Search results for "carbon"
showing 10 items of 6057 documents
AGU Centennial Grand Challenge: Volcanoes and Deep Carbon Global CO 2 Emissions From Subaerial Volcanism—Recent Progress and Future Challenges
2020
Quantifying the global volcanic CO2 output from subaerial volcanism is key for a better understanding of rates and mechanisms of carbon cycling in and out of our planet and their consequences for the long-term evolution of Earth's climate over geological timescales. Although having been the focus of intense research since the early 1990s, and in spite of recent progress, the global volcanic CO2 output remains inaccurately known. Here we review past developments and recent progress and examine limits and caveats of our current understanding and challenges for future research. We show that CO2 flux measurements are today only available for ~100 volcanoes (cumulative measured flux, 44 Tg CO2/y…
Ecological assessment of developing carbon sequestration in Shenyang, China
2012
Carbon sequestration in urban ecosystems is becoming an international climate change initiative for sustainable development. Drawing upon field work undertaken in the author's native Shenyang, China, this research reports upon the natural process of carbon sequestration from the atmosphere into urban ecosystems. The risks associated within carbon sequestration in urban ecosystems are investigated and utilised the analysis of ecological carbon cycle status and integrated climate policy with reference to the sustainable development of urban planning. The primary method of this paper is the ecologically–based life assessment of urban ecosystems relevant to tackling barriers for developing carb…
Evaporite karst in Sicily
2007
Karst areas are distributed over most of Sicily. The most widespread karst rocks are carbonates, particularly limestones, but karst phenomena can also be seen in evaporites and particularly in salt mines. This report provides an overview of evaporite karst in Sicily, along with a “case history” that shows some of the evaporite karst risks to the environment. In the centre and south of Sicily, a thick sequence of Messinian evaporite rocks are subject to dissolution from meteoric and formation waters. In areas where potassium salts and rock salts are being mined, some geomorphologic changes result from the drilling of boreholes and the collapse of underground mines, thus lowering or collapsin…
Hydrogeochemistry and stable isotopes of thermal springs: earthquake-related chemical changes along Belice Fault (Western Sicily)
2001
Abstract Three geothermal systems, Montevago, Castellammare-Alcamo and Sciacca, are located along the main seismogenetic structures in Western Sicily. Concentrations of dissolved species including the gases CO 2 , N 2 , He and the results of stable isotope measurements δ 18 O, δ D and δ 13 C TDIC in water samples collected from six thermal springs and 28 cold discharges were used to characterise their feeder aquifers and to reveal the relationships between water chemistry and regional seismicity. The Sciacca thermal springs differ chemically and isotopically from those of Montevago and the Castellammare-Alcamo areas. The inferred deep end-members of the thermal waters of Montevago and Caste…
Potential and limits of combining studies of coarse- and fine-grained sediments for the coastal event history of a Caribbean carbonate environment
2013
The coastal deposits of Bonaire, Leeward Antilles, are among the most studied archives for extreme-wave events (EWEs) in the Caribbean. Here we present more than 400 electron spin resonance (ESR) and radiocarbon data on coarse-clast deposits from Bonaire’s eastern and western coasts. The chronological data are compared to the occurrence and age of fine-grained extremewave deposits detected in lagoons and floodplains. Both approaches are aimed at the identification of EWEs, the differentiation between extraordinary storms and tsunamis, improving reconstructions of the coastal evolution, and establishing a geochronological framework for the events. Although the combination of different method…
Geological Map of the Rocca Busambra-Corleone region (western Sicily, Italy): explanatory notes
2011
The geology of the Rocca Busambra-Corleone region, in centralwestern Sicily, is relevant to the understanding of the central sector of the Maghrebian-Sicilian fold-and-thrust belt. In the investigated area Mesozoic shallow- and deep-water carbo - nate deposits pertaining respectively to the Trapanese and the Sica - nian successions, and a thick Oligo-Miocene numidian flysch body, crop out. Minor outcrops of Cretaceous-Palaeogene Sicilide complex and syn-orogenic deposits of the Late Serravallian-Early Messinian Castellana Sicula and Terravecchia formations are also present. A structural analysis reveals complex tectonic relationships between the Trapanese carbonate platform tectonic unit (t…
Carboniferous and Cretaceous mafic–ultramafic massifs in Inner Mongolia (China): A SHRIMP zircon and geochemical study of the previously presumed int…
2012
Abstract We present SHRIMP zircon ages and whole-rock geochemical data to identify mafic–ultramafic massifs of early Carboniferous and early Cretaceous ages from northern Inner Mongolia, China. The early Carboniferous massifs (Chongenshan–Xiaobaliang–Wusnihei) comprise predominantly lherzolite and minor gabbroic rocks. Zircons from a microgabbro (e Nd (t) = 9.8) and a plagiogranite (e Nd (t) = 9) yielded weighted mean 206 Pb/ 238 U ages of 354 ± 7 Ma and 333 ± 4 Ma, that we interpret as reflecting the time of zircon (and magma) crystallization. A volcanic breccia resting unconformably on the ultramafic rocks (serpentinites) has an eruption age of 300 ± 2 Ma and provides a younger minimum …
Geochemistry and potential use of groundwater in the Rocca Busambra area (Sicily, Italy)
2008
In the Rocca Busambra area (mid-west Sicily, Italy), from November 1999 to July 2002, 23 water points including wells and springs were sampled and studied for their chemical and isotopic compositions. Two rain gauges were also installed at different altitudes, and rainwater was collected monthly to determine the isotopic composition. The obtained results revealed the Rocca Busambra carbonate complex as being the main recharge area on account of its high permeability value. From a chemical view point, two main groups of water can be distinguished: calcium–magnesium–bicarbonate-type and calcium–magnesium–chloride–sulphate-type waters. The first group reflects the dissolution of the carbonate …
Continuous monitoring of hydrogen and carbon dioxide at Mt Etna
2013
article i nfo This study assessed the use of an H2 fuel cell as an H2-selective sensor for volcano monitoring. The resolution, repeatability, and cross-sensitivity of the sensor were investigated and evaluated under known laboratory conditions. A tailor-made device was developed and used for continuously monitoring H2 and CO2 at Mt Etna throughout 2009 and 2010. The temporal variations of both parameters were strongly correlated with the evolution of the volcanic activity during the monitoring period. In particular, the CO2 flux exhibited long-term variations, while H2 exhibited pulses immediately before the explosive activity that occurred at Mt Etna during 2010.
Deglaciation history of Latvia
2004
This chapter discusses the deglaciation history of Latvia. The earliest deglaciation schemes of Latvia were based entirely on morphological features. The spatial distribution of glacial landforms, with crests transverse to glacier movement combined with radiocarbon dates and biostratigraphical evidence, have provided the principal data for the reconstruction of the deglaciation process from the mid-1960s until the present. A deglaciation history should be based on multiple criteria. Attention should be paid to the identification of ice-marginal formations, and complex studies are also needed, including the investigation of the spatial distribution and internal composition of subglacial land…