ALBERT

Description: We demonstrate a flexible strategy for local tsunami warning that relies on regional geodetic and seismic stations. Through retrospective analysis of four recent tsunamigenic events in Japan and Chile, we show that rapid earthquake source information, provided by methodologies developed for earthquake early warning, can be used to generate timely estimates of maximum expected tsunami amplitude with enough accuracy for tsunami warning. We validate the technique by comparing to detailed models of earthquake source and tsunami propagation as well as field surveys of tsunami inundation. Our approach does not require deployment of new geodetic and seismic instrumentation in many subduction zones, and could be implemented rapidly by national monitoring and warning agencies. We illustrate the potential impact of our method with a detailed comparison to the actual timeline of events during the recent 2015 Mw8.3 Illapel, Chile earthquake and tsunami that prompted the evacuation of 1 million people.

Description: In many northern temperate regions, the water color of lakes has increased over the past decades (“lake browning”), probably caused by an increased export of dissolved organic matter from soils. We investigated if the increase in water color in two lakes in Norway has resulted in increased burial of organic carbon (OC) and mercury (Hg) in the sediments, and if the Hg was prone to methylation. Lake Solbergvann experienced a 3-fold water color increase, and OC burial increased ~2-fold concomitant to the water color increase. This lake had prolonged periods of anoxic bottom water, and anoxic OC mineralization rates were only about half of the oxic OC mineralization rates (7.7 and 17.5 g C m -2 yr -1 , respectively), contributing to an efficient OC burial. In Lake Elvåga, where water color increase was only ~2-fold and bottom water was oxygenated, no recent increase in OC burial could be observed. Hg burial increased strongly in both lakes (3-fold and 1.6-fold in Lake Solbergvann and Lake Elvåga, respectively), again concomitant to the recent water color increase. The proportion of methylated Hg (MeHg) in surficial sediment was one order of magnitude higher in Lake Elvåga (up to 6% MeHg) than in Lake Solbergvann (0.2-0.6% MeHg), probably related to the different oxygenation regimes. We conclude that lake browning can result in increased OC and Hg burial in lake sediments, but the extent of browning and the dominating mode of sediment respiration (aerobic or anaerobic) strongly affect burial and fate of OC and Hg in sediments.

Description: Abstract Aim Most of the fundamental questions in conservation biogeography require the description of species geographic boundaries and the identification of discrete biological units within these boundaries. International conservation efforts and institutions rely mainly on traditional taxonomic approaches for defining these boundaries, resulting in significant cryptic diversity going undetected and often extinct. Here, we combine high‐throughput genomic data with publicly available environmental data to identify cryptic diversity in the threatened bird's‐eye primrose (Primula farinosa). We aim to characterize evolutionary lineages and test whether they co‐occur with changes in environmental conditions. These lineages can be used as intraspecific units for conservation to enhance assessments regarding the status of threatened species. Location Europe and temperate Asia (latitude, 40–65°N; longitude, 10°E–115°W). Methods We genotyped 93 individuals from 71 populations at 1,220 loci (4,089 SNPs) across the Eurasian distribution of P. farinosa. We used phylogenomic and population structure approaches to identify intraspecific lineages. We further extracted statistically derived and remotely sensed environmental information, that is land cover, climate and soil characteristics, to define the biotic and abiotic environment inhabited by each lineage and test for niche similarities among lineages. Additionally, we tested for isolation by distance among populations and applied linear and polynomial regressions to identify lineage‐environment associations. Results Analyses of genomic data revealed six major lineages within P. farinosa corresponding to distinct geographic areas. Niche similarity tests indicated that lineages occupy distinct abiotic and biotic space. Isolation by distance indicated that geography alone cannot explain genetic divergence within P. farinosa, while lineage‐environment associations suggested potential adaptation to different abiotic conditions across lineages. However, relationships with the land cover classes, a proxy for habitat, were weaker. Main conclusion Our results highlight the need for incorporating intraspecific diversity in global assessments of species conservation status and the utility of genomic and publicly available environmental data in conservation biogeography.

Description: Abstract One of the main problems of hydrologic/hydrodynamic routing models is defining the right set of parameters, especially on inaccessible and/or large basins. Remote Sensing techniques provide measurements of the basin topography, drainage system and channel width, however current methods for estimating riverbed elevation are not as accurate. This paper presents methods of altimetry data assimilation for estimating effective bathymetry of a hydrodynamic model. We tested past altimetry observations from satellites ENVISAT, ICESAT and JASON 2 and synthetic altimetry data from satellites ICESAT 2, JASON 3, SARAL and SWOT to assess future/present mission's potential. The data assimilation (DA) methods used were Direct Insertion, Linear Interpolation, the SCE‐UA optimization algorithm and an adapted Kalman Filter developed with hydraulically based variance and covariance introduced in this paper. The past satellite altimetry data assimilation was evaluated comparing simulated and observed water surface elevation (WSE) while the synthetic altimetry DA were assessed through a direct comparison with a “true” bathymetry. The SCE‐UA and hydraulically based Kalman Filter methods presented the best performances, reducing WSE error in 65% in past altimetry data experiment and reducing biased bathymetry error in 75% in the synthetic experiment, however the latter method is much less computationally expensive. Regarding satellites, it was observed that the performance is related to the satellite inter‐track distance, as higher number of observation sites allows more accurate bed elevation estimation.

Description: We studied the fate of Cu in contaminated semiarid soils from two areas with different mining activities in central Chile. Several regression models were evaluated to use soil physicochemical characteristics to predict solubility, partitioning, and activity of Cu. Furthermore, we hypothesize that the type of Cu mining compound (smelter dust versus tailing sand) can be another important variable determining the bioavailability of Cu. In the studied neutral to alkaline soils, soil organic matter (SOM) enhanced Cu solubility most probably through the formation of organic complexes with dissolved organic C (DOC). As a consequence, Cu solubility and partitioning were better explained by DOC concentration than by SOM content. On the other hand, Cu activity was mainly related to soil pH and was not affected by DOC. Although we found differences between the two study areas, Cu solubility and partitioning might not be as dependent upon the origin of the Cu mining compound as upon other physiochemical characteristics that influence the concentration and characteristics of DOC. Total Cu, pH, and DOC would be the most important variables to consider on Cu solubility, however, data about the nature of SOM may certainly improve the prediction models. Thus, multiple binding site models between Cu and DOC should be studied to improve predictions of Cu solubility.

Description: Submarine canyons cutting across the continental shelf can modulate the cross-shelf circulation being effective pathways to bring water from the deep ocean onto the shelf. Here, we use 69 days of moored array observations of temperature and ocean currents collected during the spring of 2013 and winter-spring 2014, as well as shipboard hydrographic surveys and sea-level observations to characterize cold, oxygen poor and nutrient-rich upwelling events along the Biobio Submarine Canyon (BbC). The BbC is located within the Gulf of Arauco at 36° 50'S in the Central Chilean Coast. The majority of subtidal temperature at 150 m depth is explained by subtidal variability in alongshore currents on the canyon with a lag of less than a day ( r 2 =0.65). Using the vertical displacement of the 10° and 10.5°C isotherms, we identified nine upwelling events, lasting between 20 hours to 4.5 days, that resulted in vertical isothermal displacements ranging from 29 to 137 m. The upwelled water likely originated below 200 m. Majority of the cooling events were related with strong northwards (opposite Kelvin wave propagation) flow and low pressure at the coast. Most of these low pressure events occur during relatively weak local wind forcing conditions, and were instead related with Coastal Trapped Waves (CTWs) propagating southwards from lower latitudes. These cold, high-nutrient, low-oxygen waters may be further upwelled and advected into the Gulf of Arauco by wind forcing. Thus, canyon upwelling may be a key driver of biological productivity and oxygen conditions in this Gulf. This article is protected by copyright. All rights reserved.

Description: We have investigated the kinetics and mechanism of the reaction between 3-methylbenzenediazonium, 3MBD, ions and catechol (1,2-dihydroxybenzene, [CAT]) in aqueous buffer solution under acidic conditions by employing spectrometric UV/VIS. The variation of the observed rate constant, k obs , with the acidity at a given [CAT] follows an upward curve, with rate enhancements of up to 20-fold on going from pH  = 3.0 up to pH  = 5.0, suggesting that the reaction takes place with the monoanionic form of [CAT]. At relatively high acidities, the variation of k obs with [CAT] is linear with an intercept very close to the value for the thermal decomposition of 3MBD; however, a decrease in the acidity leads to saturation kinetics profiles with non-zero pH-dependent intercepts, prompting us to propose a reaction mechanism comprising two consecutive equilibrium processes involving the bimolecular, reversible, formation of a highly unstable Z -diazo ether, which undergoes isomerization to the E -isomer through a unimolecular step. The results highlight the complexity of the reactions of arenediazonium ions with nucleophilic arenes containing two or more hydroxy groups and are valuable to exploit arenediazonium ions as chemical probes to determine antioxidant distributions. Copyright © 2016 John Wiley & Sons, Ltd. The non-zeron, pH dependent, intercepts of the saturation kinetics suggest a mechanism of the type.

Description: Abstract In Eastern Boundary Upwelling Systems (EBUS), the upwelling‐favorable wind speeds decrease toward the coast in the so‐called wind drop‐off coastal strip, which has been shown to be influential on the coastal upwelling dynamics, particularly in terms of the relative contributions of Ekman drift and Ekman suction to coastal upwelling. Currently, the wind drop‐off length scale is not properly resolved by the atmospheric forcing of regional ocean models in EBUS, featuring a smoother cross shore wind profile that results in stronger near shore speeds that could partly explain the coastal cold bias often found in those model simulations. Here, as a case study for the upwelling system off Central Chile, the sensitivity of upwelling dynamics to the coastal wind reduction is investigated using a regional oceanic model (ROMS). Coastal wind profiles at different resolutions are first generated using a regional atmospheric model, validated from altimeter data, and then used to correct the coarse atmospheric wind forcing used for sensitivity experiments with ROMS. It is shown that the wind drop‐off correction induces a reduction in the oceanic coastal jet intensity, a stronger poleward undercurrent and a coherent offshore Ekman drift. It also yields a significant reduction of the cold bias along the coast compared to the simulation with “uncorrected” winds. Such reduction cannot be solely explained by the reduced Ekman transport only partially compensated by increase in Ekman suction. The analysis of the surface heat budget reveals in fact that an important contributor to the cooling reduction along the coast in the presence of coastal wind drop‐off is the heat flux term mediated by the reduction in the mixed‐layer depth. Overall, our results illustrate the non‐linear response of the upwelling dynamics to the coastal wind profiles in this region.