Observations of rotational motion in prominences

The writer reports some recent observations carried out with the McMath Solar Telescope, which can be interpreted as due to rotational motions in prominences. Kitt Peak National Observatory Contribution No. 454. Visiting Astronomer to the Solar Division, Kitt Peak National Observatory, operated by the Association of Universities for Research in Astronomy, Inc. under contract with the National Science Foundation.     

Patterns and Levels of Organochlorines (DDTs, PCBs, non-ortho PCBs and PCDD/Fs) in Male Harbour Porpoises (Phocoena phocoena) from the Baltic Sea, the Kattegat-Skagerrak Seas and the West Coast of Norway

Patterns and levels of chlorinated aromatic contaminants (DDTs, PCBs, non-ortho PCBs and PCDD/Fs) in blubber tissue were compared among six sample groups of male harbour porpoises (Phocoena phocoena) from the Baltic Sea, the Kattegat-Skagerrak Seas and the west coast of Norway. A principal component and classification analysis showed that mature harbour porpoises from the Baltic had significantly different contaminant patterns than animals from the Kattegat-Skagerrak and Norway. ANOVAs showed that mature porpoises from the Baltic had higher levels of ΣPCB and several individual PCBs and PCDD/Fs than the Kattegat-Skagerrak and the Norwegian samples and higher ΣDDT than the Norwegian. A comparison between immature porpoises showed that Baltic animals had higher levels of ΣPCDD/F than the corresponding sample from the Kattegat-Skagerrak. The levels of ΣDDT, ΣPCB and Σnon-ortho PCB were significantly higher in animals collected during 1978–81 compared to animals collected in 1988–90 indicating a temporal decline of these organochlorines in the Kattegat-Skagerrak Seas. The contaminant levels recorded in the Baltic Sea are a serious cause for concern and could have management implications for the already threatened harbour porpoises in this area.     

Are plasma satellites present among chromospheric lines?

From a study of the chromospheric lines listed by Pierce (1968, 1973) indications have been found that first-order plasma satellites appear sometimes as a pair of faint chromospheric emission lines in such places where forbidden lines, mainly of metals, should be located. Second-order satellites are indicated sometimes by an asymmetry in the emission wings of stronger lines, either with respect to intensity or with respect to distance from the line centre and, if so, with the remote wing of diffuse shape. Finally diffuse faint lines, appearing in somewhat greater distances from strong chromospheric lines, suggest the appearance sometimes of fourth-order plasma satellites. All the three types of satellites give electron densities of the order of 10¹² cm^?3. Traces of possible absorption satellites are found also for some of the lines in the solar spectrum. In this connection special attention is drawn to a few faint solar lines located near the wavelengths of corona emission lines. The observational evidence is discussed on the bases of recent theoretical research by Drawin and Truong-Bach (1982a, b).     

Basic physiological biomarkers in adult female perch (Perca fluviatilis) in a chronically polluted gradient in the Stockholm recipient (Sweden)

By measuring a battery of basic physiological biomarkers and the concentration of SigmaDDT in adult female perch (Perca fluviatilis), an assumed aquatic pollution gradient was confirmed, with the city of Stockholm (Sweden) as a point source of anthropogenic substances. The investigation included an upstream gradient, westwards through Lake M?laren (46 km), and a downstream gradient, eastwards through the Stockholm archipelago (84 km). The results indicated a severe pollution situation in central Stockholm, with poor health status of the perch: retarded growth, increased frequency of sexually immature females, low gonadosomatic index, and disturbed visceral fat metabolism. SigmaDDT, measured as a pollution indicator, was 10-28 times higher than the background in perch from the Baltic Proper. Besides the main gradient other sources of pollution also influenced the response pattern of the measured biomarkers. In particular, there were strong indications of pollution coming from the Baltic Sea.     

Sea-floor spreading and the early opening of the North Atlantic

We have examined available magnetic and gravity data bearing on the initiation of sea-floor spreading in the North Atlantic between Ireland and Newfoundland. The change in character of the magnetic field on the continental margin on either side of the Atlantic from a landward magnetic quiet zone to a seaward “noisy”, magnetic signature is postulated to be related to a change from continental to oceanic crust. Sea-floor spreading between Ireland and Newfoundland was initiated during the long normal geomagnetic polarity interval in the Late Cretaceous. Rockall Trough may have opened at this time. At the end of the normal polarity interval (Late Santonian) the ridge axis jumped westward to bypass Rockall Trough and the related offset initiated the Charlie Gibbs fracture zone.A reconstruction is presented for the relative position between North America and Europe prior to the initiation of sea-floor spreading in the Late Cretaceous.     

Dioxin-like compounds in HPLC-fractionated extracts of marine samples from the east and west coast of Sweden: Bioassay- and instrumentally-derived TCDD equivalents

Lipophilic extracts of sediment, settling particulate matter (SPM) and blue mussel (Mytilus edulis) samples, collected at coastal locations on the east and west coast of Sweden, were HPLC-separated into three fractions containing 1. monoaromatic/aliphatic, 2. diaromatic (e.g. polychlorinated biphenyls (PCBs), polychlorinated dibenzodioxins and polychlorinated dibenzofurans (PCDDs/Fs)), and 3. polyaromatic compounds (e.g. polycyclic aromatic hydrocarbons (PAHs)). The fractions were tested for dioxin-like effects using a sensitive bioassay, based on EROD-induction in cultured chicken embryo livers. The concentrations of PCDDs/Fs, PCBs and 15 PAHs in the samples were also determined. The polyaromatic fractions of the sediment samples were more potent as EROD-inducers than the diaromatic fractions. Only a small part of the EROD-induction caused by the polyaromatic fractions could be explained by the analysed PAHs in the samples, indicating presence of non-quantified polyaromatic EROD-inducing compounds in the samples. A greater pollution by EROD-inducing diaromatic and polyaromatic compounds on the east coast site than on the west coast site was seen. The filtration activities and faeces production of the mussels on the east coast experimental site increased the sedimentation of PCDDs/Fs, PCBs and PAHs. The described bioassay proved very useful in the assessment of dioxin-like compounds in both abiotic and biotic samples from the marine environment.     

Use of mode-converted waves in marine seismic data to investigate the lithology of the sub-bottom sediments in Isfjorden,Svalbard

The compression wavefield is efficiently converted to shear-wave energy at post-critical angles in areas of high impedance contrast at the sea floor. We have analysed mode-converted shear waves in a data set acquired with a hybrid marine/land geometry in Isfjorden, Svalbard. Through a kinematic 2D ray-tracing modellingV _p/V_s ratios for part of the uppermost 5km of the crust are obtained. Low values (V _p /V _s =1.65) are tentatively associated with the section of Devonian sandstones which appears to attain a minimum thickness of 1.5km below 3 km depth about 10km west of Kapp Thorden.     

Remarks on sequence stratigraphy and taphonomy of the Malvinokaffric shelly fauna during the KAČÁK Event in the Apucarana Sub-basin (Paraná Basin), Brazil

The Eifelian–Givetian (Middle Devonian) transition constituted an important paleoenvironmental event for the Malvinokaffric Realm in the Apucarana Sub-basin (Paraná Basin). This study highlights integration between taphonomy and sequence stratigraphy, and four depositional sequences are identified during the transition. In Sequence 1, the presence of a typical normal-sized Malvinokaffric fauna is recorded. In the transgressive systems tract (TST) of Sequence 2, no benthic fossils are present, and this is interpreted as a stratigraphic marker of an event of significant paleoenvironmental change (KA?ÁK Event). In Sequence 3, the TST has abundant bioclasts, which become rarer toward the top of the section, i.e., within the transgressive systems tract. The original habitat of this autochthonous to parautochthonous fauna was a low-energy environment between the fair weather wave base and the storm wave base of the Devonian epicontinental sea. In the highstand systems tract of this sequence, the presence of normal-sized Pennaia paulianna and lingulids demonstrates the return of more ambient conditions. Sequence 4 is of Carboniferous age. Its limit is a second-order sequence boundary recording a lowstand systems tract formed by a fluvial depositional system. The low diversity and the disappearance of taxa are not the result of a taphonomic bias, but reflect the post-KA?ÁK Event.