ALBERT

Description: Highlights • UAV-based thermal imaging allows precise mapping of diffusive thermal water discharge. • High tidal ranges affect fluid flow and promote larger thermal anomaly. • The La Jolla thermal anomaly is caused by a discharge of 330 ± 44 L s−1 of thermal water. • The La Jolla advective heat output (40.5 ± 5.2 MWt) can power a desalinization plant. The exploration of unexploited geothermal resources is required to encourage the use of renewable energy. This study focuses on La Jolla beach, Ensenada, Mexico. The beach hosts a thermal anomaly with temperatures of up to 52 °C at the surface and up to 93 °C at 20 cm depth. The objectives were to: map the thermal anomaly, understand the impact of tides, quantify the thermal water discharge rate and heat output, and discuss a direct use of the energy. The mapping was performed with Unmanned Aerial Vehicles equipped with optical and thermal cameras at two different dates. Additional temperature measurements were performed with a thermocouple, while the total fluid discharge was estimated from flow measurements. A comparison between the campaigns indicated that the highest surface temperature area was more than three times larger in 2019 than in 2018 (259 m2 vs. 69 m2). Such change was due to the tidal range and associated hydrostatic pressure variations. The total thermal water discharge is 330 ± 44 L s−1, which corresponds to an advective heat output of 40.5 ± 5.2 MWt. The use of this energy in a Multi-Effect Distillation desalinization plant can contribute to cover the shortage of freshwater in Ensenada.

Description: We processed three quinoa ecotypes as they are commonly consumed in a daily diet. For the treatments, quinoa seeds were washed, cooked, and/or germinated. Following treated, we used 1H NMR-based metabolomic profiling to explore differences between the ecotypes. Then, for a non-targeted and targeted food fingerprint analysis of samples, we performed multivariable data analyses, including principal component analysis (PCA), orthogonal partial least squares discriminant analysis (OPLS-DA), and hierarchical cluster analysis. From our study, we were able to discriminate each quinoa ecotype regardless of treatment based on its metabolomic profiling. Additionally, we were able to identify 30 metabolites that were useful to determine the effect of each treatment on nutritional composition. Germination increased the content of most metabolites irrespective of ecotype. In general, ecotype CQE_03 was different from ecotypes CQE_01 and CQE_02. Our phytochemical analysis revealed the effects of washing, cooking, and/or germination, particularly on saponins content.

Description: Offshore archives retrieved from marine/lacustrine environments receiving sediment from large river systems are valuable Quaternary continental records. In the present study, we reconstruct the Danube River activity at the end of the last glacial period based on sedimentological, mineralogical and geochemical analyses performed on long-piston cores from the north-west Black Sea margin. Our data suggest that the Danube River produced hyperpycnal floods throughout the ca. 33–17 ka period. Four main periods of enhanced Danube flood frequency, each of 1.5–3 kyr duration, are recorded at ca. 32.5–30.5 ka (equivalent to the first part of Heinrich Stadial –HS– 3), at ca. 29–27.5 ka (equivalent to Greenland Stadial 4), at ca. 25.3–23.8 ka (equivalent to HS 2) and at ca. 22.3–19 ka. Based on mineralogical and geochemical data, we relate these events to enhanced surface melting of the Alpine Ice Sheet (AIS) that covered ∼50,000 km2 of the Danube watershed at the Last Glacial Maximum (LGM). Our results suggest that (i) the AIS growth from the inner Alps to its LGM position in the northern Alpine foreland started from ca. 30.5 ka, ended no later than ca. 25.3 ka, and was interrupted by a melting episode ca. 29–27.5 ka; (ii) the AIS volume drastically decreased from ca. 22.3 to 19 ka, as soon as summer insolation energy at the AIS latitude increased; and (iii) HSs strongly impacted the AIS mass balance through enhanced summer surface melt. This, together with evidence of severely cool winters and the rapid expansion of sea ice in the North Atlantic, implies strong seasonality in continental Europe during stadials.

Description: Highlights: • A stable population of a migrant octocoral was found on a natural substrate. • No genetic differences were found between Mediterranean and the Red Sea specimens. • The bacterial epibiota has undergone change following migration. • Stable-isotope analysis suggests no nutritional barrier to migration for the coral. • Larval connectivity model supports Port of Hadera origin of expansion hypothesis. Abstract: The Indo-Pacific gorgonian coral Melithaea erythraea (Melithaeidae, previously Acabaria) was first recorded in the Mediterranean in 1999 in the harbor of the Hadera power station, Israel. This species is the only octocoral known to have invaded the Mediterranean Sea. In the past two decades, it has demonstrated a stable population in this harbor, and never found outside this location, not even on the adjacent natural rocky reefs. Then, during 2015, several specimens of M. erythraea were found on a natural substrate at Nahsholim, Israel, about 23 km north of the power station. This is the first evidence of this coral's existence beyond the power plant harbor. The number of colonies there suggests that the population is sustainable, but further study is needed. Although no genetic differences were found among specimens from Nahsholim, Hadera, and the Red Sea, their bacterial epibiota has undergone change following migration. The carbon source and trophic position are similar between the Red Sea and the Mediterranean, suggesting that there is no nutritional barrier to migration for the coral. The larval connectivity model supports the hypothesis that the planulae that have settled in Nahsholim originated from the Port of Hadera, although other arrival scenarios are also possible. The spread of this species suggests that the eastern Mediterranean is becoming increasingly suitable for migrating corals, joining the many other Indo-Pacific migrants that have already established populations there.

Description: Human tracks at White Sands National Park record more than one and a half kilometres of an out- and-return journey and form the longest Late Pleistocene-age double human trackway in the world. An adolescent or small adult female made two trips separated by at least several hours, carrying a young child in at least one direction. Despite giant ground sloth and Columbian Mammoth transecting them between the outbound and return journeys, the human tracks show no changes indicative of predator/prey awareness. In contrast, the giant ground sloth tracks show behaviour consistent with human predator awareness, while mammoth tracks show no such apparent concern. The human footprints are morphologically variable and exhibit left-right asymmetry, which might be due to child carrying. We explore this morphological variability using methods based on the analysis of objective track outlines, which add to the analytical toolkit available for use at other human footprint sites. The sheer number of tracks and their remarkable morphological variability have implications for the reliability of inferences made using much smaller samples as are more common at typical footprint sites. One conclusion is that the number of footprints required to make reliable biometric inferences is greater than often assumed.

Description: During the period December 2016 to March 2017 the lava dome emplaced in September–November 2016 at Volcán de Colima was partially destroyed by Vulcanian explosions. In particular, 10 moderate-large explosions were observed with heights of 2–6.8 km from the crater and with the generation of pyroclastic density currents (PDCs), shock waves and ballistics. The acoustic and seismic energies were calculated for each event. The values found are similar to other moderate-large Vulcanian explosions observed at other volcanoes, the maximum value of seismic energy was of 1.6 × 109 J and for acoustic energy 7.5 × 108 J. These values were compared with the height of the eruptive column, which resulted in a poor correlation. For the acoustic signals, the reduced pressure was greater than that commonly reported for Vulcanian explosions elsewhere. Using the time or arrival of the acoustic and seismic signals, the depth of the acoustic-seismic source was estimated at 〈310 m for nine explosions. With photogrammetry (SfM method), the volume lost during the excavation of a crater between 5 December and 12 March was estimated, the volume being 9.8 × 105 m3. The total seismic energy released during these dates was 5.7 × 109 J. With these data, a relation between the lost volume and the total seismic energy of 1.6 × 10−4 m3/J was obtained. With this relation, the volume destroyed due to future explosions could be estimated, if the seismic energy release is known.

Description: The breakup of Laurasia to form the Northeast Atlantic Realm disintegrated an inhomogeneous collage of cratons sutured by cross-cutting orogens. Volcanic rifted margins formed that are underlain by magma-inflated, extended continental crust. North of the Greenland-Iceland-Faroe Ridge a new rift–the Aegir Ridge–propagated south along the Caledonian suture. South of the Greenland-Iceland-Faroe Ridge the proto-Reykjanes Ridge propagated north through the North Atlantic Craton along an axis displaced ~150 km to the west of the rift to the north. Both propagators stalled where the confluence of the Nagssugtoqidian and Caledonian orogens formed an ~300-km-wide transverse barrier. Thereafter, the ~150 × 300-km block of continental crust between the rift tips–the Iceland Microcontinent–extended in a distributed, unstable manner along multiple axes of extension. These axes repeatedly migrated or jumped laterally with shearing occurring between them in diffuse transfer zones. This style of deformation continues to the present day in Iceland. It is the surface expression of underlying magma-assisted stretching of ductile continental crust that has flowed from the Iceland Microplate and flanking continental areas to form the lower crust of the Greenland-Iceland-Faroe Ridge. Icelandic-type crust which underlies the Greenland-Iceland-Faroe Ridge is thus not anomalously thick oceanic crust as is often assumed. Upper Icelandic-type crust comprises magma flows and dykes. Lower Icelandic-type crust comprises magma-inflated continental mid- and lower crust. Contemporary magma production in Iceland, equivalent to oceanic layers 2–3, corresponds to Icelandic-type upper crust plus intrusions in the lower crust, and has a total thickness of only 10–15 km. This is much less than the total maximum thickness of 42 km for Icelandic-type crust measured seismically in Iceland. The feasibility of the structure we propose is confirmed by numerical modeling that shows extension of the continental crust can continue for many tens of millions of years by lower-crustal ductile flow. A composition of Icelandic-type lower crust that is largely continental can account for multiple seismic observations along with gravity, bathymetric, topographic, petrological and geochemical data that are inconsistent with a gabbroic composition for Icelandic-type lower crust. It also offers a solution to difficulties in numerical models for melt-production by downward-revising the amount of melt needed. Unstable tectonics on the Greenland-Iceland-Faroe Ridge can account for long-term tectonic disequilibrium on the adjacent rifted margins, the southerly migrating rift propagators that build diachronous chevron ridges of thick crust about the Reykjanes Ridge, and the tectonic decoupling of the oceans to the north and south. A model of complex, discontinuous continental breakup influenced by crustal inhomogeneity that distributes continental material in growing oceans fits other regions including the Davis Strait, the South Atlantic and the West Indian Ocean.

Description: Highlights: • Enhanced surface N2O saturations were found between 5°S and 10°S in the SWIO. • The SWIO was a rather weak source of N2O to the atmosphere. • A distinct N2O maximum was found at about 1000 m. • The distributions of NH2OH in the water column were highly variable. • Nitrification was the major formation pathway of N2O in the SWIO. The southwestern basin of the Indian Ocean (SWIO) remains a rather under-sampled region with regard to nitrogen-cycle processes. Here we present the results of extensive nitrous oxide (N2O) measurements as well as the first reported open ocean measurements of hydroxylamine (NH2OH). Enhanced N2O sea-to-air fluxes were found in the zonal band between 5°S and 10°S as a result of wind-driven upwelling, and N2O depth profiles showed supersaturation throughout the water column with a distinct maximum at about 1000 m. Excess N2O (ΔN2O) was found to be positively correlated with apparent oxygen utilization (AOU) and nitrate. Although the water column distribution of NH2OH was highly variable, combined analysis with N2O and nutrient data allows us to argue for nitrification as the major formation pathway of N2O in the SWIO.

Description: Harmful marine bacteria, such as Vibrio or Aeromonas species, typically exist at low abundance in ocean environments but represent a reservoir from which epidemics can arise. Particularly, Vibrio strains and their associated infections are on the rise globally due to increasing sea surface temperature representing an emergent threat for human and animal health also being responsible for large economic losses in the aquaculture industry worldwide. New technological approaches are needed to improve strategies targeting these pathogens. This review discusses new approaches based on improved sampling strategies and novel analytical methods offering increased accuracy, high throughput, and informativeness to study and detect microbial pathogens in the marine environment. Detecting and characterizing ultra-low-abundance pathogenic strains can serve as a critical tool in risk management and outbreak prevention of diseases caused by emerging marine pathogens.

Description: Carbon capture and storage (CCS) is a key technology to reduce carbon dioxide (CO2) emissions from industrial processes in a feasible, substantial, and timely manner. For geological CO2 storage to be safe, reliable, and accepted by society, robust strategies for CO2 leakage detection, quantification and management are crucial. The STEMM-CCS (Strategies for Environmental Monitoring of Marine Carbon Capture and Storage) project aimed to provide techniques and understanding to enable and inform cost-effective monitoring of CCS sites in the marine environment. A controlled CO2 release experiment was carried out in the central North Sea, designed to mimic an unintended emission of CO2 from a subsurface CO2 storage site to the seafloor. A total of 675 kg of CO2 were released into the shallow sediments (~3 m 49 below seafloor), at flow rates between 6 and 143 kg/d. A combination of novel techniques, adapted versions of existing techniques, and well-proven standard techniques were used to detect, characterise and quantify gaseous and dissolved CO2 in the sediments and the overlying seawater. This paper provides an overview of this ambitious field experiment. We describe the preparatory work prior to the release experiment, the experimental layout and procedures, the methods tested, and summarise the main results and the lessons learnt.