Investigating Volcanic Plumes from Mt. Etna Eruptions of December 2015 by Means of AVHRR and SEVIRI Data

In early December 2015, a rapid sequence of strong paroxysmal events took place at the Mt. Etna crater area (Sicily, Italy). Intense paroxysms from the Voragine crater (VOR) generated an eruptive column extending up to an altitude of about 15 km above sea level. In the following days, other minor ash emissions occurred from summit craters. In this study, we present results achieved by monitoring Mt. Etna plumes by means of RSTASH (Robust Satellite Techniques-Ash) algorithm, running operationally at the Institute of Methodologies for Environmental Analysis (IMAA) on Advanced Very High Resolution Radiometer (AVHRR) data. Results showed that RSTASH detected an ash plume dispersing from Mt. Etna towards Ionian Sea starting from 3 December at 08:40 UTC, whereas it did not identify ash pixels on satellite data of same day at 04:20 UTC and 04:40 UTC (acquired soon after the end of first paroxysm from VOR), due to a mixed cloud containing SO2 and ice. During 8–10 December, the continuity of RSTASH detections allowed us to estimate the mass eruption rate (an average value of about 1.5 × 103 kg/s was retrieved here), quantitatively characterizing the eruptive activity from North East Crater (NEC). The work, exploiting information provided also by Spinning Enhanced Visible and Infrared Imager (SEVIRI) data, confirms the important contribution offered by RSTASH in identifying and tracking ash plumes emitted from Mt. Etna, despite some operational limitations (e.g., cloud coverage). Moreover, it shows that an experimental RST product, tailored to SEVIRI data, for the first time used and preliminarily assessed here, may complement RSTASH detections providing information about areas mostly affected by volcanic SO2.

Download Full-text

Diversity of the Cyanoprokaryota in polar deserts of Innvika cove North-East Land (Nordaustlandet) Island, Spitsbergen

Czech Polar Reports ◽

10.5817/cpr2016-1-7 ◽

2016 ◽

Vol 6 (1) ◽

pp. 66-79 ◽

Cited By ~ 1

Author(s):

Denis Davydov

Keyword(s):

Common Species ◽

Southern Coast ◽

Nostoc Commune ◽

The West ◽

North East ◽

West Part ◽

Wet Rocks ◽

First Time ◽

Very High ◽

Sørensen Index

The study of polar deserts cyanoprokaryotes up to now is few. Foremost this is connected with difficulty visiting of the area. The paper presents the results of a study of сyanoprokaryota on the southern coast of Innvika cove (Fotherbyfjorden bay, North-East Land Island, Spitsbergen archipelago). A total of 74 taxa were observed in various habitats of investigated area. Nine species are reported for the first time for Spitsbergen flora. Gloeocapsopsis magma (20 observations), Nostoc commune (19), Microcoleus autumnalis (17) were the most common species in the investigated samples. The most number of species (42) was found on wet rocks. The similarity Sorensen index between wet rock species, seepage species and pools species is very high. It can mean that for many species the only necessary preference in habitat is a rock substrate and wetting. Most similar are the flora of the Innvika area and flora of the west part of Oscar II Land (61%).

Download Full-text

The Contribution of Multi-Sensor Infrared Satellite Observations to Monitor Mt. Etna (Italy) Activity during May to August 2016

Remote Sensing ◽

10.3390/rs10121948 ◽

2018 ◽

Vol 10 (12) ◽

pp. 1948 ◽

Cited By ~ 16

Author(s):

Francesco Marchese ◽

Marco Neri ◽

Alfredo Falconieri ◽

Teodosio Lacava ◽

Giuseppe Mazzeo ◽

...

Keyword(s):

Summit Crater ◽

Satellite Observations ◽

Fumarolic Activity ◽

Landsat 8 ◽

Surveillance Systems ◽

Average Value ◽

North East ◽

The North ◽

Strombolian Eruption ◽

Mt Etna

In May 2016, three powerful paroxysmal events, mild Strombolian activity, and lava emissions took place at the summit crater area of Mt. Etna (Sicily, Italy). During, and immediately after the eruption, part of the North-East crater (NEC) collapsed, while extensive subsidence affected the Voragine crater (VOR). Since the end of the May eruptions, a diffuse fumarolic activity occurred from a fracture system that cuts the entire summit area. Starting from 7 August, a small vent (of ~20–30 m in diameter) opened up within the VOR crater, emitting high-temperature gases and producing volcanic glow which was visible at night. We investigated those volcanic phenomena from space, exploiting the information provided by the satellite-based system developed at the Institute of Methodologies for Environmental Analysis (IMAA), which monitors Italian volcanoes in near-real time by means of the RSTVOLC (Robust Satellite Techniques–volcanoes) algorithm. Results, achieved integrating Advanced Very High Resolution Radiometer (AVHRR) and Moderate Resolution Imaging Spectroradiometer (MODIS) observations, showed that, despite some issues (e.g., in some cases, clouds masking the underlying hot surfaces), RSTVOLC provided additional information regarding Mt. Etna activity. In particular, results indicated that the Strombolian eruption of 21 May lasted longer than reported by field observations or that a short-lived event occurred in the late afternoon of the same day. Moreover, the outcomes of this study showed that the intensity of fumarolic emissions changed before 7 August, as a possible preparatory phase of the hot degassing activity occurring at VOR. In particular, the radiant flux retrieved from MODIS data decreased from 30 MW on 4 July to an average value of about 7.5 MW in the following weeks, increasing up to 18 MW a few days before the opening of a new degassing vent. These outcomes, in accordance with information provided by Sentinel-2 MSI (Multispectral Instrument) and Landsat 8-OLI (Operational Land Imager) data, confirm that satellite observations may also contribute greatly to the monitoring of active volcanoes in areas where efficient traditional surveillance systems exist.

Download Full-text

YUKAGIR GEOGRAPHICAL TERMS IN TOPONYMY OF THE KOLYMA RIVER BASIN

EurasianUnionScientists ◽

10.31618/esu.2413-9335.2020.9.73.717 ◽

2020 ◽

Vol 9 (4(73)) ◽

pp. 29-33

Author(s):

N.S. Bagdaryyn

Keyword(s):

River Basin ◽

Semantic Analysis ◽

Comparative Method ◽

Linguistic Analysis ◽

Word Formation ◽

Morphological Features ◽

North East ◽

The North ◽

First Time ◽

Kolyma River

The article continues the author's research on the toponymy of the North-East of the Sakha Republic, in particular the Kolyma river basin, in the aspect of the interaction of related and unrelated languages. The relevance of this work is defined in the description of local geographical terminology of Yukagir origin, as a valuable and important material in the further study of toponymy of the region. For the first time, the toponymy of the Kolyma river basin becomes the object of sampling and linguistic analysis of toponyms with local geographical terms of Yukagir origin in order to identify and analyze them linguistically. The research was carried out by comparative method, word formation, structural, lexical and semantic analysis. As a result of the research, phonetic and morphological features are revealed, the formation of local geographical terms and geographical names of Yukagir origin is outlined, and previously unrecorded semantic shifts and dialectisms are revealed. The most active in the formation of terms and toponyms is the geographical term iилil / eҕal 'coast‘, which is justified by the representation of the Yukagirs’ coast' home, housing

Download Full-text

Shell-crossing in a ΛCDM Universe

Monthly Notices of the Royal Astronomical Society Letters ◽

10.1093/mnrasl/slaa198 ◽

2020 ◽

Vol 501 (1) ◽

pp. L71-L75

Author(s):

Cornelius Rampf ◽

Oliver Hahn

Keyword(s):

Dark Matter ◽

Perturbation Theory ◽

Large Scale ◽

Cold Dark Matter ◽

Three Dimensional ◽

Random Initial Data ◽

Recursion Relations ◽

Indispensable Tool ◽

First Time ◽

Very High

ABSTRACT Perturbation theory is an indispensable tool for studying the cosmic large-scale structure, and establishing its limits is therefore of utmost importance. One crucial limitation of perturbation theory is shell-crossing, which is the instance when cold-dark-matter trajectories intersect for the first time. We investigate Lagrangian perturbation theory (LPT) at very high orders in the vicinity of the first shell-crossing for random initial data in a realistic three-dimensional Universe. For this, we have numerically implemented the all-order recursion relations for the matter trajectories, from which the convergence of the LPT series at shell-crossing is established. Convergence studies performed at large orders reveal the nature of the convergence-limiting singularities. These singularities are not the well-known density singularities at shell-crossing but occur at later times when LPT already ceased to provide physically meaningful results.

Download Full-text

The Research on Computation of Researchers Certainty Factor of Bridge's Durability Evaluation Based on the Indeterminate AHP

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.578-579.1469 ◽

2014 ◽

Vol 578-579 ◽

pp. 1469-1472

Author(s):

Xiao Zhen Chen ◽

Xue Jun Zhang

Keyword(s):

Lower Bound ◽

Similarity Theory ◽

Research Result ◽

Weight Coefficient ◽

Practical Experience ◽

Relative Importance ◽

Certainty Factor ◽

Average Value ◽

Judgment Matrix ◽

Very High

Because of fuzziness, uncertainty of structure and researchers practical experience, it is more practical to express the relative importance of indexes with interval number. Firstly, according to researchers indeterminate judgment matrix, the upper and lower bound matrixes are formed; secondly, the similarity and the differences of the upper and lower bound matrixes of the relative importance matrix from different experts is studied by using the similarity theory of vector; lastly, certainty factor of researchers according to the upper and lower bound matrixes can be calculated, and the average value is regarded as the researchers certainty factor. The certainty factors of researchers upper and lower bound matrixes are consider together, the researchers experience is fully considered and the error from indeterminate judgment matrix to indeterminate judgment matrix is avoided. The result affords basis to calculate the weight coefficient, the research result comparing with the other method showed that the computation accuracy in this paper was very high.

Download Full-text

Mercury concentrations in thermal waters of the Bolshoi Semyachik hydrothermal system, Russia, Kamchatka.

10.5194/egusphere-egu21-15094 ◽

2021 ◽

Author(s):

Anton Nuzhdaev

Keyword(s):

Hydrothermal System ◽

Kamchatka Peninsula ◽

Hydrothermal Systems ◽

Thermal Waters ◽

Hydrothermal Solutions ◽

Average Value ◽

Thermal Fields ◽

Gas Jets ◽

First Time ◽

Hydrothermal Fields

The study of mercury receipt within volcanic activity zones and large hydrothermal systems recently causes the big interest connected with attempts of an estimation of volumes of natural mercury receipt on a daily surface.The hydrothermal system connected with volcanic massif Big Semyachik is one of the largest on the territory of Kamchatka peninsula. On the surface, the hydrothermal system is manifested by three large hydrothermal fields - the Verhnee Field, the parychay Dolina, and the Northern Crater of the Central Semyachik, the heat export from which is estimated at 300 MW (Vakin, 1976). On the surface of the thermal fields hot thermal waters and powerful steam-gas jets are unloaded.&#160; At the same time, due to the inaccessibility of thermal fields remain poorly studied, and in particular, there is no information on the concentrations of mercury in hydrothermal solutions.During fieldwork in 2020 all types of thermal waters were sampled, chemical types of waters were established, concentrations of mercury in hydrothermal solutions: for hot thermal waters the average value of mercury was - 0.44 mcg / L, and in steam-gas jets - the average value of mercury was - 4.60 mcg / L.Thus, in the course of the work the data on concentrations of mercury in hydrothermal solutions of one of the largest hydrothermal systems of Kamchatka were received for the first time.&#160;

Download Full-text

Chemical-physical constraints of the 2015 eruptive activity of Mt. Etna: new insights from thermo-barometry and geochemistry of olivine-hosted melt inclusions

10.5194/egusphere-egu21-15199 ◽

2021 ◽

Author(s):

Pier Paolo Giacomoni ◽

Federico Casetta ◽

Virginia Valenti ◽

Carmelo Ferlito ◽

Gabriele Lanzafame ◽

...

Keyword(s):

Melt Inclusions ◽

New South ◽

Basalt Magma ◽

Feeding System ◽

Physical Constraints ◽

Eruptive Event ◽

North East ◽

Central Crater ◽

Mt Etna ◽

Crystallization Conditions

The concomitant activation off all four summit craters of Mt. Etna during the December 2015 eruptive event allow us to investigate the chemical-physical crystallization conditions and magma dynamics in the shallower portion of the open-conduit feeding system. In this study, we discuss new petrological, geochemical and thermo-barometric data as well as the composition of major element and volatile content (H2O, CO2, F, Cl and S) of olivine-hosted melt inclusions from the explosive and effusive products emitted during the December 2015 eruptive event.Results and rhyolite-MELTS thermodynamic modelling of mineral phase stability highlight the relatively shallow crystal equilibrium depth prior to the eruption ranging from 400-500 MPa for Central Crater and North East Crater, up to 200 MPa below the New South East Crater. The study of high-pressure and high-temperature homogenized olivine-hosted melt inclusions allowed us to identify the composition of the almost primary alkali-basalt magma (11.8 wt% MgO) containing up to 4.9 wt% and 8151 ppm of H2O and CO2 respectively. The results, together with those already reported for the previous paroxystic events of the 2011-2012 (Giacomoni et al., 2018), reinforce the model of a vertically extended feeding system and highlight that the activity at the New South East Crater was fed by a magma residing at significant shallower depth with respect to Central Craters and North East Crater, although all conduits are fed by a common deep (P = 530-440 MPa) basic magmatic refilling. Plagioclase stability model and dissolution and resorption textures confirm its dependence on H2O content, thus suggesting that further studies on the effect that flushing from fluids with different H2O/CO2 ratio are needed in order to understand the eruption triggering mechanisms of paroxystic fountaining.&#160;ReferencesGiacomoni P., Coltorti M., Mollo S., Ferlito C., Braiato M., Scarlato P. 2018. The 2011-2012 paroxysmal eruptions at Mt. Etna volcano: Insights on the vertically zoned plumbing system. JVGR 349, 370-391.

Download Full-text

General method for cloning Neurospora crassa nuclear genes by complementation of mutants

Molecular and Cellular Biology ◽

10.1128/mcb.5.9.2272-2278.1985 ◽

1985 ◽

Vol 5 (9) ◽

pp. 2272-2278

Author(s):

R A Akins ◽

A M Lambowitz

Keyword(s):

Neurospora Crassa ◽

Genomic Library ◽

Selection Procedure ◽

Nuclear Genes ◽

Shuttle Vectors ◽

Sib Selection ◽

First Time ◽

Very High ◽

Restriction Site Polymorphisms ◽

General Method

We have developed a sib selection procedure for cloning Neurospora crassa nuclear genes by complementation of mutants. This procedure takes advantage of a modified N. crassa transformation procedure that gives as many as 10,000 to 50,000 stable transformants per microgram of DNA with recombinant plasmids containing the N. crassa qa-2+ gene. Here, we describe the use of the sib selection procedure to clone genes corresponding to auxotrophic mutants, nic-1 and inl. The identities of the putative clones were confirmed by mapping their chromosomal locations in standard genetic crosses and using restriction site polymorphisms as genetic markers. Because we can obtain very high N. crassa transformation frequencies, cloning can be accomplished with as few as five subdivisions of an N. crassa genomic library. The sib selection procedure should, for the first time, permit the cloning of any gene corresponding to an N. crassa mutant for which an appropriate selection can be devised. Analogous procedures may be applicable to other filamentous fungi before the development of operational shuttle vectors.

Download Full-text

The effect of seed rate and nitrogen fertilizer on the yield and nutritive value of oat-vetch mixtures

The Journal of Agricultural Science ◽

10.1017/s0021859600084100 ◽

1989 ◽

Vol 112 (1) ◽

pp. 57-66 ◽

Cited By ~ 13

Author(s):

N. Moreira

Keyword(s):

Nitrogen Fertilizer ◽

Crude Protein ◽

Nutritive Value ◽

High Yield ◽

Mineral Nutrient ◽

Yield Response ◽

N Nutrition ◽

North East ◽

Positive Effect ◽

Very High

SummaryExperiments were conducted on the seed rates of the components of oat-vetch mixtures combined with varying rates of nitrogen fertilizer in a rainfed area of north-east Portugal in 1982–3 and 1984–5.Forage oats grown alone showed a very high yield response to N and rainfall ranging from 30 to 18·2 t D.M./ha, but had a very low crude protein concentration (37–54 g/kg D.M.) and a poor mineral nutrient composition.The increased use of vetch in the seed mixture had a buffering effect on dry-matter (D.M.) yield but this depended very much on crop N nutrition. For N-deficient conditions vetch inclusion increased the D.M. yield and had a strong positive effect on total forage crude protein (CP) and mineral composition. When crop N nutrition was good, very high D.M. yields (> 12 t D.M./ha) were possible using a high proportion of oats, with vetch making a reduced contribution to the yield and nutritive value of total forage.Seed rates suggested in the literature for Mediterranean conditions are adequate for low N inputs and low available soil N, but not for high D.M. yields which can only be obtained by using a higher proportion of oats and adequate N fertilizer.

Download Full-text

Visible AO Observations at Halpha for Accreting Young Planets

Proceedings of the International Astronomical Union ◽

10.1017/s1743921313007734 ◽

2013 ◽

Vol 8 (S299) ◽

pp. 32-33

Author(s):

L.M. Close ◽

K. Follette ◽

J.R. Males ◽

K. Morzinski ◽

T.J. Rodigas ◽

...

Keyword(s):

Adaptive Optics ◽

Binary Stars ◽

Optical Resolution ◽

Ccd Camera ◽

Short Exposure ◽

Low Mass ◽

Orion Trapezium ◽

First Time ◽

Adaptive Optics System ◽

Very High

AbstractWe utilized the new high-order (250-378 mode) Magellan Adaptive Optics system (MagAO) to obtain very high-resolution science in the visible with MagAO's VisAO CCD camera. In the good-median seeing conditions of Magellan (0.5–0.7″) we find MagAO delivers individual short exposure images as good as 19 mas optical resolution. Due to telescope vibrations, long exposure (60s) r' (0.63μm) images are slightly coarser at FWHM = 23-29 mas (Strehl ~ 28%) with bright (R < 9 mag) guide stars. These are the highest resolution filled-aperture images published to date. Images of the young (~ 1 Myr) Orion Trapezium θ1 Ori A, B, and C cluster members were obtained with VisAO. In particular, the 32 mas binary θ1 Ori C1C2 was easily resolved in non-interferometric images for the first time. Relative positions of the bright trapezium binary stars were measured with ~ 0.6–5 mas accuracy. In the second commissioning run we were able to correct 378 modes and achieved good contrasts (Strehl>20% on young transition disks at Hα). We discuss the contrasts achieved at Hα and the possibility of detecting low mass (~ 1–5 Mjup) planets (past 5AU) with our new SAPPHIRES survey with MagAO at Hα.

Download Full-text