Search results for " Lake"

Short-period volcanic gas precursors to phreatic eruptions: Insights from Poás Volcano, Costa Rica

2016

Texto completo del documento Volcanic eruptions involving interaction with water are amongst the most violent and unpredictable geologic phenomena on Earth. Phreatic eruptions are exceptionally difficult to forecast by traditional geophysical techniques. Here we report on short-term precursory variations in gas emissions related to phreatic blasts at Poás volcano, Costa Rica, as measured with an in situ multiple gas analyzer that was deployed at the edge of the erupting lake. Gas emitted from this hyper-acid crater lake approaches magmatic values of SO2/CO21–6 days prior to eruption. The SO2flux derived from magmatic degassing through the lake is measureable by differential optical absorpti…

Invasive vascular plant species of oxbow lakes in south-western Poland

2015

Abstract Natural water reservoirs are very valuable floristic sites in south-western Poland. Among them, the most important for the preservation of biodiversity of flora are oxbow lakes. The long-term process of human pressure on habitats of this type caused disturbances of their biological balance. Changes in the water regime, industrial development and chemisation of agriculture, especially in the period of the last two hundred years, led to systematic disappearances of localities of many plant species connected with rare habitats and also to the appearance of numerous invasive plant species. They are: Azolla filiculoides, Echinocystis lobata, Erechtites hieraciifolia, Impatiens glandulif…

Gas in volcanic lakes: from dissolved gases to lake gas plumes

Monticchio Lakes

2020

The crater lakes are a natural hazard for the population living near them because they can generate liminic explosions, like as the disaster of Nyos lake (Cameroon 1986), in which 1476 people and thousands of animals died. Crater lakes are able to store magmatic and hydrothermal gases and solubilising them into the water. An overpressure of the dissolved gases can generate a limnic eruption. Italy is characterised by an intense volcanic and seismic activity. Evidences of this past volcanism are the numerous crater lakes in Lazio and Campania. The most famous are Bolsena lakes, Vico, Bracciano, Monticchio lakes, Mezzano, Martignano, Albano, Nemi, Averno. The Monticchio lakes (Piccolo Lake (L…

Impacts sur le climat régional induits par l'immersion d'une zone aride : cas de Chott Jérid (sud de la Tunisie).

2017

This work aims to show the possible impacts on the regional climate that could be caused by the partial immersion ofChott Jérid located in the south of Tunisia. Climate simulations have been carried out using the Weather Research andForecasting (WRF) model to compare the present climate of the Chott area simulated over the period 1991-2011 under realconditions of land use to the climate simulated in the fictional presence of a vast artificial waterbody (or lake). Comparisonsshowed that the lake would have a particularly moderating effect on average air temperatures. The sensible heat flux wouldincrease substantially during the winter and decrease during the summer, while latent heat and moi…

Variation in zooplankton diets in contrasting small lakes, inferred from stable isotope analyses

2007

Food web structure of an Arctic lake (Pulmankijärvi, northern Finland) studied by stable isotope analyses

2007

Ilmasto ja sen määräämät luonnonolot Suomen asutuksen ja maatalouden historiassa

2012

Planktivorous vendace (Coregonus albula) utilise algae-derived fatty acids for biomass increase and lipid deposition

2018

Spatial and seasonal variation in the abundance and composition of phytoplankton and other basal resources (bacteria, terrestrial detritus) influence the availability of essen-tial polyunsaturated fatty acids (PUFA) for upper trophic levels in lake food webs. We studied accumulation, composition and content of fatty acids in planktivorous ven-dace (Coregonus albula) muscle tissue during the summer feeding period (May to late September) in six boreal lakes. Vendace muscle fatty acid content increased from ~17.7 mg/g DW to ~28.1 mg/g DW from spring to summer, corresponding to a ~59% increase in total fatty acids. PUFA accounted for 45%–65% of all fatty acids, and the most abundant fatty acid …

Dikerogammarus villosus (Sowinsky, 1894) (Crustacea, Amphipoda) colonizes next alpine lake – Lac du Bourget, France.

2007

4 pages; Dikerogammarus villosus has been recorded for the first time in the alpine lake – Lac du Bourget, French Alps. Low abundance of the alien species in gathered samples suggests that the colonization is just in its initial stage. Two native gammarid species: Gammarus fossarum (Koch, 1835) and G. pulex (Linnaeus, 1758) are still present in the lake. The invader has most probably reached the lake through the Canal de Savières joining the lake to the Rhone River in which it has been already present since late 1990s.