Experimental strategies for the investigation of low temperature properties in granitic and pegmatitic melts

The physical behavior of silicate melts during the final stages of intrusion in the earth's crust are poorly understood. In particular, the low temperature limit of igneous petrogenesis is poorly constrained. The extreme differentiates of granitic magmatism that lead to pegmatite genesis span a very large range of composition not normally considered to be within the domain of igneous melt compositions. This combination of very low petrogenetic temperatures and extreme chemistries requires a concentrated effort for the determination of melt properties under conditions of pressure, temperature and composition appropriate to these systems. An experimental strategy for the determination of melt properties under appropriate conditions is presented. The determination of individual melt properties at very low temperatures is described with the aid of three examples, heat capacity, volume and viscosity. In this way the physical behavior of an important component of the earth's crust will become accessible

Long-term monitoring of SO2 quiescent degassing from Nyiragongo’s lava lake

The activity of open-vent volcanoes with an active lava-lake, such as Nyiragongo, is characterized by persistent degassing, thus continuous monitoring of the rate, volume and fate of their gas emissions is of great importance to understand their geophysical state and their potential impact. We report results of SO2 emission measurements from Nyiragongo conducted between 2004 and 2012 with a network of ground-based scanning-DOAS (Differential Optical Absorption Spectroscopy) remote sensors. The mean SO2 emission rate is found to be 13 ± 9 kg s−1, similar to that observed in 1959. Daily emission rate has a distribution close to log-normal and presents large inter-day variability, reflecting the dynamics of percolation of magma batches of heterogeneous size distribution and changes in the effective permeability of the lava lake. The degassed S content is found to be between 1000 and 2000 ppm from these measurements and the reported magma flow rates sustaining the lava lake. The inter-annual trend and plume height statistics indicate stability of a quiescently degassing lava lake during the period of study

Longer-term efficiency and safety of increasing the frequency of whole blood donation (INTERVAL): extension study of a randomised trial of 20 757 blood donors

Background: The INTERVAL trial showed that, over a 2-year period, inter-donation intervals for whole blood donation can be safely reduced to meet blood shortages. We extended the INTERVAL trial for a further 2 years to evaluate the longer-term risks and benefits of varying inter-donation intervals, and to compare routine versus more intensive reminders to help donors keep appointments. Methods: The INTERVAL trial was a parallel group, pragmatic, randomised trial that recruited blood donors aged 18 years or older from 25 static donor centres of NHS Blood and Transplant across England, UK. Here we report on the prespecified analyses after 4 years of follow-up. Participants were whole blood donors who agreed to continue trial participation on their originally allocated inter-donation intervals (men: 12, 10, and 8 weeks; women: 16, 14, and 12 weeks). They were further block-randomised (1:1) to routine versus more intensive reminders using computer-generated random sequences. The prespecified primary outcome was units of blood collected per year analysed in the intention-to-treat population. Secondary outcomes related to safety were quality of life, self-reported symptoms potentially related to donation, haemoglobin and ferritin concentrations, and deferrals because of low haemoglobin and other factors. This trial is registered with ISRCTN, number ISRCTN24760606, and has completed. Findings: Between Oct 19, 2014, and May 3, 2016, 20 757 of the 38 035 invited blood donors (10 843 [58%] men, 9914 [51%] women) participated in the extension study. 10 378 (50%) were randomly assigned to routine reminders and 10 379 (50%) were randomly assigned to more intensive reminders. Median follow-up was 1·1 years (IQR 0·7–1·3). Compared with routine reminders, more intensive reminders increased blood collection by a mean of 0·11 units per year (95% CI 0·04–0·17; p=0·0003) in men and 0·06 units per year (0·01–0·11; p=0·0094) in women. During the extension study, each week shorter inter-donation interval increased blood collection by a mean of 0·23 units per year (0·21–0·25) in men and 0·14 units per year (0·12–0·15) in women (both p<0·0001). More frequent donation resulted in more deferrals for low haemoglobin (odds ratio per week shorter inter-donation interval 1·19 [95% CI 1·15–1·22] in men and 1·10 [1·06–1·14] in women), and lower mean haemoglobin (difference per week shorter inter-donation interval −0·84 g/L [95% CI −0·99 to −0·70] in men and −0·45 g/L [–0·59 to −0·31] in women) and ferritin concentrations (percentage difference per week shorter inter-donation interval −6·5% [95% CI −7·6 to −5·5] in men and −5·3% [–6·5 to −4·2] in women; all p<0·0001). No differences were observed in quality of life, serious adverse events, or self-reported symptoms (p>0.0001 for tests of linear trend by inter-donation intervals) other than a higher reported frequency of doctor-diagnosed low iron concentrations and prescription of iron supplements in men (p<0·0001). Interpretation: During a period of up to 4 years, shorter inter-donation intervals and more intensive reminders resulted in more blood being collected without a detectable effect on donors' mental and physical wellbeing. However, donors had decreased haemoglobin concentrations and more self-reported symptoms compared with the initial 2 years of the trial. Our findings suggest that blood collection services could safely use shorter donation intervals and more intensive reminders to meet shortages, for donors who maintain adequate haemoglobin concentrations and iron stores. Funding: NHS Blood and Transplant, UK National Institute for Health Research, UK Medical Research Council, and British Heart Foundation

MPI-Ding reference glasses for in situ microanalysis: New reference values for element concentrations and isotope ratios

We present new analytical data of major and trace elements for the geological MPI-DING glasses KL2-G, ML3B-G, StHs6/80-G, GOR128-G, GOR132-G, BM90/21-G, T1-G, and ATHO-G. Different analytical methods were used to obtain a large spectrum of major and trace element data, in particular, EPMA, SIMS, LA-ICPMS, and isotope dilution by TIMS and ICPMS. Altogether, more than 60 qualified geochemical laboratories worldwide contributed to the analyses, allowing us to present new reference and information values and their uncertainties (at 95% confidence level) for up to 74 elements. We complied with the recommendations for the certification of geological reference materials by the International Association of Geoanalysts (IAG). The reference values were derived from the results of 16 independent techniques, including definitive (isotope dilution) and comparative bulk (e.g., INAA, ICPMS, SSMS) and microanalytical (e.g., LA-ICPMS, SIMS, EPMA) methods. Agreement between two or more independent methods and the use of definitive methods provided traceability to the fullest extent possible. We also present new and recently published data for the isotopic compositions of H, B, Li, O, Ca, Sr, Nd, Hf, and Pb. The results were mainly obtained by high-precision bulk techniques, such as TIMS and MC-ICPMS. In addition, LA-ICPMS and SIMS isotope data of B, Li, and Pb are presented

Atmospheric Dispersion Modellingof Volcanic Emissions

Gases and particles released by volcanoes pose a serious hazard to humans and society. Emis-sions can be transported over long distances before being reduced to harmless concentrations.Knowing which areas are, or will be, exposed to volcanic emissions is an important part inreducing the impact on human health or society. In this thesis, the dispersion of volcanic emis-sions is studied using a set of atmospheric models. Two case studies have been performed, onestudying potential ash emission from future eruptions on Iceland, and a second covering SO2 emissions from Mt. Nyiragongo in D.R. Congo The first study covers long range (∼1,000 km) dispersion of fine ash from explosive erup-tions. Three years of meteorological data are used to repeatedly simulate five eruption scenarios.The resulting concentrations of airborne ash at different times relative the onset of each eruptionis compared to current and previous threshold concentrations used by air traffic controllers. Theash hazard showed a seasonal variation, with a higher probability of efficient eastward transportin winter, compared to summer; summer eruptions pose a more persistent hazard. In the second study, emissions of SO2 from passive degassing at Mt. Nyiragongo is studiedover a one–year period. The meteorological impact on the dispersion is studied by assigninga fixed emission source. Furthermore, flux measurements from the remote sensing data areused to improve the description of the emission source. Gases are generally transported to thenorth-west in June–August and to the south-west in December–January. A diurnal variation dueto land breeze around lake Kivu contributes to high concentrations of SO2 along the northernshore during the night. Daily averaged concentrations in the city of Goma (∼15 km SW of thesource) exceeded the European Union’s air quality standard (125 μg/m 3 ) for 120-210 days overa one year period.Gas- och partikelutsl ̈app fr ̊an vulkaner utg ̈or en fara för människor och för vårt samhälle. Utsläppen kan transporteras över långa avstånd innan de reduceras till ofarliga halter. Att kännatill vilka områden som utsätts, eller kommer utsättas, för utsläppen är ett viktigt verktyg för att minska påverkan påv folkhälsa och samhället. I den här avhandlingen studeras spridningen av utsläpp från vulkaner med hjälp av en uppsättning atmosfärsmodeller. Två fallstudier har utförts,en fokuserar på vulkanaska från potentiella framtida utbrott på Island, den andra studerar SO2 -ustl äpp fr ̊an Nyiragongo i Demokratiska Republiken Kongo. Den f ̈orsta studien beskriver l ̊angv ̈aga (∼1,000 km) transport av aska från explosiva utbrott.Tre är av meteorologiska data används för att modellera spridningen från fem olika utbrotts-scenarier för varierande vädersituationer. Koncentrationen av luftburen aska studeras vid olikatidpunkter relativt utbrottens starttid och j ̈amf ̈ors med tidigare samt befintliga gränsvärden för flygtrafik. Sannolikheten för skadliga halter aska varierar med årstid, med en högre sannolikhetför effektiv transport österut under vintermånaderna, jämfört med sommarmånaderna; sommar-utbrott är istället mer benägna att orsaka långvariga problem över specifika områden. I den andra studien modelleras utsl ̈app av SO 2 från passiva utsläpp vid Nyiragongo över en ettårsperiod. Den meteorologiska effekten på spridningen studeras genom att använda en konatant utsläppskälla. Dessutom studeras spridningen mer i detalj genom att använda fjärranalysdata för att bättre uppskatta utsläppen. Gaserna transporteras i regel mot nordväst i juni–augusti ochmot sydväst i december–februari. En sjö-/landbriscirkulation runt Kivusjön orsakar höga halterav SO2 längs sjöns norra strand nattetid. Dygnsmedelkoncentrationer av SO2 i provinshuvud-staden Goma (∼15 km sydväst om Nyiragongo) överskred EU-riktlinjer (125 μg/m3 ) under 120-210 dagar under en ettårsperiod

Spridningsmodellering av utsläpp från vulkaner

Gases and particles released by volcanoes pose a serious hazard to humans and society. Emissions can be transported over long distances before being reduced to harmless concentrations. Knowing which areas are, or will be, exposed to volcanic emissions is an important part inreducing the impact on human health and society. In this thesis, the dispersion of volcanic emissions is studied using a set of atmospheric models. The work includes contribution to the development of the Lagrangian Particle Dispersion Model FLEXPART-WRF. Three case studies have been performed, one studying potential ash emissions from potential future eruptions on Iceland, a second covering SO2 emissions from Mt. Nyiragongo in D.R. Congo, and a third studying the SO2 emission rate of the Holuhraun eruption (Iceland) in 2014–2015. The first study covers volcanic ash hazard for air traffic over Europe. Three years of meteorological data are used to repeatedly simulate dispersion from different eruption scenarios. The simulations are used to study the probability of hazardous concentrations in ash in European airspace. The ash hazard shows a seasonal variation with a higher probability of efficient eastward transport in winter, while summer eruptions pose a more persistent hazard. In the second study, regional gas exposure around Mt. Nyiragongo is modelled using flux measurements to improve the description of the emission source. Gases are generally transported to the north-west in June–August and to the south-west in December–January. A diurnal variation due to land breeze around lake Kivu contributes to high concentrations of SO2 along the northern shore during the night. Potentially hazardous concentrations are occasionally reached in populated areas in the region, but mainly during the nights. The third study uses inverse dispersion modelling to determine the height and emission rates based on traverse measurements of the plume at 80–240 km from the source. The calculated source term yields better agreement with satellite observations compared to commonly used column sources. The work in this thesis presents improvements in dispersion modelling of volcanic emissions through improved models, more accurate representation of the source terms, and through incorporating new types of measurements into the modelling systems.Gas- och partikelutsläpp från vulkaner utgör en fara för människor och för vårt samhälle. Utsläppen kan transporteras över långa avstånd innan de reduceras till oskadliga halter. Att känna till vilka områden som utsätts för, eller kommer utsättas för, utsläppen är ett viktigt verktyg föratt minska påverkan på folkhälsa och samhälle. I avhandlingen studeras spridningen av utsläpp från vulkanutbrott med hjälp av en uppsättning numeriska atmosfärsmodeller. Den Lagrangiska Partikelspridningsmodellen FLEXPART-WRF har förbättrats och applicerats för spridningsmodellering av vulkanutbrott. Tre studier har utförts, en fokuserar på vulkanaska från potentiella framtida utbrott på Island, den andra studerar SO2-ustläpp från vulkanen Nyiragongo i Demokratiska Republiken Kongo, och den tredje studerar SO2-ustläpp från utbrottet i Holuhraun (Island) 2014–2015. Den första studien uppskattar sannolikheten för att vulkanaska från framtida vulkanutbrott på Island ska överskrida de gränsvärden som tillämpas för flygtrafik. Tre år av meteorologisk data används för att simulera spridningen från olika utbrottsscenarier. Sannolikheten för skadliga halter aska varierar med årstid, med en högre sannolikhet för effektiv transport österut under vintermånaderna, sommarutbrott är istället mer benägna att orsaka långvariga problem överspecifika områden. In den andra studien undersöks spridningen av SO2 från Nyiragongo över en ettårsperiod. Flödesmätningar av plymen används för att förbättra källtermen i modellen. Gaserna transporteras i regel mot nordväst i juni–augusti och mot sydväst i december–februari En dygnsvariation, kopplad till mesoskaliga processer runt Kivusjön, bidrar till förhöjda halter av SO2 nattetid längs Kivusjöns norra kust. Potentiellt skadliga halter av SO2 uppnås av och till i befolkade områden men huvudsakligen nattetid. Den tredje studien utnyttjar inversmodellering för att avgöra plymhöjd och gasutsläpp baserat på traversmätningar av plymen runt 80–240 km från utsläppskällan. Den beräknade källtermen resulterar i bättre överensstämmelse mellan modell- och satellitdata jämfört med enklare källtermer. Arbetet i den här avhandlingen presenterar flertalet förbättringar för spridningsmodellering av vulkanutbrott genom bättre modeller, nogrannare beskrivning av källtermer, och genom nya metoder för tillämpning av olika typer av mätdata

What are the potential economic opportunities created by climate change for the expansion of the agriculture industry on Prince Edward Island?

No matter what continent, country, state, province, city or village one considers, agriculture can flourish, be destroyed or be held prisoner by climate. Canadian agriculture can be subject to failure under disastrous climate extremes, such as droughts and flooding. Climate in the northern latitudes are believed to be the regions of the world that will benefit the most from the expected warming trends (Zilberman, D., Liu, X., Roland-Hulst, D., and Sunding, D. (2003). Currently and in the future, climate change has and will have a significant impact on the way agricultural operations are managed. Are the crop varieties being grown now, going to be available choices down the road? Will there be more value-added product choices to be grown in the future? What current crop choices would perform better with a longer growing season? With the data produced in this research it shows that as time progresses and climate change occurs, the region will have access to earlier planting dates and more heat units during the growing season. Specifically, this study shows an average increase in GSL of 30 days (or 20%) and in heat units (GDDs) of 625 by the 2020s (2011-2040). This increase in heat could potentially raise potato yields by 300cwt per acre by 2040, translating into a potential increase of $327 million gross return for the PEI potato industry; and potentially develop a$21.9 million dollar pulse industry for PEI by the year 2040