Coast Of Central Chile Research Articles

Seasonal variability of gillnet selectivity in Chilean hakeMerluccius gayi gayi(Guichenot, 1848)

This study examines the seasonal variability in gillnet size selectivity for the main Chilean hake (Merluccius gayi gayi) fishery off the coast of central Chile. Selectivity estimates were based on five gillnet mesh sizes (50, 60, 70, 80, 90 mm) in four traditional fishing areas, and during periods of low and high reproductive activity. Average fish length caught in the earlier period (low reproductive activity) was 30.8 cm LT (±4.17), and significantly longer (p < .05) at 35.9 cm TL (±6.15) in the latter period (high reproductive activity). For males, the selectivity factor was similar in both periods, thus the estimated modal lengths did not differ seasonally (p > .05). For females, however, both the selectivity factor and the estimated modal lengths changed significantly depending on the time of year (p < .05). A significant increment was estimated in the girth/perimeter ratio and condition factor during the period of higher reproductive activity. This change in the fish girth of females during spawning helps explain the significant reduction in their selectivity factor estimates in August–October.

Wave energy assessment in the central-south coast of Chile

This paper presents an assessment of the wave energy resource in nearshore waters along the central coast of Chile (Lat.:32.5° S to 42.5° S). The assessment is built upon the combined use of hindcast and measured data collected specifically for this goal. Offshore and nearshore data at a number of locations were collected with buoys and ADCPs, with dwell times ranging from 3 up to 12 months. These were used to assess the accuracy of modeled data at the both offshore and nearshore locations. Modeled offshore data comprises three hourly sea states obtained from a third generation ocean wave model, covering the 1989–2013 period, thereby allowing long-term estimates. By using the wave model SWAN, these data was propagated to the nearshore shallow waters to obtain modeled wave climate along the entire section of coast. Validation results indicate good model skill, where both offshore and nearshore results are within 10% of the measured data, with an over prediction of wave power. The long-term wave power estimates show an increase of the median power with increasing latitude, fluctuating between 20 and 35 kW/m in areas near the coast. Monthly and seasonal variability also increase with latitude, with higher energy events present during the winter season. These results are qualitatively consistent with previous assessments in the area, albeit the present results are consistently 5–10 kW/m smaller, which suggests that previous non calibrated assessments may have overpredicted the wave power by about 20%.

A 7000‐year high‐resolution lake sediment record from coastal central Chile (Lago Vichuquén, 34°S): implications for past sea level and environmental variability

ABSTRACTWe present a 7‐ka environmental reconstruction based on sedimentological and geochemical data from Lago Vichuquén, a coastal eutrophic lake in central Chile (34°48′S, 72°03′ W, 4 m a.s.l.). A relatively shallow and restricted marine environment with low productivity, high detrital input and dominant anoxic conditions in the Vichuquén Basin occurred from 7.0 to 6.5 cal ka BP. Rapid onset of a Holocene marine transgression at 6.5 cal ka BP favoured deeper and more biologically productive environments that existed until 2.8 cal ka BP. Bioproductivity changes during the mid‐Holocene (6.5–4.2 cal ka BP) were related to upwelling dynamics controlled by the intensity of the South‐east Pacific Anticyclone (SPA). Periods with lower organic productivity and dominant anoxic conditions reflect an increased intensity of SPA (increased upwelling) and decreased precipitation. A shift at ∼4.0 cal ka BP reflects the onset of modern Southern Westerly Winds and El Niño‐Southern Oscillation patterns. Tectonic uplifting and geormorphological activity (dune advancement) are possible reasons behind the Vichuquén Basin closure at ∼1.2 cal ka BP, leading to a low bioproductivity lacustrine environment which has developed until the present. Copyright © 2017 John Wiley &amp; Sons, Ltd.

Historical analysis of somatic growth of Chilean hake (Merluccius gayi gayi) off central coast of Chile

Somatic growth was studied in the Chilean hake stock off central coast of Chile, through the application of Von Bertalanffy equation (vB) as a non-linear mixed effect model (NLME) on length-at-agedata derived from otolith readings made at Instituto de Fomento Pesquero since 1972. Average growth rates for each year from 1972 to 2009 were estimated. Growth parameters of vB curves were analyzed for three major periods regarding changes in stock biomass (1972-1990, 1991-2003 and 2004-2009). Results indicated that the average growth rate showed inter-annual variations that did not exceed ±15 cm of total length around the historical average of males and females, showing no persistent tendency towards sustained increase or decrease in somatic growth rate. Growth curves obtained with the vB parameters, estimated for the three periods, showed a similar trajectories until age 7 and 8 years, in both male and females. Changes after this age may be a result of a decrease of larger fish removed by the selective effect of fishing, which triggered variations in the fitted curves, but not necessarily changes in somatic growth of these ages in the population. The results demonstrated that the individual growth of hake has not changed significantly since 1972, without observing a density-dependent effect with decreasing abundance.

Reconstruction of coseismic slip from the 2015 Illapel earthquake using combined geodetic and tsunami waveform data

AbstractOn 16 September 2015, a moment magnitude (Mw) 8.3 earthquake struck off the coast of central Chile, generating a large tsunami with nearby coastal wave heights observed on tide gauges in Chile and Peru of up to 4.7 m and distal observations of over 40 cm in the Kuril Islands across the Pacific Ocean. Through a transcoastal geodetic study, including tsunami time series recorded at open ocean pressure gauges, subaerial deformation observed through interferometric synthetic aperture radar from the Sentinel‐1 A satellite and continuous GPS, we identify the location and extent of coseismic slip. We find that most coseismic slip was concentrated in a patch immediately offshore, with little modeled slip near the trench. This result satisfies the tsunami waveforms measured in the deep ocean north of the rupture area, with wave heights up to 10 cm. While the event exhibits some features of a slow tsunami earthquake (moderately large tsunami and possible slow second‐stage rupture), our inversion results do not require substantial near‐trench rupture. However, the prevalence of large and shallow thrust along subduction megathrusts along central Chile raises the question of the likelihood of future such events and the implications for future hazardous tsunamigenic earthquakes.

Parasite burden in decapod crustaceans from the central coast of Chile: is there any association with the relationship with definitive host abundances?

Crustaceans play an important role in parasite life cycles, serving as second intermediate hosts. However, there are scarce parasitological studies in crustaceans from the rocky intertidal habitats, in Chile and around de world. In this study we aimed to record the parasites in decapod crustaceans, compare their parasitic loads between localities and relate them with the abundance of the definitive hosts (fishes and birds). Between July and September 2013, 409 crustacean specimens, corresponding to 16 species, were collected from the rocky intertidal zone of two localities of central Chile (33°S), Las Cruces and Montemar. Of out the sample, 65.5% was parasitized; counting 2,410 metacercariae and 18 nematodes. One group of these metacercariae belonged to the family Opecoelidae; while others corresponded to the family Microphallidae. Nematodes belonged to the family Cystidicolidae. The highest prevalence and abundance of opecoelids were in P. violaceus (96.9%, 13.59 ± 17.50 parasites/crustacean), microphallids were mostly recorded in the crab Petrolisthes tuberculosus (42.3%, 11.08 ± 4.8 parasites/crustacean), while cystidicolids were less prevalent and abundant than digenean at both localities. Parasite loads was affected by body size, locality and species of crustacean hosts. No association was found between parasite loads in these intermediate hosts and the abundance of definitive hosts. The low relationships between parasite loads and host abundances may be due to several reasons, such as a wide trophic spectrum and great capacity of movement, which would not contribute to the parasite transmission and the direct relationship with the definitive host abundances.

Distribution, habitat use and plant associations of Moluchia brevipennis (Saussure, 1864) (Blattodea: Ectobiidae): an endemic cockroach from Chilean Mediterranean Matorral biome

Wild cockroaches are often described as abundant and diverse insects from wet tropical zones; however, they can also be found in arid and semiarid areas. It is proposed that in these drier environments cockroach survival may dependent on its tight association with native plant species. In this work, using bait trapping and active collection methods, we surveyed cockroach species along central Chile coastal scrubland; the southern limit of the semiarid Mediterranean Matorral biome in the Neotropical Region (32°S). Based on morphological and DNA barcoding methods we found that our collected cockroaches belonged to native species Moluchia brevipennis (Saussure, 1864) (Blattodea: Ectobiidae). Furthermore, thanks to field sampling, we noticed for the first time that M. brevipennis predominantly can be found in patches of native vegetation from Matorral biome, for instance, associated to endemic plant species from Puya (Bromeliaceae) genus, where we recorded these wild cockroaches feeding on flowers at dusk. Under the light of these findings, we discuss the relevance of the association between M. brevipennis and native plants for its survival in this semiarid habitat, its potential ecological function and the ongoing hazards for native insect species resulting from nearby urban sprawl in coastal central Chile.

The September 16, 2015 Illapel tsunami, Chile – Sedimentology of tsunami deposits at the beaches of La Serena and Coquimbo

On September 16, 2015, a Mw 8.3 earthquake occurred off the coast of central Chile, 46km west of the town of Illapel. The quake caused a tsunami impacting the coast mainly between the towns of Caldera (c. 27°S) and Pichidangui (c. 32°S). At Coquimbo and La Serena (c. 30°S) the tsunami attained large wave heights on the order of 4.5m leading to flooding and destruction of infrastructure including the coastal road. We report the results of a post-tsunami sedimentological field survey undertaken in October 2015 focussing on the beaches of Coquimbo and La Serena.At Playa Changa, a beach at Coquimbo affected by the highest waves, the tsunami destroyed large parts of the coastal road embankments on both the seaward and landward sides. On the landward side the tsunami distributed triangular concrete construction elements of the embankment across the coastal plain. On the seaward side granite boulders of up to 2t were ripped out of the coastal road embankment and transported onto the beach. Sand used in construction of the embankment was redistributed across the beach as an outflow deposit.At La Serena we observed a laminated package of tsunami deposits along a 20m long trench perpendicular to the coast. The sediments have erosive basal surfaces with an amplitude of up to 50cm. The deposit thickness varies between 10 and 50cm. The sedimentary package consists of 6 mostly lenticular layers of variable thickness and spatial extent, ranging between dark laminae a few millimeters thick and rich in heavy minerals, and lighter colored sand layers up to 15cm thick. Grain size distributions are moderately well to well sorted and unimodal with modes between 1.3 and 2.0 Φ (medium sand). Cross-beds in the lower four layers indicate deposition from tsunami inflow, cross bedding in the second layer from the top layer records outflow. The abundance of cross beds and laminae suggests that deposition of sand from bed load traction currents was the prevailing mode of deposition.Water escape structures occur as small sand diapirs and volcanoes. Water escape through small volcanoes appears to have been coeval to formation of the overlying layer by traction deposition. This synchroneity is indicated by sand sourced from the lower layer which has been preserved as a thin plume deformed in the downcurrent, i.e. landward direction in the newly forming upper layer. Other sediment layers show sand diapirs intruding up to 15cm into the overlying tsunami deposit.The assemblage of sedimentary structures indicates rapid deposition, from one or several waves associated with the tsunami event.

Integrating stakeholder perceptions and preferences on ecosystem services in the management of coastal areas

The consideration of stakeholders' perceptions and preferences on different ecosystem services, identifying potential conflict areas, is essential for operationalizing integrated management plans. In the central coast of Chile, several traditional fishing resources are overexploited and conflicts between users might arise with the increasing demand of both traditional and new uses. The principal groups of users in coastal areas were characterized in order to generate information that advances towards integrative approaches in the region. Face-to-face surveys to fishermen, tourists and permanent residents were conducted in six coastal sites to identify what these groups value the most, assessing at the same time if differences in perceptions and use might suggest future conflicts between users associated to coastal planning. Participants had to prioritize a list of coastal attributes associated with ecosystem services. Results show variability in prioritization of coastal attributes amongst groups of users, however, variability across sites was low. Fishermen showed a tight economic and cultural dependency on provisioning services; however, their general perception was of decreasing catches and a shift to less valued resources and habitat structuring species as traditional ecosystem services deteriorate. Tourists and residents had the most homogenous perceptions, and agreed on the prioritization of intangible services, such as the quietness and scenery of the coast. Nevertheless, deterioration of the environment was perceived as relevant by the inhabitants of the study area, reflecting a potential conflict between the current increase in tourist influx and resource demand. Therefore, increasing recreational use needs to be managed, ensuring the resilience of the traditional fisheries and adopting effective actions that should encompass wider ecosystem objectives. However, the real challenge for integrated management is the incorporation of intangible values in conservation objectives.

Early aftershocks and afterslip surrounding the 2015 Mw 8.4 Illapel rupture

On 16 September 2015, the Mw 8.4 Illapel earthquake ruptured a section of the subduction thrust on the west coast of central Chile. The mainshock was followed by numerous aftershocks including some normal-faulting events near the trench. We apply a template matching approach to improve the completeness of early aftershocks within one month of the mainshock. To constrain the distribution of afterslip, we utilize repeating earthquakes among the aftershocks and perform a joint slip inversion of postseismic GPS and InSAR data. The results show that the aftershock zone abruptly expands to the south ∼14 h after the mainshock while growing relatively continuously to the north within the first day. The repeating earthquakes accompanying the early expansion suggest that aseismic afterslip on the subduction thrust surrounding the coseismic rupture is an important triggering mechanism of aftershocks in addition to stress transfer or poroelastic effects. An energetic earthquake sequence near the trench initiated with a M 4.6 event ∼3.5 h after the mainshock, suggesting delayed triggering by the static or dynamic stress changes induced by the mainshock. The spatial distribution of repeating earthquakes and the geodetic-inverted afterslip are consistent and appear to wrap around the large coseismic slip patch. Both data sets suggest that the largest cumulative afterslip is located at ∼30.5°S to the north of the mainshock rupture zone. The estimated postseismic moment released in the first ∼24 days of afterslip is equivalent to an earthquake of Mw 7.5. The afterslip illuminates the velocity strengthening sections of the plate interface that surround the mainshock rupture, consistent with plate coupling models inferred from interseismic GPS velocities.

Reconstructing drowned terrestrial landscapes. Isotopic paleoecology of a late Pleistocene extinct faunal assemblage: Site GNL Quintero 1 (GNLQ1) (32° S, Central Chile)

Site GNL Quintero 1 (GNLQ1), located nearshore at Quintero bay in the central coast of Chile (32° S), is the only documented Late Pleistocene drowned terrestrial site along the Pacific coast of South America. During the last decade, through underwater archaeological operations conducted at GNLQ1, several clusters of shallowly buried bone deposits were documented and excavated, revealing a well preserved high-resolution in situ context. Taxonomic analysis of the faunal assemblage recovered yielded at least 26 individuals comprising extinct Camelidae, Cervidae, Equidae, Mylodontidae, and Xenarthra as well as Canidae, Myocastoridae, Octodontidae, Cricetidae, among others. By conducting stable isotope analyses (δ13Cap and δ18Oap) on mammalian bioapatite, we aim to perform a first characterization of the GNLQ1 taxa paleoecology and carry out paleoenvironmental inferences. Regional records for the Last Glacial Maximum (LGM) suggest lower sea surface temperatures and more humid climatic conditions for Central Chile. Isotopic data obtained suggests a landscape of mixed vegetation areas, in good agreement with the sedimentary context of the fossil remains and a preliminary Quintero paleolandscape model: a wetland environment developed under semiarid conditions prior to post-glacial sea level rise, with GNLQ1 located >6 km inland as the paleoshoreline was further out on the continental shelf.

On subsurface cooling associated with the Biobio River Canyon (Chile)

AbstractSubmarine 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 (r2 = 0.65). Using the vertical displacement of the 10° and 10.5°C isotherms, we identified nine upwelling events, lasting between 20 h 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 northward (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.

Results of Post-Field Survey on the Mw 8.3 Illapel Earthquake Tsunami in 2015

On 16 September 2015, a Mw 8.3 earthquake occurred off the coast of Illapel, Central Chile, generating a tsunami that caused moderate damage along the coast of Central Chile. To investigate tsunami damage and evacuation responses, we conducted a post-tsunami field survey between La Serena and Concón. The average tsunami inundation height in the survey area was 3–4 m; however, in the innermost corner of Coquimbo Bay, which was shielded from the tsunami source by the Coquimbo Peninsula, the tsunami inundation height was 6.0–6.2 m, decreasing gradually along the coast away from the corner. This phenomenon was also confirmed around Tongoy Bay, which is geographically similar to Coquimbo Bay. Based on our results, we hypothesize that the tsunami was diffracted and refracted by the peninsula, and then converged on the innermost corner of the bay, located behind the peninsula. Interviews with local residents confirmed that most people evacuated immediately after feeling strong seismic motion, but before the tsunami warning and evacuation orders were issued. However, several people did not evacuate, either because they believed that they were located in a safe place, or because they wanted to protect their property.

Imposex and butyltin contamination still evident in Chile after TBT global ban

Imposex in gastropods (Acanthina monodon, Oliva peruviana and Xanthochorus cassidiformis), butyltin levels in surface sediments (Coquimbo and Concepcion) and tissues (Valparaiso and Concepcion) were assessed in three areas under the influence of maritime activities along the central Chilean coast. The highest TBT concentrations were observed in São Vicente Bay (Concepcion), reaching 122.3ngSng−1 in surface sediments and 59.7ngSng−1 in gastropods tissue, while in Valparaiso ranged from 7.4 to 15.8ngSng−1 in biota. The lowest TBT concentrations were detected in sediments from Coquimbo (<2ngSng−1), which can be attributed to a much lower ship/boat traffic (probably using TBT free products) in association to local oceanographic conditions. Despite DBT and MBT were the predominant analytes, recent inputs of TBT were evident in some areas. In fact, fishing boats may be a relevant source since they were the predominant maritime activity in the most contaminated sites. In addition, the absence of significant differences within BTs levels between both genders of A. monodon suggests that tissues from distinct sexes can be indistinctly used for future contamination studies. Imposex incidence was detected in 11 out of 15 sampled sites, indicating that environmental levels of TBT have been sufficient to induce deleterious effects on the exposed organisms. Thus, the impacts caused by TBT in Chilean coastal areas were detectable and consistent with other studies performed in South America. This present environmental contamination is probably due to the lack of regulations forbidding the use of TBT-based antifouling paints in Chile.

Biogeochemical characteristics of a long-lived anticyclonic eddy in the eastern South Pacific Ocean

Abstract. Mesoscale eddies are important, frequent, and persistent features of the circulation in the eastern South Pacific (ESP) Ocean, transporting physical, chemical and biological properties from the productive shelves to the open ocean. Some of these eddies exhibit subsurface hypoxic or suboxic conditions and may serve as important hotspots for nitrogen loss, but little is known about oxygen consumption rates and nitrogen transformation processes associated with these eddies. In the austral fall of 2011, during the Tara Oceans expedition, an intrathermocline, anticyclonic, mesoscale eddy with a suboxic (&lt; 2 µmol kg−1 of O2), subsurface layer (200–400 m) was detected ∼ 900 km off the Chilean shore (30° S, 81° W). The core of the eddy's suboxic layer had a temperature-salinity signature characteristic of Equatorial Subsurface Water (ESSW) that at this latitude is normally restricted to an area near the coast. Measurements of nitrogen species within the eddy revealed undersaturation (below 44 %) of nitrous oxide (N2O) and nitrite accumulation (&gt; 0.5 µM), suggesting that active denitrification occurred in this water mass. Using satellite altimetry, we were able to track the eddy back to its region of formation on the coast of central Chile (36.1° S, 74.6° W). Field studies conducted in Chilean shelf waters close to the time of eddy formation provided estimates of initial O2 and N2O concentrations of the ESSW source water in the eddy. By the time of its offshore sighting, concentrations of both O2 and N2O in the subsurface oxygen minimum zone (OMZ) of the eddy were lower than concentrations in surrounding water and “source water” on the shelf, indicating that these chemical species were consumed as the eddy moved offshore. Estimates of apparent oxygen utilization rates at the OMZ of the eddy ranged from 0.29 to 44 nmol L−1 d−1 and the rate of N2O consumption was 3.92 nmol L−1 d−1. These results show that mesoscale eddies affect open-ocean biogeochemistry in the ESP not only by transporting physical and chemical properties from the coast to the ocean interior but also during advection, local biological consumption of oxygen within an eddy further generates conditions favorable to denitrification and loss of fixed nitrogen from the system.

¿Utópolis o distópolis?: producción inmobiliaria y metropolización en el litoral central de Chile (1992-2012)

Urban sprawl has taken varied forms, functions, and structures in recent decades. The aim of this article is to analyze how production processes of utopolis became distopolis through negative socio-spatial effects in the central coast of Chile between 1992 and 2012. Two stages are identified in the process: an earlier expansion of the secondary housing and another one of building main housing with great spatial integration and a strong process of urban sprawl in the central urban macrozone of Chile.

EFICIENCIA DE LA Ammophila arenaria EN ATRAPAR SEDIMENTOS TRANSPORTADOS POR EL VIENTO.

The object of this paper was to evaluate the efficiency of the Ammophila arenaria in catching sediments. It was made by comparing sectors with dense vegetation cover and bare dunes (blowout), on foredunes at the central coast of Chile (38° 05 ' S). Vertical sand traps were placed across transects at the beginning of the dune formation, and at the base and the top of the foredune, in order to determine the aeolian sediment transport rates. The results showed that in the windward slope with dense vegetation the sand grains were trapped and an insignificant amount (3%) advanced behind the dunes. On the other hand, on the blowout, the sand windblown increased exponentially to the top reaching values up to 447% with respect to those found at the base of the blowout. The great capacity of the Ammophila arenaria in catching sediments is verified and it considers that foredunes with dense covers of Ammophila arenaria are like true natural traps for the evaluation of aeolian sand transport rates.

Modelling the seasonal dynamics of the Peru-Chile Undercurrent off Central Chile (30–40°S)

The seasonal variability of the hydrology and the poleward subsurface Peru-Chile Undercurrent (PCUC) off the central Chilean coast (29–41°S) were examined using a high-resolution regional model. The model realistically reproduced observed sea level variability, such as intense anticyclonic eddies, the offshore intensification of the poleward flow and the reduced nearshore equatorward flow during autumn, as well as the equatorward intensification of nearshore meandering flow during spring. Values for geostrophic eddy kinetic energy were high along the coast between 30° and 37°S, and lower south of this area. The modelled poleward undercurrent showed latitudinal variability in velocity and transport. The maximum average transport reported was 0.8Sv near 30°S, consistent with previous modelling studies and estimations derived from in situ observations. The poleward reduction in undercurrent strength was shown to be partly generated by the poleward decrease in wind stress curl and by the formation of a westward jet near 35°S associated with westward-propagating eddies. A Lagrangian analysis of the modelled water parcels transported by the undercurrent shows that only 14–20% of the subsurface floats transported by the undercurrent upwelled into the surface layer within the subsequent six months after their release. The floats remaining within the subsurface layer were likely transported further south by the current, offshore by westward-propagating eddies or equatorward by the deeper part of the surface coastal current.

Offshore wind power simulation by using WRF in the central coast of Chile

This paper presents the first estimate of offshore wind power potential for the central coast of Chile. For this purpose, wind speed data from in-situ stations and ERA-Interim reanalysis were used to simulate wind fields at regional level by means of the Weather Research and Forecasting (WRF) model. Wind field simulations were performed at different heights (20, 30, 40 and 140 m.a.s.l.) and a spatial resolution of 3 × 3 km for the period from February 1, 2006 to January 31, 2007, which comprised the entire series of in-situ data available. The results show an RMSE and r2 of 2.2 m s−1 and 0.55 respectively for the three heights simulated as compared to in-situ data. Based on the simulated wind data, the wind power for the study area was estimated at ∼1000 W m−2 at a height of 140 m.a.s.l. For a typical wind turbine of 8 MW generator, the estimated capacity factor exceeds 40%, with an average annual generation of ∼30 GWh. Offshore wind power in Chile is an emerging renewable energy source that is as yet still under-developed, these estimates help to fill in some of the gaps in our knowledge about Chile's true renewable energy potential.

Variability of 14C reservoir age and air–sea flux of CO2 in the Peru–Chile upwelling region during the past 12,000 years

The variability of radiocarbon marine reservoir age through time and space limits the accuracy of chronologies in marine paleo-environmental archives. We report here new radiocarbon reservoir ages (ΔR) from the central coast of Chile (~32°S) for the Holocene period and compare these values to existing reservoir age reconstructions from southern Peru and northern Chile. Late Holocene ΔR values show little variability from central Chile to Peru. Prior to 6000calyr BP, however, ΔR values were markedly increased in southern Peru and northern Chile, while similar or slightly lower-than-modern ΔR values were observed in central Chile. This extended dataset suggests that the early Holocene was characterized by a substantial increase in the latitudinal gradient of marine reservoir age between central and northern Chile. This change in the marine reservoir ages indicates that the early Holocene air–sea flux of CO2 could have been up to five times more intense than in the late Holocene in the Peruvian upwelling, while slightly reduced in central Chile. Our results show that oceanic circulation changes in the Humboldt system during the Holocene have substantially modified the air–sea carbon flux in this region.