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Avocado production has boomed worldwide in recent years, and Spain, including the Canary Islands, has been no exception. The number of avocado growers in the region has increased significantly as growers recognize the potential of this crop. However, several species of spider mites (Tetranychidae) pose a risk to this crop, with the genus Oligonychus being the most diverse and having the greatest economic impact. In particular, Oligonychus perseae (Tuttle, Baker and Abbatiello) has been reported as the one mainly responsible for the economic damage in major avocado-producing regions worldwide. In this paper, we aim to present an overview of the studies conducted and the measures implemented to mitigate the impact of O. perseae after its arrival in the Canary Islands. Our objective is to provide a detailed description of the current status of this pest (O. perseae), with special attention to its situation 17 years after its first appearance in avocado crops in the Canary Islands. In doing so, we aim to provide valuable insights and knowledge to understand and manage better the challenges posed by O. perseae in this region. [ABSTRACT FROM AUTHOR]

The location, size, and structure of the farmlands and hydraulic systems built by the Indigenous inhabitants of Gran Canaria, Canary Islands, Spain, remain unknown. This hampers our ability to understand how they organized agricultural production and how European settlers transformed local landscapes to build commercial plantations in the late fifteenth century. This paper combines an analysis of archival sources with the study of agricultural landscapes and practices to identify and describe the fields that were employed by the first colonists of Agüimes and Temisas, and to derive information about the location, design, and management of the pre-Hispanic farmlands. [ABSTRACT FROM AUTHOR]

This paper analyzes different forms of violence identified among the ancient Canarians, a population that settled an oceanic island and remained there, without regular external contacts, for more than a millennium. Specifically, we focus on a funerary deposit composed of 14 individuals with high rates of violence, in some cases of a lethal nature. The study uses forensic anthropology techniques to characterize the individuals' injuries. It also explores the chrono-cultural framework in which they were inserted for an historical explanation. The high frequency of individuals with evidence of violence, the features of traumatic injuries, and the radiocarbon data suggest an event of extreme physical violence. This episode appears to be linked to socioeconomic changes, including population growth, marked social differences, rivalry between groups, and competition for control of the resources in a small and diverse territory. The different patterns of violence identified among the skeletal remains in Gran Canaria serve to explore the nature of human relations over a prolonged period in an insular context. [ABSTRACT FROM AUTHOR]

The aim of this study is to assess the importance of geotourism before, during and after the eruption of the Tajogaite Volcano (September to December 2021) on La Palma, Spain. The methodology applied consisted of identifying the geotourism products on the island before the eruption, the importance of the volcano for geotourism – by means of a survey – and the geotourism products developed after the eruption. The findings show that, before the eruption, La Palma's tourism products (hiking, archaeology, stargazing and volcano tourism) were closely related to its volcanic heritage. During the eruption, Tajogaite became a tourist attraction for the island, drawing thousands of visitors and scientists. Lastly, now that the eruption has ended, geotourism is playing a key role in the various island recovery plans through the evaluation of sites of geotourism interest and the design of geotrails in natural and urban areas. [ABSTRACT FROM AUTHOR]

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Wastewater treatment plants (WWTPs) have been identified as significant point sources of microlitter particles (MPs) released into the environment. Simultaneously, they play a crucial role in effectively removing a substantial amount of MPs originated from domestic and industrial activities. This study evaluates the presence and chemical composition of MPs within the range of 5 mm to 25 µm in effluents from three WWTPs in the Canary Islands, each undergoing distinct treatment processes: pretreatment (PRET), activated sludge (AS), and membrane bioreactor (MBR) over an eight-month period. The concentrations of MPs exhibited substantial variations in the three effluent samples: 7461.50 ± 3843.87 MP/L in PRET, 32.71 ± 19.55 MP/L in AS, and 9.53 ± 5.21 MP/L in MBR. The predominant forms of MPs were fragments (58–66%) and fibers (27–33%), with the most prevalent size class being within the range of 150–25 µm. The mass concentrations of plastics, analyzed through pyrolysis gas chromatography–mass spectrometry (Pyr-GC/MS), were determined as 123.33 µg/L for PRET, 17 µg/L for AS, and 10 µg/L for MBR. This study revealed a diverse polymer profile, with polyvinyl chloride (PVC) and polyolefins (PE and PP) predominantly present. This work enhances our understanding of MP dynamics and provides a valuable reference for future assessments, aiding in the selection of effective removal technologies. [ABSTRACT FROM AUTHOR]

Subsidizing residents on airlines is a common policy in a number of countries. However, the question arises as to how changes in this policy affect the travel behavior of residents in specific regions? To address this, we analyze the effect of an "exogenous shock" (i.e., an increase in the resident subsidy) on two Spanish archipelagos when they travel away from the islands. Our Difference-in-Difference and matching estimations find that the causal impact of the policy change is different for resident passengers across the two regions affected. Although the length of stay was reduced for resident passengers in both archipelagos by 10%–15% after the shock, their expenditure at destination per day increased by 13% on the Balearic Islands, while showing no significant change on the Canary Islands. J.E.L. Codes: L83; H25; L93 [ABSTRACT FROM AUTHOR]

The aim of this study is to evaluate the geomagnetically induced current (GIC) hazard in the power networks of the Canary and Balearic archipelagos. This is done in order to strictly complete the detailed assessment at national level of the power transmission system of mainland Spain, including the 400 and 220 kV levels. We have constructed models for the grids in each of the individual systems and used resistivity models of the lithosphere for each group of islands, from which we have calculated the surface impedances. The respective models of electrical admittances of the grids have been combined with the geoelectric field derived from the convolution of the recorded (or expected in an extreme scenario) geomagnetic storms and the impedances calculated from the geoelectrical models to derive the expected GICs in the power lines, substations, and transformers. The low geomagnetic latitude of the Canary Islands combined with the small size of their power networks, makes them one of the least likely electrified locations to record significant GICs, with less than 3 A for the 100‐year return period. Even the 13 A that could be reached for the upper limit of the 95% confidence interval at the 500‐year return period does not seem likely to have a significant impact. The Balearic Islands, being at higher latitude and with a system length of approximately 300 km, including alternating current power lines connecting the Islands, shows GIC signals of moderate amplitude with up to 40 A for the 100‐year return period. Plain Language Summary: In the same way that phenomena derived from meteorological processes can have devastating effects, the Sun emits massive amounts of particles and energy into space that affect Earth technological systems. The related science is analogically called space weather. When the Sun is active, it sends out more charged particles that can affect the regions around the Earth where those particles interact with the planet's magnetic field. This leads to a significant increase of electric currents in these media giving rise to geomagnetic storms. This generated electrical fields act like a voltage source and cause electrical currents to flow through the power networks, that can damage the transformers where the circuit is grounded. Many countries, such as Spain, have undertaken studies to assess the vulnerability of their power grids to the danger posed by this phenomenon, but one question that remained open was whether the grids that transmit power across their islands deserve attention. Our results show that the vulnerability of the Canary Islands is very low, while that of the Balearic Islands is not negligible. Key Points: We quantify the historical geomagnetically induced currents (GICs) and the worst‐case scenarios in the power grids of the Spanish IslandsCanary Islands is one of the least likely electrified locations in the world to record significant GICsThe Balearic Islands, with their higher latitude and long power lines connecting the islands between them, are more vulnerable to GIC [ABSTRACT FROM AUTHOR]

The explosive activity of the 2021 Tajogaite eruption eludes pigeonholing into well‐defined eruption styles, with a variety of pyroclast ejection modes occurring both alternately and simultaneously at multiple vents. Visually, we defined four endmembers of explosive activity, referred to as fountaining, spattering, ash‐poor jets and ash‐rich jets. To capture the physical parameters of these activities, we deployed a camera array including one high‐speed camera and three high‐definition cameras in two field campaigns. Transitions between and fluctuations within activity occurred at the time scale of minutes to hours, likely driven by the same shallow conduit and vent processes controlling Strombolian activity at other volcanoes, but at higher gas and magma fluxes. From a physical standpoint, mean pyroclast rise velocity ranged 5–50 m/s, maximum ejection velocity 10–220 m/s, and sub‐second mass flux of lapilli to bomb‐sized pyroclasts at the vent 0.2–200 × 103 kg/s. The largest mass flux occurred during fountaining, which contributed by far more than other activities to cone building. All explosive activity exhibited well‐defined pyroclast ejection pulses, and we found a positive correlation between the occurrence rate of ejection pulses and maximum pyroclast ejection velocity. Despite orders of magnitude variations, physical parameters shift gradually with no boundary from one activity endmember to another. As such, attributing this explosive activity specifically to any currently defined style variations is arbitrary and potentially misleading. The highly variable explosive activity of the Tajogaite eruption recalls previous definitions of violent Strombolian eruptions, an eruption style whose pyroclast ejection dynamics, however, were so far largely undefined. Plain Language Summary: The 2021 Tajogaite volcanic eruption offered a rare opportunity to study in detail the physical properties and the controlling factors of explosive activity driven by basaltic magmas. The activity lasted almost uninterrupted for almost 3 months and had visually different manifestations occurring simultaneously and alternating at different volcanic vents. To study the explosive activity, we used one high‐speed camera, taking short, slow motion videos, and three commercial grade high‐definition camcorders recording for many hours. We found that the activity changed in features and intensity at the time scale of minutes to hours, largely controlled by changes in the size and debris cover of the vent, magma viscosity, and magma flux and gas content. The ejection velocity of large volcanic particles ranged 5–220 m/s, with mean values around 10–50 m/s. The mass flux of particles erupted reached peaks of 200 metric tons per second. Particle ejection was never steady but always proceeded in pulses, which were more frequent if the ejection velocity was higher. Our measurements show that the current classification schemes for explosive eruptions of basaltic magmas do not adequately describe the activity of the Tajogaite eruption, which represents a type of eruption that was not yet measured in detail. Key Points: High‐definition and high‐speed imaging record the velocity, size, and mass flux of pyroclastsActivity shifted in location, nature and vigor at the time scale of hours and progressed in ejection pulses at the time scale of secondsPhysical parameters of explosive activity vary gradually between apparently different activity styles, without any clear boundary [ABSTRACT FROM AUTHOR]

The recent eruption of the Cumbre Vieja Volcanic Ridge in La Palma started on September 19, 2021, after a series of seismic swarms and lasted 85 days. Seismic swarms showed a large variability but could be grouped in two categories: long-term swarms located at subcrustal depth, showing b-values close to 2.2 and low rates (from 4.1 to 56 events/hour) and short-term swarms located at very shallow depths, showing moderate b-values [0.9, 1.6] and high rates (from 58 to 460 events/hour). Magma ascent velocity within the 0–10 km depth range varied between 0.03 and 0.21 km/h. Spatial and temporal characterization of the b-values for the entire magmatic process during the selected study period also indicated three distinct dynamics during a preparation phase starting from at least October 2017–August 2021, the eruptive phase from September 2021–December 2021 and a post-eruption process from the end of the eruption in December 2021–May 2022. These stages with clearly different values reflect two scenarios: one corresponding to the time before the eruption with magma ascending from a 39-km depth to the surface, and a second stage corresponding to the eruption itself which includes two seismicity concentrations within the 30–40 km depth interval and a shallow concentration from 0–20 km, corresponding to the crustal reservoir and movement towards the surface. [ABSTRACT FROM AUTHOR]

The most recent years of research have shifted the perception of desalination brine from being waste to a high-value resource, in consonance with a circular economy perspective. The Canary Islands, containing the largest number of desalination plants per square kilometre in the world, are a perfect location to study its characteristics and evaluate its potential. A total of 10 heterogeneous seawater reverse osmosis plants were selected to determine the brine's physicochemical characterisation, comprising 37 parameters, and its correlation to the technical and operational aspects of the desalination plants. The results show a stable narrow range of the percentage of major ions concentration in relation to the total dissolved solids (55% Cl−, 29.5% Na+, 8% SO42−, 4% Mg2+, 1.5% Ca2+, 1.2% K+, 0.5% HCO3−, and 0.2% Br−) irrespective of specific differences between plants. The results obtained in this study are highly beneficial to industrial suppliers and future users of desalination brine valorisation (DBV) technologies, allowing an estimation of the chemical composition of a brine through knowledge only of its conductivity. Such information is crucial before investing in and optimizing DBV technologies. Nonetheless, from an environmental, economic, operational, energy-based, and R&D point of view, several improvements are required to promote their large-scale feasibility and viability. [ABSTRACT FROM AUTHOR]

The island of Lanzarote in the Canary Islands was first settled by people from northern Africa in the first millennium BC and then colonized by Spain in the late fifteenth century. This colonial legacy reflects an intensive land use driven by a European commodities market that experienced a series of boom-and-bust cycles. Although arid and seemingly resource limited, colonial farmers in the sixteenth to nineteenth centuries copied water capture techniques from the Indigenous population, were strategic in terms of field placement, and engaged in a range of niche construction techniques. An analysis of 420 soil samples for their chemical properties (e.g., pH, electrical conductivity, nutrients) has revealed that sixteenth to nineteenth agricultural infrastructure in the form of open fields, terraces, water capture basins, and mulched fields was constructed on the landscape avoiding areas of high soil salinity and placement was tailored to variations in terrain slope, elevation, and rainfall. These improvements fundamentally changed ecosystem relations resulting in increased agricultural productivity. A series of eolian and volcanic events in the eighteenth century resulted in environmental changes requiring counteractive responses and new processes of niche reconfiguration. Large tracts of land were initially removed from production, but processes of niche construction created new opportunities. These included constructing mulched pits for cultivating sweet potato and tephra mulching for enhanced moisture conservation and accelerated growth of cochineal insect (Dactylopius coccus) production on cactus host plants. Cochineal production lasted for a period of sixty years (ca. AD 1825–1885) before a collapse of the market caused by the invention of chemical substitutes. [ABSTRACT FROM AUTHOR]

This study provides evidence about the degree of socioeconomic segregation in Spain's primary schools. In particular, the analysis is based on data from Canary Islands, a Spanish region with low level of academic performance and high level of students enrolled in fully public schools. The approach used to study school segregation deepens on the contribution of the type of school funding to the overall school segregation, which is addressed using the Hutchens Index. Results suggest that differences between fully state-funded schools and private schools account for 20–30% of the total level of segregation. [ABSTRACT FROM AUTHOR]

The concept of geodiversity is becoming more widely used every year, beyond its contribution to the development of geotourism. It is estimated that geodiversity is as important as biodiversity in the functioning of Earth's natural ecosystems. Therefore, an important problem is to recognize the possibilities on integrating geodiversity in geographic education, both formal and informal. The main aim of the study is to identify the subject of educating godiversity, included in the core curricula in Spain and Canary Islands and to identify the forms, didactic tools and methods of geodiversity education existed in selected national, natural parks and geoparks of Canary Islands. The study has shown that the application of geodiversity in educational practice is still unsettled. [ABSTRACT FROM AUTHOR]

In this work, a mathematical computer simulation model is used to predict the possible energy generated from different Waves Energy Converters (WECs) in the Canary Islands. The Monte Carlo Method is the computer simulation model proposed to predict the generated energy. The Waves Energy Converter systems analyzed in the study were, the Aqua Buoy, Wave Dragon and Pelamis converters. The models were implemented and validated, with the dataset of Gran Canaria deep water buoy. This buoy belongs to a network of buoys belonging to Spain's State Ports and they cover a dataset period of 22 years. The research has concluded that it is possible to affirm that the achieved model is a strong tool to compute the possible energy of any WECs, when the power matrix is known. The model based on the Monte Carlo simulation can be used in isolated islands of the Atlantic Ocean and can be extrapolated to other regions with the same characteristics. [ABSTRACT FROM AUTHOR]