Implication of Shoreline and Nearshore Morphological Changes on Sediment Budget of Wave-Dominated Chennai Beach, India

The study examines the shoreline (1990-2019) and nearshore morphological changes (seasonal) to understand the littoral drift and sediment budget variability. Shoreline change rate depicts erosion (-0.06 m/yr) in the northern sector and accretion (+0.12 m/yr) in the southern sector. Seasonal nearshore morphological changes from non-monsoon to monsoon period signifies net erosion (-1.8x10^4 m^3 ) in northern sector and net accretion (+2.5x10^4 m^3) in the southern sector. Although the lost sediment during monsoon is regained in non-monsoon period, the quantity of sediment gain is reduced in areas with human interventions. The results of the investigation depict the dominance of littoral drift towards north from February to October, when wave approach from east-southeast to south-southeast direction and southwards from November to January when the wave direction was from east-northeast to east-southeast. The net longshore sediment transport rate estimated during the study period was 2.6x10^5 m^3/year in the northern sector and 1.5x10^5 m^3/year in the southern sector with higher rate attributed to monsoon than the non-monsoon. Sediment budget results in deciphering the causes of erosion (-1.27×10^4 m^3/yr) in northern sector and accretion (3.91×10^4 m^3/yr) in southern sector in the wave-dominated Chennai beach.

Novedades sobre la construcción del foro de Libisosa: noticia preliminar de las últimas intervenciones arqueológicas

The following paper offers a small preview of the results of the archaeological studies carried out in the 2019 and 2020 campaigns in the Northern sector of the Roman forum of Libisosa (Lezuza, Albacete, Spain), a coordinated effort aiming at its consolidation

SARMATIAN BURIALS EXCAVATED BY DMYTRO BEREZOVETS AT THE LOWER DNIEPER BASIN

During the campaigns of 1951 and 1953 Dmytro Berezovets excavated the Sarmatian graves near the Kut, Hrushivka and Marianske villages of Apostolovski district of Dnipropetrovsk region. These materials were published briefly, without typological and chronological definitions and analysis of the historical context, with illustrations of rather low quality. Moreover, there was some confusion and errors later made by some researchers, including the author, which have been replicated with each reference. Therefore, it is worthy to republish these materials from the standpoint of the current level of the Sarmatian studies in order to correct certain errors as well. Dmytro Berezovets has discovered the assemblages both of Early Sarmatian (Kut, Hrushivka, Maryanske, barrow 3, grave 4) and Middle Sarmatian Age (Marianske, barroow 5, graves 5—7; barrow 5, grave 6; barrow 6, grave 14) according to traditional chronology. All Sarmatian burials under study were the secondary graves in the Bronze Age mounds and Scythian ones. The skeletons lied supine, with their heads directed to Northern sector. Among the grave goods are the Roman and Sarmatiam pottery, simple bronze adornment, cornelian, jade and glass beads, bronze mirror, bone ritual spoon etc. The Early Sarmatian assemblages discovered by Dmytro Berezovets are dated to the late 2nd—1st century BC, the Middle Sarmatiam ones to the 1st—2nd centuries AD. The identical funeral rite of the graves of different date near Marianske once again confirms the validity of the periodization proposed by me in due time, according to which all the graves under study belong to different phases of the first period (phase A2 — Kut, Hrushivka, Marianske, barrow 3, grave 4; phase B — Marianske, barrow 3, graves 5—7; barrow 5, grave 6; barrow 6, grave 14).

Southern Ocean latitudinal gradients of cloud condensation nuclei

The Southern Ocean region is one of the most pristine in the world and serves as an important proxy for the pre-industrial atmosphere. Improving our understanding of the natural processes in this region is likely to result in the largest reductions in the uncertainty of climate and earth system models. While remoteness from anthropogenic and continental sources is responsible for its clean atmosphere, this also results in the dearth of atmospheric observations in the region. Here we present a statistical summary of the latitudinal gradient of aerosol (condensation nuclei larger than 10 nm, CN10) and cloud condensation nuclei (CCN at various supersaturations) concentrations obtained from five voyages spanning the Southern Ocean between Australia and Antarctica from late spring to early autumn (October to March) of the 2017/18 austral seasons. Three main regions of influence were identified: the northern sector (40–45∘ S), where continental and anthropogenic sources coexisted with background marine aerosol populations; the mid-latitude sector (45–65∘ S), where the aerosol populations reflected a mixture of biogenic and sea-salt aerosol; and the southern sector (65–70∘ S), south of the atmospheric polar front, where sea-salt aerosol concentrations were greatly reduced and aerosol populations were primarily biologically derived sulfur species with a significant history in the Antarctic free troposphere. The northern sector showed the highest number concentrations with median (25th to 75th percentiles) CN10 and CCN0.5 concentrations of 681 (388–839) cm−3 and 322 (105–443) cm−3, respectively. Concentrations in the mid-latitudes were typically around 350 cm−3 and 160 cm−3 for CN10 and CCN0.5, respectively. In the southern sector, concentrations rose markedly, reaching 447 (298–446) cm−3 and 232 (186–271) cm−3 for CN10 and CCN0.5, respectively. The aerosol composition in this sector was marked by a distinct drop in sea salt and increase in both sulfate fraction and absolute concentrations, resulting in a substantially higher CCN0.5/CN10 activation ratio of 0.8 compared to around 0.4 for mid-latitudes. Long-term measurements at land-based research stations surrounding the Southern Ocean were found to be good representations at their respective latitudes; however this study highlighted the need for more long-term measurements in the region. CCN observations at Cape Grim (40∘39′ S) corresponded with CCN measurements from northern and mid-latitude sectors, while CN10 observations only corresponded with observations from the northern sector. Measurements from a simultaneous 2-year campaign at Macquarie Island (54∘30′ S) were found to represent all aerosol species well. The southernmost latitudes differed significantly from both of these stations, and previous work suggests that Antarctic stations on the East Antarctic coastline do not represent the East Antarctic sea-ice latitudes well. Further measurements are needed to capture the long-term, seasonal and longitudinal variability in aerosol processes across the Southern Ocean.

Benthic polychaetes collected in the III Expedición “Admiral Padilla” Austral Summer 2016-2017, to the north of the Antarctic Peninsula

Polychaeta represents the most diverse class in the phylum Annelida, mainly composed by marine organisms, with some terrestrial and freshwater representatives. The present work records the information of the benthic polychaetes, which were collected in four stations in the northern sector of the Antarctic Peninsula, in the III Expedición “Admiral Padilla” verano austral 2016-2017, including taxonomy, relative abundance and frequency of occurrence by family. A total of 326 individuals were quantified, distributed in 12 families: Apistobranchidae, Capitellidae, Cirratulidae, Dorvilleidae, Maldanidae, Nereididae, Orbiniidae, Paraonidae, Serpulidae, Sigalionidae, Spionidae and Syllidae, and the suborder Terebelliformia. Cirratulidae, and Paraonidae were predominant in terms of abundance and frequency. A previous taxonomic analysis has shown morphological variability in the families Cirratulidae, Dorvilleidae, Maldanidae, Paraonidae and Syllidae, and the suborder Terebelliformia. The samples were processed, and deposited at the Marine Natural History Museum of Colombia (MHNMC) – Makuriwa from the Marine and Coastal Research Institute “José Benito Vives de Andréis - Invemar.

Epipelagic euphausiids assemblage in the Gerlache Strait (Antarctic Peninsula) during January 2015

The spatial distribution of the epipelagic Euphausiids was investigated during the first Colombian Scientific Expedition to Antarctica “Expedición Caldas” in the Gerlache Strait during the austral summer of 2015. Surface zooplankton was collected at 20 oceanographic stations with a simple conical net of 0.6 m in diameter mouth and 200 µm of mesh net. Four euphausiid species were collected in 70 % of the sampling stations: Euphausia crystallorophias Holt and Tattersall 1906, Euphausia superba Dana 1850, Thysanoessa sp. and Thysanoessa macrura Sars 1883. Euphausia crystallorophias was the most abundant species with maximum density of 818 ind 1000 m-3 associated with the entrance of the Wilhelmina Bay, in the central area of the Gerlache Strait. The northern and southern sectors of the strait had significant differences in surface temperature and salinity associated with significant differences in the composition of the euphausiid species assemblages between both sectors. Although E. crystallorophias was the numerically dominant euphausiid species in the Gerlache Strait, E. superba was mostly distributed in the northern sector while Thysanoessa sp. was only distributed in the southern sector.

Benthic polychaete off Tanintharyi Island, Myeik Archipelago

The survey examined shallow to deep-sea benthic data on benthic fauna from the Myanmar coastal region's northern sector. Benthic samples were collected from 17 stations (26-1500m depth) off Taninthayi Island during the Mayanmar ecosystem survey of the R/V Dr. Fridtjof Nansen Research Vessel. Polychaete (25 taxa in total) had a higher proportion than other groups of benthic fauna. The range of species diversity and evenness were insignificantly different, but species richness differed. The highest species diversity, species evenness, and richness were showed in shallow areas (26 m depth). Keywords: Diversity indices, Polychaetes, Taninthayi Island, Myeik Archipelago.