Search results for " Plum"
showing 10 items of 111 documents
Winter male plumage coloration correlates with breeding status in a cooperative breeding species
2007
The function of colored ornaments is usually related to the signaling of individual quality in intra- and intersexual interactions. In cooperative breeding species, where only a fraction of the male population access the breeding status and the other fraction has the option to help breeding pairs, colored traits might provide the females with a reliable information on the quality of potential mate. Males of the cooperative breeding azure-winged magpies (Cyanopica cyanus) display conspicuous blue plumage coloration. Here we explored the role played by structural blue coloration of males and the probability of becoming a breeder or a helper. Birds were trapped during 4 consecutive years, and …
Percorsi ascensionali e viaggi fra i luoghi della ‘memoria’. Una lettura di "Guida per salire al monte" di Lucio Piccolo.
2019
L’articolo è incentrato sul valore che il tema del viaggio riveste nella poesia di Lucio Piccolo e sulla specifica declinazione che, in riferimento alla relazione con il paesaggio e alla percezione della natura, animale e vegetale, esso assume nell’opera dell’autore. L’indagine prende le mosse dalla lettura di "Guida per salire al monte", componimento d’apertura di "Plumelia", la terza raccolta piccoliana pubblicata nel 1967 (L. Piccolo, "Plumelia", All’insegna del Pesce d’Oro, Milano 1967). La poesia, attraverso il ritmo narrativo largo del poema in versi liberi e le dettagliate descrizioni del paesaggio, ricompone i piani sfaccettati di una geografia memoriale e illustra, secondo le modal…
BVLOS UAS Operations in Highly-Turbulent Volcanic Plumes.
2020
Long-range, high-altitude Unoccupied Aerial System (UAS) operations now enable in-situ measurements of volcanic gas chemistry at globally-significant active volcanoes. However, the extreme environments encountered within volcanic plumes present significant challenges for both air frame development and in-flight control. As part of a multi-disciplinary field deployment in May 2019, we flew fixed wing UAS Beyond Visual Line of Sight (BVLOS) over Manam volcano, Papua New Guinea, to measure real-time gas concentrations within the volcanic plume. By integrating aerial gas measurements with ground- and satellite-based sensors, our aim was to collect data that would constrain the emission rate of …
Mercury gas emissions from La Soufrière Volcano, Guadeloupe Island (Lesser Antilles)
2009
Abstract Quantifying mercury (Hg) emissions from active volcanoes is of particular interest for better constraining the global cycle and environmental impact of this highly toxic element. Here we report on the abundance of total gaseous (TGM = Hg 0 (g) + Hg II (g) ) and particulate (Hg (p) ) mercury in the summit gas emissions of La Soufriere andesitic volcano (Guadeloupe island, Lesser Antilles), where enhanced degassing of mixed hydrothermal-magmatic volatiles has been occurring since 1992 from the Southern summit crater. We demonstrate that Hg in volcanic plume occurs predominantly as gaseous mercury, with a mean TGM/Hg (p) mass ratio of ~ 63. Combining the mean TGM/H 2 S mass ratio of …
Plume composition and volatile flux of Nyamulagira volcano, Democratic Republic of Congo, during birth and evolution of the lava lake, 2014-2015
2017
Very little is known about the volatile element makeup of the gaseous emissions of Nyamulagira volcano. This paper tries to fill this gap by reporting the first gas composition measurements of Nyamulagira’s volcanic plume since the onset of its lava lake activity at the end of 2014. Two field surveys were carried out on 1 November 2014, and 13–15 October 2015. We applied a broad toolbox of volcanic gas composition measurement techniques in order to geochemically characterize Nyamulagira’s plume. Nyamulagira is a significant emitter of SO2, and our measurements confirm this, as we recorded SO2 emissions of up to ~ 14 kt/d during the studied period. In contrast to neighbouring Nyiragongo volc…
Measurements of volcanic SO2 and CO2 fluxes by combined DOAS, Multi-GAS and FTIR observations: a case study from Turrialba and Telica volcanoes
2014
Over the past few decades, substantial progress has been made to overcome the technical difficulties of continuously measuring volcanic SO2 emissions. However, measurements of CO2 emissions still present many difficulties, partly due to the lack of instruments that can directly measure CO2 emissions and partly due to its strong atmospheric background. In order to overcome these difficulties, a commonly taken approach is to combine differential optical absorption spectroscopy (DOAS) by using NOVAC scan-DOAS instruments for continuous measurements of crateric SO2 emissions, and electrochemical/NDIR multi-component gas analyser system (multi-GAS) instruments for measuring CO2/SO2 ratios of exc…
Application and evaluation of biomagnetic and biochemical monitoring of the dispersion and deposition of volcanically-derived particles at Mt. Etna, …
2010
article i nfo Article history: Received 6 August 2009 Accepted 4 January 2010 Available online xxxx Biomagnetic monitoring, using tree leaves as passive surfaces for particle collection, has been shown to be a promising technique for assessing the dispersion and deposition of particles in the context of anthropogenic pollution. By comparing leaves' magnetic properties with trace metal levels measured in the leaves, we here assess the utility of the biomagnetic technique as a sensitive, fast and inexpensive method for assessment of volcanic plume deposition. Samples of sweet chestnut leaves (Castanea sativa) were collected from the area surrounding Mt. Etna volcano in Sicily during the 2008 …
First 13C/12C isotopic characterisation of volcanic plume CO2
2010
We describe analytical details and uncertainty evaluation of a simple technique for the measurement of the carbon isotopic composition of CO2 in volcanic plumes. Data collected at Solfatara and Vulcano, where plumes are fed by fumaroles which are accessible for direct sampling, were first used to validate the technique. For both volcanoes, the plume-derived carbon isotopic compositions are in good agreement with the fumarolic compositions, thus providing confidence on the method, and allowing its application at volcanoes where the volcanic component is inaccessible to direct sampling. As a notable example, we applied the same method to Mount Etna where we derived a δ13C of volcanic CO2 betw…
Do Volcanic Eruptions Solve Global Atmospheric Mercury Pollution?
2011
Besides human activities, volcanoes also introduce significant quantities of potentially harmful chemical compounds into the environment, mainly in the forms of gases and particles. High-temperature emissions from persistently degassing volcanoes are a known source of trace metal emissions to the atmosphere which may have important environmental consequences. Among these metals, mercury (Hg) is of particular interest since it is a toxic volatile metal found at elevated concentrations in remote regions of the world. Many natural Hg pathways include a recycled component of anthropogenic material. The anthropogenic contribution to the global atmospheric Hg budget is now well constrained, with …
Plume chemistry and potential impacts of the plume from the recent activity at Halema’uma’u, Kilauea, USA.
2009
Since the 19 March 2008 explosion within Halema‘uma‘u that formed the new vent at Kilauea’s summit, degassing rates have been greatly elevated above the levels typical of previous years. The location and subsequent dispersion of this new degassing presents its own specific problems compared to that in the east rift zone. For example, throughout 2008 the Halema’uma’u plume was generally blown through the Kau desert, directly affecting downwind communities. In this study we present measurements made in July and halogens (HF, HCl, HBr and HI) in the new 2008. We characterize the gas chemistry in terms of SO 2 plume from Halema’uma’u in order to compare them with other plumes worldwide, includi…