustainable economic development.

The Garrotxa Volcanic Field (GVF) is one of the monogenetic Quaternary volcanic fields associated with the intraplate European Cenozoic Rift System. The GVF is located between the cities of Olot and Girona, NE Spain, and it covers an area of about 600 km2. This volcanic field ranges in age from 0.7 Ma to early Holocene and is considered active since the last eruption dated 11,000-13,000 years ago. The volcanic activity, mainly controlled by regional normal faults generated during the Neogene extension, was highly variable with over 50 scattered eruptive vents that were produced during short-lived monogenetic eruptions. Scoria cones represent the most common landforms of the GVF with subordinate maars and tuff rings/cones. Most of the volcanoes are located in the northern sector between the towns of Olot and Santa Pau and they stand on a folded Eocene basement. Volcanoes located in southern area of the field, close to the city of Girona, stand mainly on a fractured Paleozoic basement. The objective of this work is to identify eruptive processes and the geomorphic evolution of volcanic edifices and related them to environmental influencing factors. The best volcanic structures in the GVF have been selected due to their well-preserved morphologies. Cones (Wco) and craters (Wcr) mean diameters, as well as cones maximum height (Hmax), maximum crater depth (Dcrmax) and external slope of the cones (Smedian) have been measured. This study shows that it is possible to create a catalogue of likely eruption sequences based on field evidences and morphological/morphometric data. In this way, a more realistic eruption scenarios can be developed for different parts of the volcanic field. Morphometry can also provide rough relative age constraints on edifices. These methodologies can improve our understanding for a better evaluation of volcanic hazards in urbanized volcanic fields as the GVF.

During monogenetic eruptions, external controlling parameters such as fracturing patterns, differences in the hydraulic properties and heterogeneities of the basement rocks play an important role in creating small edifices. This is reflected by changes in eruptive styles, deposits as well as the morphology of the volcanic cones. The deposits of the Puig de la Banya del Boc (PBB), a monogenetic volcanic cone located in the Garrotxa Volcanic Field (GVF) are a good example of the complex basement-influenced eruptive behaviour. The aim of this study is to determine the eruptive history and dynamics of the PBB volcano, by means of sedimentological, stratigraphic and lithostratigraphic analyses of its deposits. The PBB cone, located on a hard basement of Palaeozoic metamorphic rocks, was built during a single eruption and it shows a complex eruptive succession with phreatomagmatic, Strombolian, and effusive phases. The succession of deposits of the PBB reveals the influence of the substrate, upon which the volcano forms, in this case the crystalline Paleozoic basement, and its hydrodynamic properties that controlled the way in which magma/water interactions occurred throughout the eruption This work represents a further step towards improving the understanding of magma-water interaction in complex environments as the GVF.

The behaviour of Group I and II elements during the petrogenesis of felsic igneous rocks is largely controlled by feldspar-liquid relationships. Numerous experimental studies have addressed plagioclase/melt element partitioning, with fewer studies devoted to potassium feldspar, and very few to albite-rich ternary-composition feldspar (An ∼ Or < Ab). However, the partition coefficient for Ba is known to increase by at least an order of magnitude through the crystallisation sequence sodic plagioclase–anorthoclase–potassium feldspar that is typical of sodic alkaline suites. Feldspars, glasses, and whole rocks in such suites may exhibit strong enrichments and depletions that can be used to track processes of crystal fractionation, cumulate formation, and cumulate recycling. Here, we review experimental feldspar/melt partitioning data for Ba, Sr, and Rb for all feldspars. Regression of available data provides expressions that appear to adequately model the compositional and temperature dependence of partition coefficients for albite-rich compositions. We have applied this model to feldspar and melt compositions of the products of several Holocene eruptions (Pico Viejo C, Pico Viejo H, Teide J2, Lavas Negras, Arenas Blancas, Montaña Rajada and Montaña Reventada) of the basanitic-phonolitic suite of the Teide-Pico Viejo volcanic system (Tenerife, Spain), using EPMA and LA-ICP-MS analyses. Comparing analysed feldspar/groundmass pairs with predicted partition coefficients obtained with the models provides a way of distinguishing between feldspars that are in or out of equilibrium with their host melt, and of reconstructing feldspar histories. The results demonstrate the existence of a distinct population of feldspars that had undergone accumulation, fusion and recrystallisation events, in Lavas Negras and Arenas Blancas flows. In addition, the anomalous trachytic composition of Montaña Reventada is due to melting of a feldspar-dominated cumulate. Application of these techniq

The characterisation of the past behavior of a volcanic system (e.g. eruption magnitude, recurrence, location, etc.) is a necessary first step in volcanic hazard assessment and evaluation of related uncertainties of future events. These records are obtained in different ways: field-based geological studies, in case of ancient and preserved deposits, historical observations, for more recent events, or multi parametric geophysical monitoring, which provides in situ eruption information. The multiplicity of data sources yields to heterogeneous information from the past, not only in the number of the events and their characteristics but also in the completeness of records across the timeline. Additionally, the reconstruction of past events based on the actual ranking of explosivity, becomes challenging in volcanoes considered effusive. The current classification of the eruptions links volumes and column height in a proportional-incremental relation, which means, if volume increases, the column height escalates as well. Additionally, the size of the plume height could be linked to more than one classification, diffusing the clear frontier between effusive- dominated or explosive-dominated events. The Canary Islands volcanoes are examples of environments where the big volumes of ejected material are not always associated with big ash plumes. A study based on the eruption energy balance and partition and the use of volcano analogues to complement record gaps can provide an alternative approach in volcanic settings displaying combined effusive and explosive events. The energy balance and partition can be converted into energy-based Probability Density Functions (EPDFs). Likewise, the EPDFs are capable of being fragmented into energy released by different volcano products. In the case of volcanoes with limited historical record, such as Canary Islands (Tenerife, La Palma, El Hierro, Lanzarote), the EPDF of one or many analogue volcanoes can be used and adjusted to describe t

Graben calderas are volcano-tectonic structures that use the faults of a graben as main vents from which magma is massively erupted from a shallow magma chamber during collapse of intra-graben blocks. These eruptions are generally silicic and explosive and form large volume ignimbrite sheets without a previous Plinian major depressurization event. Graben calderas can be associated to tectonic settings ranging from pure extension to strike slip ranstension, including complete grabens, half-grabens or pull-apart grabens. The Sierra Madre Occidental (SMO) in western Mexico includes several of these graben type calderas with the corresponding large volume ignimbrite sheets that result from fissure type eruptions along the graben’s border and interior faults. The Bolaños graben constitutes one of the best examples of these tectonically controlled collapse calderas and is the second largest caldera of the world after Toba caldera. It is a 90 x 25 km rectangular caldera and the vent of the 25.37 ± 0.36 Ma silicic Alacrán ignimbrite, with a minimum Dense Rock Equivalent volume of 2,650 km3 (3,800 km3 rock volume). Post-collapse silicic domes were emplaced just after the Alacrán ignimbrite from 25.02 ± 0.33 Ma to 23.94 ± 0.33 Ma, with a total minimum lava volume of 171 km3. Both ignimbrite and domes account for at least 2,800 km3 rhyolitic magma output from Bolaños graben caldera, without considering the distal deposits, and in particular the co-ignimbrite ash-cloud deposit. We describe the characteristics of the Bolaños graben caldera focusing on its major products, the Alacrán ignimbrite and the post-collapse dome volcanism, providing the geological frame of the Bolaños graben area documented with 40Ar-39Ar ages. We finally propose a conceptual model to explain the dynamics of the Bolaños graben that can be applied to other similar volcano-tectonic depressions of the Sierra Madre Occidental and elsewhere in the world with similar geological settings.

Simulating lava flows on a gentle slope is complex since they can propagate in a wide range of directions. It is an even greater challenge to define lava flow trajectories when an eruption lasts over several years and flows cool down, changing the surrounding topography. In this study, we test Q-LavHA, an open source plug-in that simulates lava flow inundation calculating its probability, and using Paricutin’s eruption (1943–1952) in central Mexico as a case study. We have appropriately calibrated the Q-LavHA plug-in for the Paricutin case study, which provides insights on how to better model lava flows in gentle terrain. From this work, we observe that each phase is characterized by a unique set of parameters requiring a careful calibration and that low-relief topographies require special consideration. Our findings could be useful for real-time hazard evaluation in future volcanic scenarios in the Michoacán–Guanajuato volcanic field and elsewhere, where new monogenetic eruptions similar to Paricutin can be expected.

The original version of this Article contained a repeated error in the Introduction, in Figure 1 and its accompanying legend, in the Results section under the subheading ‘Stress changes caused by the earthquakes’, in the Discussion and conclusions section under the subheading ‘Volcanic eruptions long after the earthquakes’, and in the Supplementary Information file, where the earthquake that occurred on November 7, 2012 was incorrectly mentioned as having occurred on November 11, 2012. The original Fig. 1 and accompanying legend appear below. The original Article and the Supplementary Information file that accompanies the original Article have been corrected.

In this work, we present new Bouguer and residual Bouguer anomaly maps of the Central Pyrenees calculated from 3590 stations, of which 1141 are new observations acquired from surveys performed between 2018 and 2019. The most prominent feature of the Bouguer anomaly is the long wavelength elongated minimum in its central part that continues to the W and ends towards the E with a positive gradient that seems to envelope the minimum. Other short and medium wavelength minima are superimposed, some placed over the batholithic outcrops. In the residual Bouguer, the main relative minima are related with outcrops of batholiths or interpreted buried granites except for the prominent minimum South of La Maladeta Granite, associated with Triassic evaporitic accumulations. These maps (shown on the Main Map) will help characterizing the Permo-Carboniferous batholiths of the Central Pyrenees, in particular La Maladeta and Andorra Mont-Louis granites in order to add constraints to the mechanism of their emplacement.

A new gravity survey (1164 gravity stations and 180 samples for density analysis) combined with two new geological cross sections has been carried out in a sector of the Central Pyrenees in order to improve the characterization of basement and cover architecture. From North to South, the study area comprises the southern half of the Axial Zone and the northernmost part of the South-Pyrenean Zone. New gravity data were combined with previous existing databases to obtain the Bouguer and residual anomaly maps of the study area. The two cross sections, oriented NNE–SSW, were built from field data and previous surficial and subsurface data and cross the La Maladeta plutonic complex. The residual anomaly map shows values ranging from −18 to 16 mGal and anomalies mainly oriented N120E. The two 2.5D modelled cross sections show similar observed gravity curves coinciding with similar interpreted structural architecture. Data show a gravity high oriented N120E coinciding with the Orri basement thrust sheet and an important gravity depression, with the same orientation, coinciding with the leading edge at depth of the Rialp basement thrust sheet and interpreted as linked to a large subsurface accumulation of Triassic evaporites. The volume at depth of the La Maladeta and Arties granites has been constrained through gravity modelling. This work highlights that the combination of structural geology and gravity modelling can help to determine the structural architecture of an orogen and localize accumulations of evaporites at depth.

Understanding the relationship cause/effect between tectonic earthquakes and volcanic eruptions is a striking topic in Earth Sciences. Volcanoes erupt with variable reaction times as a consequence of the impact of seismic waves (i.e. dynamic stress) and changes in the stress field (i.e. static stress).In2012, three large(Mw≥7.3)subductionearthquakes struck Central Americawithin a period of 10 weeks;subsequently, some volcanoesin the regionerupted a few days after, whileotherstook months or even years to erupt. Here, we show thatthese threeearthquakes contributed to the increase in the number of volcanic eruptionsduring the 7 years that followed these seismic events. We found that onlythosevolcanoes that were already in a critical state ofunrest eventually erupted, which indicates that the earthquakes only prompted the eruptions. Therefore, we recommend the permanent monitoring of active volcanoes toreveal which are more susceptible to culminate into eruption in the aftermath of the next large-magnitude earthquake hits a region.

The dimensions, the geographical position and the complex geological history of the Iberian Peninsula makes it a unique and singular target to study its crustal and upper mantle structure and geodynamical evolution using geophysical methods. The lithospheric structure beneath Iberia has been investigated since the 1970’s using deep multichannel seismic reflection and refraction/wide-angle reflection profiling. Gravimetric and magnetic data were acquired following the deployment of permanent and temporary stations, mostly during the 1990’s. Beginning in the late 1990’s, the progressive use of Global Navigation Satellite Systems (GNSS) instruments contributed to monitor the present-day motions. During the last decades, numerous geological and geophysical surveys have investigated the Iberian lithosphere and upper mantle in the onshore and offshore regions, the most recent ones related to the TopoIberia project. The approach developed in this contribution is twofold. Firstly, we summarize the available geophysical information over Iberia, from focusing on the upper crust to the lithosphere-asthenosphere boundary and the transition zone marking the bottom of the upper mantle. Results of GNSS data, potential fields, controlled source seismic profiles, magnetotelluric data, body and surface wave tomography, receiver functions and 2D and 3D lithospheric modeling are reviewed and compared. Secondly, we focus on the areas of greater geodynamic interest and the regions where inconsistencies within the geophysical results, or contradictions in their tectonic interpretation exist, identifying the major questions that are still under debate. Besides shedding light to the state of knowledge and pointing out present-day research challenges, this review provides a tool for the integration of the diverse geophysical datasets with the surface geology and geodynamical processes that are interpreted to have built the complex geology of the Iberian Peninsula.

Extreme geohazards (volcanic eruptions, earthquakes, landslides, and tsunamis) have the potential to inflict cascading effects whose associated risks are difficult to predict and prepare for. Thus, these events are generally not taken into account in hazard assessment. Anticipating the occurrence of such extreme events is thus key if our life-styles are to remain safe and sustainable. Volcanic islands are often the source of complex successions of disastrous events, as is evident from any examination, for instance, of the geological record of regions such as Hawaii, the Canary Islands, Reunion and Indonesia. The island of Tenerife in the Canary Archipelago is an excellent example of where cascading extreme hazards have occurred several times in the past and could occur again in the future. A cascading sequence involving a caldera-forming eruption, high-magnitude seismicity, mega-landslides and tsunamis occurred at least twice during the construction of this island. In order to understand the possible consequences of such processes if they were to reoccur, we simulated the extent and potential impact of a multiple, extreme geohazard episode similar to the last recorded one that took place on the island of Tenerife around 180 ka. The implications of such a disastrous succession of events are analyzed at local, regional and global scales, and the results obtained are discussed within the framework of disaster risk-reduction policies.

Camp dels Ninots is a mixed hard-soft maar-diatreme located in the Catalan Volcanic Zone (NE of Iberia), in which intra-maar lake sediments have preserved one of the most remarkable Pliocene fossil records in Europe. Geophysical surveys combined with the geological map and 11 boreholes, including two new continuous intra-crater drill cores, have enabled the construction of a 3D geological model of this maar-diatreme and its basement. The formation of this maar-diatreme started with a vent-opening phreatomagmatic explosion at the intersection between a regional fault and the Paleozoic groundwater level at a depth of 210 m. We infer and calculate the geometry, dip direction and dip angle of this regional fault. During the eruption, mixed Strombolian and phreatomagmatic episodes occurred, forming the tuff ring and filling the diatreme with minimum estimated volumes of 0.012 and 0.004 km3, respectively. The diatreme infill is composed of three main lithofacies that include tuff-breccias, welded scoriae, and mafic intrusions into the phreatomagmatic breccias. Thus, the stratigraphy of the diatreme succession suggests a progression of explosive events from deeper to shallower zones with short lateral migration of explosion vents, which control its final morphology, without evidence for significant deep enlargement of the diatreme during the later phases. This generated a wide funnel-shaped with low diatreme wall angles that differs from kimberlite pipes with great depths and sharp slope geometries. Hence, such 3D geological model helps to understand the complex architecture of maar-diatreme structures, highlighting the lack of geological modeling of this type of monogenetic system.

The Paleocene-Eocene Cerro Munro pluton, to the east of the North Patagonian Batholith (NPB), is a tonalitic intrusion emplaced as a shallow, small, sub-circular tonalite-granodiorite body hosting abundant co-magmatic mafic microgranular enclaves (MME). Besides, the intrusive body is crosscut by radial porphyritic dikes and has been related to andesitic, dacitic and rhyolitic dikes, lava flows and ignimbrites cropping out at neighboring areas. Magmatic contacts between MME and host tonalites, together with their common geochemical features, suggest derivation from a common parental magma, although short-range mineralogical and geochemical differences point to an early crystallization of MME (chilled margins) at the sidewalls of ascent conduits or at shallow reservoirs. The established thermal gradient and the advance of the solidification front were responsible for the presence of the mafic microgranular and tonalitic subsystems and, in a continuous process, promoted the water saturation and the second boiling that finally account for the segregation of a water rich highly differentiated residual liquid. Hbl-Pl cumulate textures observed in the tonalites and mafic enclaves, as well as incompatible element-enriched rhyolitic melts record the results of this in-situ differentiation process. Usingle bondPb zircon ages obtained from tonalites (57.1 ± 1.4 Ma), dacitic (55.4 ± 0.6 Ma) and rhyolitic (54.1 ± 0.7 Ma) dikes constrain an age of around 54 Ma for the final consolidation of the tonalitic magma and the crystallization of the expelled highly differentiated melts. This age coincides with the deposition of dacitic volcanic and volcanoclastic deposits to the north of the Cerro Munro pluton, which suggests that the fractionation process led to the extrusion of segregated melts, favored by extension, uplift and exhumation of an active rift tectonic setting.

Volcanic zones are important geoheritage sites. Active volcanic fields are of special interest because they allow to observe the complex and interesting stratigraphic relationships that often characterise their products and processes, as well as landscapes of unusual beauty. These geological sites enable visitors to appreciate the full complexity of volcanic activity and the importance of the geoheritage values that should be preserved. To ensure a correct preservation of these zones while opening them up to visitors, management plans should establish and consolidate a network of outcrops that allow visitors to get to know the area in question and preserve its geological heritage and the social and economic dynamism. In La Garrotxa Volcanic Field, most of which is protected by a natural park, a new methodology has been created to identify the sites of greatest geological interest and, above all, those that exemplify the diversity of eruptive styles and volcanic products and landforms in the area. Taking into account the most relevant management requirements (conservation and dissemination), in 1994 a total of 60 outcrops were classified as points of geological interest of the area. In this study we further present a specific methodology to select the most suitable sites for the preservation of the main volcanological features of La Garrotxa Volcanic Field. A group of 12 sites were selected from the initially identified outcrops and included in an itinerary as the most representative geological and pedagogical sites while also bearing in mind their ease of access and preservation and the possible impact of visitors (e.g. erosion). The following five criteria were considered when restoring these outcrops: integration into the landscape, consolidation of their geology, regulation of visits, the mitigation of risk, and the participation of the people that live in the area.

We present a detailed stratigraphy of the Coranzulí caldera-forming deposits. This caldera, located in the Altiplano-Puna Volcanic Complex (Central Andes), generated four ignimbrite deposits with similar field characteristics and facies that differ from each other in, above all, the nature of the lithic fragments they contain. Three different lithofacies (fine-grained cross-stratified facies, massive lithic breccia facies and massive ignimbrite facies) are found in all the ignimbrite deposits, which occasionally also contain a lenticular lithic-rich facies and/or a pumice-rich facies. These field characteristics and, in particular, local deposit thicknesses were used to develop a theoretical model of the dynamics and emplacement mode of the Coranzulí pyroclastic flows. Our results show that these ignimbrites were emplaced by dense pyroclastic density currents subjected to high accumulation rates and velocities, thereby indicating rapid en masse emplacement that was also influenced by local paleotopography as deduced from facies analysis.

Anticipating volcanic eruptions at central volcanoes require knowing how magma chambers prepare for new eruptions. Pre-eruptive processes that occur in such magma chambers are recorded in the products of these eruptions, so their characterisation in terms of magma composition and physics offers the clues to understand past eruptions and predict future ones. Here, we study the very well preserved pyroclastic succession of El Palomar Member (712 ± 41 ka), in Las Cañadas caldera, Teide, Canary Islands. This deposit resulted from a single explosive eruption of a phonolitic magma that started with a sustained eruption column (sub-plinian or plinian) that formed a massive, 40 m thick non-welded fallout deposit, progressively changing into a lower intensity fire fountain that deposited a 25 m thick fallout succession of non-welded to strongly welded pumices. Stratigraphic and petrological data suggest that this eruption was related to a thermally-compositionally zoned and relatively shallow magma chamber in which the arrival of a hotter and more mafic magma rapidly triggered the eruption. The studied deposit shows how this zoned structure was maintained during the whole process, which allows one to reconstruct what happened during the eruption. Comparison of this eruption with the current situation at Teide volcano alerts on the potential rapid preparation for new eruptions in the case that sufficient phonolitic magma was available in the shallow plumbing system of this active volcano if new inputs of deeper magma take place.

San Miguel volcano (or Chaparrastique), one of El Salvador's most active volcanoes, has erupted 28 times in the past 431 years (historical period). The majority of historical eruptions have been Strombolian (VEI 1–2) that have occurred from the central vent and have generated ashfall and ballistics, but some of them (8) have been effusive flank eruptions, mainly producing lava flows of basaltic and basaltic-andesite composition. Secondary lahars generated by remobilization of the young tephra are also common at San Miguel volcano. Using the information for these historical as well as prehistoric eruptions and applying probabilistic tools designed for volcanic-hazards assessment, we simulated: (1) the five most likely scenarios (ashfall scenarios, local-moderate extent, and VEI 1–2); (2) other probable scenarios related to lava flows, based on the historical record of the volcano; (3) other possible scenarios related to pyroclastic density currents (PDCs) with similar characteristics to those that occurred during its eruptive history; and (4) the most hazardous scenarios (ashfall, lava flow, PDC) that have been identified from its prehistoric geological record. Finally, we construct a qualitative integrated volcanic hazard map through the combination of the simulated scenarios. This study was developed with the aim of improving the existing volcanic-emergency plan. It should serve to improve the collaboration and coordination between scientists, the national observatory (OA-MARN), and the civil protection agency of San Miguel municipality, and will help to strength this cooperation to respond effectively to future volcanic crises.

The Angolan alkaline–carbonatite complex of Monte Verde has a semi-circular shape and is comprised of a central intrusion of foidolite rocks surrounded by concentrically arranged minor bodies of other alkaline rocks and carbonatite magmatic breccias. This rock association is hosted by fenitized Eburnean granites. Concentric swarms of alkaline dykes of late formation, mostly of nepheline trachyte composition, crosscut the previous units. Most high-field strength elements (HFSE) and rare earth elements (REE) are concentrated in pyrochlore crystals in the carbonatite and alkaline breccias. Magmatic fluornatropyrochlore is replaced and overgrown by five secondary generations of pyrochlore formed during subsolidus stages and have higher Th, REE, Si, U, Sr, Ba, Zr, and Ti contents. The second, third, and fourth pyrochlore generations are associated with late fluids also producing quartz and REE rich minerals; whereas fifth and sixth pyrochlore generations are linked to the fenitization process. On the other hand, minerals of the rinkite, rosenbuschite, wöhlerite, eudialyte groups, as well as loparite-(Ce), occur in accessory amounts in nepheline trachyte, recording low to moderate agpaicity. In addition, minor REE-bearing carbonates, silicates, and phosphates crystallize as late minor secondary minerals into carbonatite breccia and alkaline dykes. In conclusion, the scarcity of HFSE and REE minerals at the Monte Verde carbonatite-alkaline-agpaitic complex suggests low metallogenetic interest and economic potential for the outcrops analysed in this study. However, the potential for buried resources should not be neglected.

Most volcanoes on the Earth rise from the bottom of seas and oceans. Most of them do not reach the surface of sea and remain hidden to all conventional observations from surface and space. Only some of them rise above the sea level, forming islands and passing from submarine to subaerial volcanism. Volcanic islands develop in virtually all the geodynamic contexts on Earth, from mid-ocean ridges (Iceland), to intraplate (Hawaii), to volcanic arcs (Aeolian Islands). All the liquid-descent evolutive degrees of magma are finally represented, from primitive compositions up to strongly evolved rhyolite, trachyte and phonolite lavas. So, the eruptive styles of these volcanoes range consequently from mild effusions to plinian eruptions.

Accurately dating phenocrysts in Holocene volcanic rocks poses many challenges but is critical to placing magmatic processes that occur prior to eruption into a temporal frame-work. We dated alkali feldspar (i.e., orthoclase Or10 to Or46) crystals in four young phonolites from the Teide–Pico Viejo volcanic complex, Tenerife (Spain), using (226Ra)/(230Th) isotopes. Partition coefficients of Ra (DRa) and DRa/DBa of feldspars were predicted using an approach based on the lattice strain model, which yielded crystallization ages that overlap or predate known eruption ages for the Lavas Negras (ca. 1 ka), Montaña Blanca (ca. 2 ka), Arenas Blancas (ca. 2–4 ka), and Teide H (ca. 6 ka) phonolites. Crystallization of feldspar may occur up to the time of eruption, with >8 ka crystals also present, possibly suggesting extended magma differentiation times. However, feldspars yielding finite (226Ra)/(230Th) ages are mostly in equilibrium with the groundmass, unlike >8 ka crystals, which were therefore identified as antecrysts/xenocrysts. The 87Sr/86Sr ratios of feldspars indicate that crystallization predated late-stage assimilation, affecting 87Sr/86Sr ratios of some melts. The (226Ra)/(230Th) ages also constrain the tempo of phonolite magma evolution on Tenerife. Integration of (226Ra)/(230Th) ages with feldspar major elements, trace elements, and isotopes provides a powerful means for investigating crystallization histories using a dominant mineral that controls the overall magmatic evolution of phonolites on thousand-year time scales.

Long-term hazard assessment is an essential action that should be undertaken at all active volcanoes and/or volcanic areas as an indispensable contribution to reduce volcanic risk. It allows anticipating new eruptions responding to two of the main questions of volcano forecasting: where and how the next eruption will be. In the case of the Canary Islands, an active volcanic region that receives millions of visitors every year, and which has been recently severely impacted by a small size eruption on the island of La Palma in 2021, a systematic long-term hazard assessment is still pending, despite this being foreseen in its management plan to face volcanic threats. An essential basic long-term volcanic hazard assessment, conducted six years before this last eruption, was able to anticipate the location of the new vents and the eruptive style, including the extent of its main potential hazards. This long-term research was developed in the frame of a Master thesis, which was aimed at justifying the viability of a particular systematic long-term volcanic assessment methodology to be applied to the Canary Islands and elsewhere. Despite this particular study was not used to manage the La Palma 2021 eruption, it demonstrates how beneficial such studies may be to forecast new eruptions and to reduce their associated risk, and represents a new contribution to develop adequate territorial and management planning where we provide a qualitative hazard map for the Island of La Palma.

The physical processes that operate within, and beneath, a volcano control the frequency, duration, location and size of volcanic eruptions. Volcanotectonics focuses on such processes, combining techniques, data, and ideas from structural geology, tectonics, volcano deformation, physical volcanology, seismology, petrology, rock and fracture mechanics and classical physics. A central aim of volcanotectonics is to provide sufficient understanding of the internal processes in volcanoes so that, when combined with monitoring data, reliable forecasting of eruptions, vertical (caldera) and lateral (landslide) collapses and related events becomes possible. To gain such an understanding requires knowledge of the material properties of the magma and the crustal rocks, as well as the associated stress fields, and their evolution. The local stress field depends on the properties of the layers that constitute the volcano and, in particular, the geometric development of its shallow magma chamber. During this decade an increasing use of data from InSAR, pixel offset and structure-from-motion, as well as dense, portable seismic networks will provide further details on the mechanisms of volcanic unrest, magma-chamber rupture, the propagation of magma-filled fractures (dikes, inclined sheets and sills) and lateral and vertical collapse. Additionally, more use will be made of accurate quantitative data from fossil and active volcanoes, combined with realistic numerical, analytical and machine-learning studies, so as to provide reliable models on volcano behaviour and eruption forecasting.

The immense advances in computer power achieved in the last decades have had a significant impact in Earth science, providing valuable research outputs that allow the simulation of complex natural processes and systems, and generating improved forecasts. The development and implementation of innovative geoscientific software is currently evolving towards a sustainable and efficient development by integrating models of different aspects of the Earth system. This will set the foundation for a future digital twin of the Earth. The codification and update of this software require great effort from research groups and therefore, it needs to be preserved for its reuse by future generations of geoscientists. Here, we report on Geo-Soft-CoRe, a Geoscientific Software & Code Repository, hosted at the archive DIGITAL.CSIC. This is an open source, multidisciplinary and multiscale collection of software and code developed to analyze different aspects of the Earth system, encompassing tools to: 1) analyze climate variability; 2) assess hazards, and 3) characterize the structure and dynamics of the solid Earth. Due to the broad range of applications of these software packages, this collection is useful not only for basic research in Earth science, but also for applied research and educational purposes, reducing the gap between the geosciences and the society. By providing each software and code with a permanent identifier (DOI), we ensure its self-sustainability and accomplish the FAIR (Findable, Accessible, Interoperable and Reusable) principles. Therefore, we aim for a more transparent science, transferring knowledge in an easier way to the geoscience community, and encouraging an integrated use of computational infrastructure. Systematic Review Registration: https://digital.csic.es/handle/10261/193580