Arqueologías del ¿Futuro? : Cartografía estética aplicada a territorios específicos

Los Territorios Específicos condicionados socioambiental y/o físicoculturalmente son sistematizados en base a sus cualidades éticas y estéticas en su sentido filosófico y formal respectivamente. Los mismos surgen como entidades orgánicamente integradas a nivel de las prácticas culturales en función de una performatividad autopoiética con gradientes y resonancias ampliamente debatidas académicamente y/o, a través de producciones específicas de las artes visuales contemporáneas. La Cartografía Estética propuesta se conforma de un corpus de obras plásticas y teóricas que, en la trayectoria expositiva abordada para este estudio, conforman una constelación de ejes temáticos y procedimentales en vinculación a los modos de producción en artes visuales. Estos nódulos o modos de hacer en artes visuales, se integran en una fascinante e interesante red epistemológica que, a la luz de las obras de arte seleccionadas son transparentadas no sólo en su complejidad epistémica sino que también son confrontados a interesantes gestos y guiños visuales a modo de cita y figuras conceptuales que en sentido moebiano remisionan formas de inscripción de obra y de la legibilidad de la misma conformando un alfabeto visual contemporáneo indispensable a la hora de pensar y entender la producción artística del último siglo en general y de las artes visuales latinoamericanas y chilenas en particular, todas ellas conforman una panorámica global en lo que hoy se conoce y divulga como arte actual. La unidad espacial abordada como Territorios Específicos se constituyen críticamente por conformar zonas y áreas marginales, espacios residuales y limítrofes, a la vez que contenedores y contenido de resistencia asistémica facilitado por un desinterés administrativo consecuente a su calidad de margen residual naturalizado y sus contenidos subyacentes. Metodológicamente, esta investigación ha sido cuidadosamente sistematizada a partir de herramientas de análisis y medición provenientes de las ciencias sociales y otras más afín a las de la ingeniería como arquitectura y urbanismo y de otras ciencias fronterizas de las biofísicas como la arqueología, etnografía y antropología, adaptadas todas a un interesantísimo protocolo instrumental replicable para las artes visuales. Este compendio procedimental comprende acciones de arte de sitio específico realizadas en una franja costera de 30 kilómetros que abarca desde la ciudad de Valdivia hasta 'La Reserva de Curiñanco' en la recientemente inaugurada XIV Región de Los Ríos en Chile. Estas acciones son confrontadas y tensionadas tanto a nivel de la crítica especializada como de sus afluentes epistemológicos colindantes con las ciencias humanas, donde, este corpus de obra contemporáneas, curatorías, proyectos de sitio y debates especializados, aportan considerablemente a la construcción de futuros posibles no solo de las artes visuales en particular y de las ciencias humanas en general, sino que además conllevan un debate ineludible para el desafío implicado en el debate territorio/globalización

Valorización de la naturaleza y disputa por el territorio en la Provincia de Santa Cruz

Desde los inicios de la colonización europea, la historia de la Patagonia es la trayectoria de la ocupación para la puesta en valor de la riqueza de sus bienes naturales en el suelo, subsuelo y en su extenso litoral marítimo. Asentados primero en la explotación del ovino, luego del petróleo, el gas y el carbón y recientemente de la pesca, la minería metalífera y el turismo internacional, los territorios de las actuales provincias de Santa Cruz, del Chubut y de Tierra del Fuego, al igual que sus pares trasandinos de las regiones de Aysén y Magallanes, son espacios ricos en recursos. Para la puesta en valor de los territorios por parte del capital, hacen falta dos condiciones básicas: la existencia de bienes naturales y la presencia de fuerza de trabajo, las cuales, dependiendo de la actividad, pueden o no estar presentes. En algunos casos, se hace necesario adecuar estos espacios mediante equipamientos e infraestructuras, la atracción de trabajadores de diversa calificación y la presencia estatal, en un doble proceso de expansión geográfica y acumulación por desposesión que asegure la valorización en general. En estos territorios, periféricos desde el punto de vista espacial, cada proceso de valorización particular exigió una combinación de apropiación, habilitación y organización del territorio específicas. En el presente artículo se apunta, en primer lugar, a presentar sintéticamente los procesos históricos de valorización de la naturaleza de la región, para luego analizar la actual situación del proceso en el territorio y los conflictos resultantes. En una segunda parte, teniendo en cuenta las tendencias mundiales de alta demanda de bienes naturales, se expondrán los escenarios futuros más probables en caso de acentuarse el actual modelo extractivo y rentista

Patagonia, naturaleza y territorios

La Patagonia es desde fines del siglo XIX espacio de provisión de recursos de la naturaleza. Las políticas nacionales y provinciales para la región llevaron a significativos procesos de desarrollo geográfico desigual, con espacios en general muy poco poblados. Actualmente pervive y se acentúa el modelo primario-exportador de la mano del neoextractivismo, con el Estado buscando participar en el reparto de la renta por la explotación del subsuelo, suelo y litoral marítimo. En el articulo se analiza el lugar de la Patagonia en el actual escenario de fin del ciclo de los commodities, de crisis de hegemonía y de emergencia de un mundo multipolar a la par de la convergencia de las pautas de consumo material, que estarían llevando en su conjunto a una produndización de la crisis socio-ecológica y a la aceleración de la disputa por la naturaleza y el sentido del territorio

Análisis de usos normativos y su vinculación con áreas en riesgo de inundación. El caso de 23 partidos del litoral bonaerense

El presente trabajo se basa en un análisis de la normativa dispuesta en materia de ordenamiento territorial y usos de suelo de los 23 partidos de la cuenca Parano- Platense que conforman el área de estudio del proyecto en el cual se encuadra el mismo1, considerando el tratamiento específico de áreas afectadas y prevención de las inundaciones. Para ello se ha tenido en cuenta: a) el análisis de la evolución de la regulación del Estado en la ocupación del suelo para el Gran Buenos Aires; b) el registro actualizado de ordenanzas en materia de ordenamiento territorial y Usos del Suelo convalidadas por Poder Ejecutivo (PE) (Nº de ordenanza y el Nº de Decreto del Poder Ejecutivo de convalidación; c) la norma específica (Nº de ordenanza / Nº de decreto del PE) por municipio / por contenido. Los datos para llevar a cabo el estudio de usos de suelo normativos se obtuvieron del nuevo Mapa Interactivo de Ordenamiento Territorial de la Provincia de Buenos Aires, que fue generado por el Ministerio de Gobierno de la Provincia de Buenos Aires, Subsecretaría de Asuntos Municipales. El análisis de la normativa vigente de cada uno de los 23 partidos que abarcan el ámbito de estudio nos permitirá definir estrategias futuras de intervención, las cuales actuarán como instrumento en materia de ordenamiento territorial desde la gestión de cada municipio.

Oxygen isotope and Mg/Ca record of planktonic foraminifera of sediment core MD01-2390

Changes in the local freshwater budget over the last 22,000 years have been estimated from a sediment core located in the southern South China Sea (SCS) using a combined approach of Mg/Ca and oxygen isotopes on the planktonic foraminifera Globigerinoides ruber (white) sensu stricto (s.s.). Core MD01-2390 (06°28,12N, 113°24,56E; water depth 1591 m) is located near the glacial paleo-river mouths of the Baram, Rajang and North Sunda/Molengraaff Rivers that drained the exposed Sunda Shelf. The delta18Oseawater record reveals lower average values (-0.96±0.18 per mil) during the Last Glacial Maximum (LGM) when compared with modern values (-0.54±0.18 per mil). Low salinity during the LGM is interpreted to reflect a higher freshwater contribution due to a greater proximity of the core site to the mouths of the Baram, Rajang and North Sunda/Molengraaff Rivers at that time. A general deglacial increasing trend in salinity due to the progressive landward displacement of the coastline during deglacial shelf flooding is punctuated by several short-term shifts towards higher and lower salinity that are likely related to abrupt changes in the intensity of the East Asian summer monsoon. Thus, the deglacial delta18Oseawater changes reflect the combined effects of sea-level-induced environmental changes on the shelf (e.g. phases of retreat and breakdown of the shelf drainage systems) and East Asian monsoon climate change. Lower salinity than at present during the Early Holocene may be attributed to an increase in summer monsoonal precipitation that is corroborated by previous marine and terrestrial studies that report a Preboreal-Early Holocene monsoon optimum in the Asian monsoon region.

Geologic-hydrologic setting and surface sedimentology in the Persian Gulf

1. Morphology and sedimentation The deepest parts of the Persian Gulf lie off the Iranian coast. Several swells separate the Persian Gulf into the Western Basin, the Central Basin and the Strait of Hormuz, which leads without noticeable morphological interruption onto the Biaban Shelf; the latter gradually drops off towards the continental slope, which itself has a strongly subdivided morphology. The sediment distribution in the Western Basin runs parallel to the basin's axis to a depth of 50 -60 m. This is caused by the shallow and uniform slope of the Iranian coast into the Western Basin, by clear exposure of the area to the Shamal-Winds and by tidal currents parallel to the basin's axis. Most other parameters also show isolines parallel to the coast line. Data from the sediment analyses show a net transport which extends out along the Central Swell: coarse fraction > 63 µ, total carbonate content, carbonate in fine fractions < 2 µ, 2-6 µ and 20-63 µ, calcite-aragonite ratios in the fine fractions 2-6 µ and 20-63 µ and quartz-dolomite ratios in fine fraction 2-6 µ. At least the uppermost 10-40 m of this sediment is late Holocene. This implies sedimentation rates of several meters per 1000 years. The slope from the Iranian coast into the Central Basin (max. depth 100 m) is generally steeper, with interspersed islands and flats. Both facts tend to disturb a sediment dustribition parallel to the basin's axis over extensive areas and may preclude any such trend from being detected by the methods and sample net used. The spatial distribution of the coarse fraction, however, seems to indicate sediment transport at greater water depths perpendicular to the basin's long axis and along the steepest gradients well into the Central Basin. The flats of the Central Basin have a sediment cover distinctly different from those of the deeper basin areas. Characteristic parameters are the extremely high percentages of coarse grained sediments, total content of carbonate CO2 over 40, low total organic carbon content, (however values are high if calculated on the basis of the < 63 µ fraction), low total N-content, and low C/N ratios. These characteristics probably result from the absence of any terrigenous material being brought in as well as from exposure to wave action. Finest terrigenous material is deposited in the innermost protected part of the Hormuz Bay. In the deep channel cut into the Biaban Shelf which carries the Persian Gulf out-flow water to the Indian Ocean, no fine grained sediment is deposited as shown by grain size data. 2. Geographic settings and sedimentation Flat lands border the Arabian coast of the Persian Gulf except for the Oman region. The high and steep Zagros Mountains form the Iranian coastline. Flat topography in combination with generally low precipitation precludes fluviatile sediment being added from the South. Inorganic and biogenic carbonates accumulating under low sedimentation rates are dominant on the shallow Arabic Shelf and the slopes into the Western and Central Basins. The fluviatile sediment brought in from the Iranian side, however decisively determine the composition of the Holocene sediment cover in the Persian Gulf and on the Biaban Shelf. Holocene sediments extend 20-30 km seaward into the Western Basin and about 25 km on to the Biaban Shelf. As mentioned before, sedimentation rates are of several meters/1000 years. The rocks exposed in the hinterland influence the sediments. According to our data the Redbeds of the Zagros Mountains determine the colour of the very fine grained sediments near the Iranian Coast of the Persian Gulf. To the West of Hormuz, addition of carbonate minerals is particularly high. Dolomite and protodolomite, deposited only in this area, as well as palygorskite, have proven to be excellent trace minerals. To the East of Hormuz, the supply of terrigenous carbonates is considerably lower. Clay minerals appear to bring in inorganically bound nitrogen thus lowering the C/N ratio in these sediments especially off river mouths. 3. Climate and sedimentation The Persian Gulf is located in a climatically arid region. This directly affects sedimentation through increased wind action and the infrequent but heavy rainfalls which cause flash floods. Such flash floods could be responsible for transporting sedheats into the Central Basin in a direction perpendicular to the Gulf's axis. Eolian influx is difficult to asses from our data; however, it probably is of minor importance from the Iranian side and may add, at the most, a few centimeters of fine sediment per 1000 years. 4. Hydrology and sedimentation High water temperatures favor inorganic carbonate precipitation in southern margin of the Gulf, and probably on the flats, as well as biogenic carbonate production in general. High evaporation plus low water inflow through rivers and precipitation cause a circulation pattern that is typical for epicontinental seas within the arid climate region. Surface water flows in from the adjoining ocean, in this case the Indian Ocean and sinks to the bottom of the Persian Gulf mainly in the northern part of the Western Basin, on the "Mesopotamischer Flachschelf" ard probably in the area of the "Arabischer Flachschelf". This sinking water continually rejuvenates the bottom out-flow water. The inflowing surface water from the Indian Ocean brings organic matter into the Persian Gulf, additional nutrients are added by the "fresh" upwelling waters of the Gulf of Oman. Both nutrients and organic matter diminish very rapidly as the water moves into the Persian Gulf. This depletion of nutrients and organic matter is the reasonfor generally low organic carbon contents of the Persian Gulf sediments. The Central Swell represents a distinct boundary, to the west of which the organic carbon content are lower than to the east when sediment samples of similar grain size distribution are compared. The outflow carries well oxygenated water over the bottom of the Persian Gulf and the resulting oxidation further decreases the content of organic matter. In the Masandam-Channel and in the Biaban-Shelf channel, the outflowing water prevents deposition of fine material and transports sediment particles well beyond the shelf margin. The outflowing water remains at a depth of 200-300 m depending on its density and releases ist suspending sediment load to the ocean floor, irrespectative of the bottom morphology. This is reflected in several parameters in which the sediments from beneath the outflow differ from nearby sediments not affected by the outflowing water. High carbonate content of total samples and of the individual size fraction as well as high aragonite and dolomite contents of individual size fractions characterize the sediment beneath the outflowing water. The tidal currents, which avt more or less parallel to the Gulf's axis, favor mixing of the water masses, they rework sediments at velocities reported here. This fact enlarges to a certain degree the extent of our interfaces which are based on only a few sample points (Persian Gulf and Biaban Shelf one sample per 620 km**2, continental slope one sample per 1000 km**2). The water on the continental slope shows and oxygen minimum at 200-1200 m which favors preservation of organically-bound carbon in the sediment. The low pH-values may even permit dissolution of carbonate minerals.

Colored dissolved organic matter (cDOM) absorption measurements in terrestrial water objects of Yamal, Yavai and Gydan Peninsula

The datasets present measurements of cDOM absorption in lakes, rivers and streams of Yamal and Gydan Peninsula area during the summer periods from 2012-2014 and 2016. In summer seasons of 2012 - 2013 water samples was collected during "Yamal-Arctic" Expedition. All of the research areas were located near the coastline of Yamal, Yavay, and Gydan Peninsula and Bely Island. In 2012 water samples from rivers, lakes and streams were taken near New Port, Cape Kamenny and Tambey settlements and in basins (water catchments) of the Sabetta, Seyakha, Yuribey (Baydaratskaya Bay, Gydan Peninsula) and Mongocheyakha rivers. In 2013 water samples from rivers, lakes and streams were taken in the Yavai Peninsula, Yayne Vong bay and in the basins (water catchments) of the Sabetta, Mongocheyakha and Yuribey (Gydan Peninsula) rivers. In 2014 lakes were sampled in the Erkuta River basin, south of Yamal Peninsula. In 2016 lakes and rivers were sampled it the Erkuta River basin and Polar Ural area. cDOM is operationally defined by the chosen filter pore size. Samples have been consistently filtrated through 0.7 µm pore size glas fibre filters. cDOM filtrates have been stored in darkness and have been measured after the expedition using the dual-beam Specord200 laboratory spectrometer (Jena Analytik) at the Otto Schmidt Laboratory OSL, Arctic and Antarctic Research Institute, St. Petersburg, Russia. The OSL cDOM protocol (Heim and Roessler, 2016) prescribes 3 Absorbance (A) measurements per sample from UV to 750 nm against ultra-pure water. The absorption coefficient, a, is calculated by a = 2.303A/L, where L is the pathlength of the cuvette [m], and the factor 2.303 converts log10 to loge. The output of the calculation is a continuous spectrum of a. The cDOM a spectra are used to determine the exponential slope value for specific wavelength ranges, S by fitting the data between min and max wavelength to an exponential function. We provide cDOM absorption coefficients for the wavelengths 254, 260, 350, 375, 400, 412, 440, 443 nm [1/m] and Slope values for three different UV, VIS, wavelength ranges: 275 to 295 nm, 350 to 400 nm, 300 to 500 nm [1/m]. All data were carried out by scientists from Arctic and Antarctic Research Institute and Saint Petersburg State University of Russia during "Yamal-Arctic" expeditions in 2012-2013, RFBR project No 14-04-10065 in 2014, No 14-05-00787 in 2016.

Images of a groundwater flow system in Nicaragua

Conceptualization of groundwater flow systems is necessary for water resources planning. Geophysical, hydrochemical and isotopic characterization methods were used to investigate the groundwater flow system of a multi-layer fractured sedimentary aquifer along the coastline in Southwestern Nicaragua. A geologic survey was performed along the 46 km2 catchment. Electrical resistivity tomography (ERT) was applied along a 4.4 km transect parallel to the main river channel to identify fractures and determine aquifer geometry. Additionally, three cross sections in the lower catchment and two in hillslopes of the upper part of the catchment were surveyed using ERT. Stable water isotopes, chloride and silica were analyzed for springs, river, wells and piezometers samples during the dry and wet season of 2012. Indication of moisture recycling was found although the identification of the source areas needs further investigation. The upper-middle catchment area is formed by fractured shale/limestone on top of compact sandstone. The lower catchment area is comprised of an alluvial unit of about 15 m thickness overlaying a fractured shale unit. Two major groundwater flow systems were identified: one deep in the shale unit, recharged in the upper-middle catchment area; and one shallow, flowing in the alluvium unit and recharged locally in the lower catchment area. Recharged precipitation displaces older groundwater along the catchment, in a piston flow mechanism. Geophysical methods in combination with hydrochemical and isotopic tracers provide information over different scales and resolutions, which allow an integrated analysis of groundwater flow systems. This approach provides integrated surface and subsurface information where remoteness, accessibility, and costs prohibit installation of groundwater monitoring networks.

Classified Adélie penguin colonies from Landsat data

Breeding distribution of the Adelie penguin, Pygoscelis adeliae, was surveyed with Landsat-7 Enhanced Thematic Mapper Plus (ETM+) data along the coastline of Antarctica, an area covering approximately 330° of longitude. An algorithm was designed to minimize the radiometric contribution from exogenous sources and to retrieve Adelie penguin colony location and spatial extent from the ETM+ data. In all, 9143 individual pixels were classified as belonging to an Adelie penguin colony class out of the entire dataset of 195 ETM+ scenes, where the dimension of each pixel is 30 m by 30 m, and each scene is approximately 180 km by 180 km. Pixel clustering identified a total of 187 individual Adelie penguin colonies, ranging in size from a single pixel (900 m**2) to a maximum of 875 pixels (0.788 km**2). Colony retrievals have a very low error of commission, on the order of 1 percent or less, and the error of omission was estimated to be 2.9 percent by population based on comparisons with direct observations from surveys across east Antarctica. Thus, the Landsat retrievals can successfully locate Adelie penguin colonies that account for ~97 percent of a regional population. Geographic coordinates and the spatial extent of each colony retrieved from the Landsat data are available publically. Regional analysis found several areas where the Landsat retrievals suggest populations that are significantly larger than published estimates. Six Adelie penguin colonies were found that are believed to be unreported in the literature.

Measurements of seawater and aerosol particles during POLARSTERN cruise ANT-XXVII/4

An analytical method for the determination of the alpha dicarbonyls glyoxal (GLY) and methylglyoxal (MGLY) from seawater and marine aerosol particles is presented. The method is based on derivatization with o-(2,3,4,5,6-Pentafluorobenzyl)-hydroxylamine (PFBHA) reagent, solvent extraction and GC-MS (SIM) analysis. The method showed good precision (RSD < 10%), sensitivity (detection limits in the low ng/l range), and accuracy (good agreement between external calibration and standard addition). The method was applied to determine GLY and MGLY in oceanic water sampled during the Polarstern cruise ANT XXVII/4 from Capetown to Bremerhaven in spring 2011. GLY and MGLY were determined in the sea surface microlayer (SML) of the ocean and corresponding bulk water (BW) with average concentrations of 228 ng/l (GLY) and 196 ng/l (MGLY). The results show a significant enrichment (factor of 4) of GLY and MGLY in the SML. Furthermore, marine aerosol particles (PM1) were sampled during the cruise and analyzed for GLY (average concentration 0.19 ng/m**3) and MGLY (average concentration 0.15 ng/m**3). On aerosol particles, both carbonyls show a very good correlation with oxalate, supporting the idea of a secondary formation of oxalic acid via GLY and MGLY. Concentrations of GLY and MGLY in seawater and on aerosol particles were correlated to environmental parameters such as global radiation, temperature, distance to the coastline and biological activity. There are slight hints for a photochemical production of GLY and MGLY in the SML (significant enrichment in the SML, higher enrichment at higher temperature). However, a clear connection of GLY and MGLY to global radiation as well as to biological activity cannot be concluded from the data. A slight correlation between GLY and MGLY in the SML and in aerosol particles could be a hint for interactions, in particular of GLY, between seawater and the atmosphere.

Pollen distribution in marine sediment samples along the south-western African coast

The distribution of pollen in marine sediments is used to reconstruct pathways of terrigenous input to the oceans and provides a record of vegetation change on adjacent continents. The wind transport routes of aeolian pollen is comprehensively illustrated by clusters of trajectories. Isobaric, 4-day backward trajectories are calculated using the modelled wind-field of ECHAM3, and are clustered on a seasonal basis to estimate the main pathways of aeolian particles to sites of marine cores in the south-eastern Atlantic. Trajectories and clusters based on the modelled wind-field of the Last Glacial Maximum hardly differ from those of the present-day. Trajectory clusters show three regional, and two seasonal patterns, determining the pathways of aeolian pollen transport into the south-eastern Atlantic ocean. Mainly, transport out of the continent occurs during austral fall and winter, when easterly and south-easterly winds prevail. South of 25°S, winds blow mostly from the west and southwest, and aeolian terrestrial input is very low. Generally, a good latitudinal correspondence exists between the distribution patterns of pollen in marine surface sediments and the occurrence of the source plants on the adjacent continent. The northern Angola Basin receives pollen and spores from the Congolian and Zambezian forests mainly through river discharge. The Zambezian vegetation zone is the main source area for wind-blown pollen in sediments of the Angola Basin, while the semi-desert and desert areas are the main sources for pollen in sediments of the Walvis Basin and on the Walvis Ridge. A transect of six marine pollen records along the south-western African coast indicates considerable changes in the vegetation of southern Africa between glacial and interglacial periods. Important changes in the vegetation are the decline of forests in equatorial Africa and the north of southern Africa and a northward shift of winter rain vegetation along the western escarpment.

Carbon sources in the North Sea evaluated by means of carbon isotope tracers

A multitracer approach is applied to assess the impact of boundary fluxes (e.g., benthic input from sedi- ments or lateral inputs from the coastline) on the acid-base buffering capacity, and overall biogeochemistry, of the North Sea. Analyses of both basin-wide observations in the North Sea and transects through tidal basins at the North-Frisian coastline, reveal that surface distributions of the d13C signature of dissolved inorganic carbon (DIC) are predominantly controlled by a balance between biological production and respiration. In particular, variability in metabolic DIC throughout stations in the well-mixed southern North Sea indi- cates the presence of an external carbon source, which is traced to the European continental coastline using naturally occurring radium isotopes (224Ra and 228Ra). 228Ra is also shown to be a highly effective tracer of North Sea total alkalinity (AT) compared to the more conventional use of salinity. Coastal inputs of meta- bolic DIC and AT are calculated on a basin-wide scale, and ratios of these inputs suggest denitrification as a primary metabolic pathway for their formation. The AT input paralleling the metabolic DIC release prevents a significant decline in pH as compared to aerobic (i.e., unbuffered) release of metabolic DIC. Finally, long- term pH trends mimic those of riverine nitrate loading, highlighting the importance of coastal AT production via denitrification in regulating pH in the southern North Sea.

Coastal retreat at the northern Baltic Sea between Flensburg and Travemünde

Long-term surveys of the coast bordering the western Baltic Sea in Schleswig-Holstein yielded extensive information over the retreat and condition of active cliffs. 181 cliffs with a total length of 148 km are present along the 55 km coastline including Fehmarn lsland and the Schlei Fjord. Depending on their temporal and spatial evolution, and geomorphological stability, the cliffs are subdivided in three separate classes - actively retreating escarpments, cliff Segments with potential for retreat and stable cliffs. 85 sections of the coastline with a total length of 59 km are classified as ,,active cliffs" that are undergoing retreat through natural erosion, collapse, and disintegration.

Macrozoobenthos abundance of the intertidal zone of a sandy beach at the Island Algodoal-Maiandeua, Pará, Brazil

The present study describes quantitatively the macrozoobenthic community structure in intertidal of the Island Algodoal-Maiandeua in the Northern Brazilian state of Pará, which is part of a protected area since 1990. Samples of the epi-and endomacrobenthos of the unconsolidated substrate were collected in October 2012, using a PVC cylindrical corer with a surface area of 60 square centimeter at a depth of 30 cm, along three transects located perpendicular to the coastline, separated by intervals of 50 m. Collected material was sieved on a 1 mm mesh, specimens were fixed in 4% formaldehyde buffered with borax. In Tropical Benthic Ecology laboratory macroinvertebrates were washed with 70% alcohol and afterwards identified with a stereomicroscope and specific literature.

Coastal erosion dynamics and storm characteristics of Bykovsky Peninsula

This study investigates the rate of erosion during the 1951-2006 period on the Bykovsky Peninsula, located north-east of the harbour town of Tiksi, north Siberia. Its coastline, which is characterized by the presence of ice-rich sediment (Ice Complex) and the vicinity of the Lena River Delta, retreated at a mean rate of 0.59 m/yr between 1951 and 2006. Total erosion ranged from 434 m of erosion to 92 m of accretion during these 56 years and exhibited large variability (sigma = 45.4). Ninety-seven percent of the rates observed were less than 2 m/yr and 81.6% were less than 1 m/yr. No significant trend in erosion could be recorded despite the study of five temporal subperiods within 1951-2006. Erosion modes and rates actually appear to be strongly dependant on the nature of the backshore material, erosion being stronger along low-lying coastal stretches affected by past or current thermokarst activity. The juxtaposition of wind records monitored at the town of Tiksi and erosion records yielded no significant relationship despite strong record amplitude for both data sets. We explain this poor relationship by the only rough incorporation of sea-ice cover in our storm extraction algorithm, the use of land-based wind records vs. offshore winds, the proximity of the peninsula to the Lena River Delta freshwater and sediment plume and the local topographical constraints on wave development.