scholarly journals Mid-crustal storage and crystallization of Eyjafjallajökull ankaramites, South Iceland

JOKULL ◽  
2020 ◽  
Vol 69 ◽  
pp. 83-102
Author(s):  
Paavo Nikkola ◽  
Enik˝o Bali ◽  
Maren Kahl ◽  
Quinten H. A. van der Meer ◽  
O. Tapani Rämö ◽  
...  
Keyword(s):  
Melt Inclusions ◽  
Chromian Spinel ◽  
Large Temperature ◽  
Magma Storage ◽  
Short Period ◽  
Magnesian Olivine ◽  
Mg Melt ◽  
Crustal Magma ◽  
Eruptive Behaviour

Our understanding of the long-term intrusive and eruptive behaviour of volcanic systems is hampered by a relatively short period of direct observation. To probe the conditions of crustal magma storage below South Iceland, we have analysed compositions of minerals, mineral zoning patterns, and melt inclusions from two Eyjafjallajökull ankaramites located at Brattaskjól and Hvammsmúli. These two units are rich in compositionally diverse macrocrysts, including the most magnesian olivine (Fo88-90) and clinopyroxene (Mg#cpx 89.8) known from Eyjafjallajökull. Olivine-hosted spinel inclusions have high Cr#spl (52–80) and TiO2 (1–3 wt%) and low Al2O3 (8–22 wt%) compared to typical Icelandic chromian spinel. The spinel-olivine oxybarometer implies a moderate oxygen fugacity of logFMQ 0–0.5 at the time of crystallization, and clinopyroxene-liquid thermobarometry crystallization at mid-crustal pressures (1.7–4.2 kbar, 3.0±1.4 kbar on average) at 1120–1195°C. Liquid-only thermometry for melt inclusions with Mg#melt 56.1–68.5 and olivine-liquid thermometry for olivine macrocrysts with Fo80.7-88.9 yield crystallization temperatures of 1155–1222°C and 1136–1213°C, respectively. Diffusion modelling of compositional zonations in the Brattaskjól olivine grains imply that the Brattaskjól macrocrysts were mobilized and transported to the surface from their mid-crustal storage within a few weeks (at most in 9–37 days). Trends in clinopyroxene macrocryst compositions and the scarcity of plagioclase indicate that the mid-crustal cotectic assemblage was olivine and clinopyroxene, with plagioclase joining the fractionating mineral assemblage later. In all, the crystal cargoes in the Brattaskjól and Hvammsmúli ankaramites are composed of agitated wehrlitic or plagioclase wehrlitic crystal mushes that crystallized over a large temperature interval at mid-crustal depths.

scholarly journals Downward-propagating eruption following vent unloading implies no direct magmatic trigger for the 2018 lateral collapse of Anak Krakatau

2021 ◽  
Author(s):  
Kyra Cutler ◽  
Sebastian Watt ◽  
Mike Cassidy ◽  
Amber Madden-Nadeau ◽  
Samantha Engwell ◽  
...  
Keyword(s):  
Storage System ◽  
Magma Ascent ◽  
Magma Storage ◽  
Highly Sensitive ◽  
Short And Long Term ◽  
Krakatau Volcano ◽  
Deformation Patterns ◽  
Crustal Magma ◽  
Increased Susceptibility

The lateral collapse of Anak Krakatau volcano, Indonesia, in December 2018 highlighted the potentially devastating impacts of volcanic edifice instability. Nonetheless, the trigger for the Anak Krakatau collapse remains obscure. The volcano had been erupting for the previous six months, and although failure was followed by intense explosive activity, it is the period immediately prior to collapse that is potentially key in providing identifiable, pre-collapse warning signals. Here, we integrate physical, microtextural and geochemical characterisation of tephra deposits spanning the collapse period. We demonstrate that the first post-collapse eruptive phase (erupting juvenile clasts with a low microlite areal number density and relatively large microlites, reflecting a crystal-growth dominated regime) is best explained by instantaneous unloading of a relatively stagnant upper conduit. This was followed by the second post-collapse phase, on a timescale of hours, which tapped successively hotter and deeper magma batches, reflected in increasing plagioclase anorthite content and more mafic glass compositions, alongside higher calculated ascent velocities and decompression rates. The characteristics of the post-collapse products imply downward propagating destabilisation of the magma storage system as a response to collapse, rather than pre- collapse magma ascent triggering failure. Importantly, this suggests that the collapse was a consequence of longer-term processes linked to edifice growth and instability, and that no indicative changes in the magmatic system could have signalled the potential for incipient failure. Therefore, monitoring efforts may need to focus on integrating short- and long-term edifice growth and deformation patterns to identify increased susceptibility to lateral collapse. The post-collapse eruptive pattern also suggests a magma pressurisation regime that is highly sensitive to surface-driven perturbations, which led to elevated magma fluxes after the collapse and rapid edifice regrowth. Not only does rapid regrowth potentially obscure evidence of past collapses, but it also emphasises the finely balanced relationship between edifice loading and crustal magma storage.

scholarly journals Management of a Mycotic Aneurysm in a Patient with COVID-19: A Case Report

Medicina ◽  
2021 ◽  
Vol 57 (6) ◽  
pp. 620
Author(s):  
Muzammil H. Syed ◽  
Mark Wheatcroft ◽  
Danny Marcuzzi ◽  
Hooman Hennessey ◽  
Mohammad Qadura
Keyword(s):  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Stent Graft ◽  
Mycotic Aneurysm ◽  
Neurological Deficits ◽  
Endovascular Stent ◽  
Endovascular Stents ◽  
Abdominal Aortic ◽  
Short Period

The aim of this paper is to share our experience in managing a patient with Klebsiella pneumoniae mycotic abdominal aortic aneurysm who was also infected with COVID-19. A 69-year-old male was transferred to our hospital for the management of an infra-renal mycotic abdominal aortic aneurysm. During his hospital course, the patient contracted severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). He was intubated due to respiratory distress. Over a short period, his mycotic aneurysm increased in size from 2.5 cm to 3.9 cm. An emergency repair of his expanding aneurysm was achieved using our previously described protocol of coating endovascular stents with rifampin. The patient was managed with a rifampin-coated endovascular stent graft without any major complications. Postoperatively, the patient did not demonstrate any neurological deficits nor any vascular compromise. He remained afebrile during his postoperative course and was extubated sometime thereafter. He was then transferred to the ward for additional monitoring prior to his discharge to a rehab hospital while being on long-term antibiotics. During his hospital stay, he was monitored with serial ultrasounds to ensure the absence of abscess formation, aortic aneurysm growth or graft endoleak. At 6 weeks after stent graft placement, he underwent a CT scan, which showed a patent stent graft, with a residual sac size of 2.5 cm without any evidence of abscess or endoleak. Over a follow-up period of 180 days, the patient remained asymptomatic while remaining on long-term antibiotics. Thus, in patients whose surgical risk is prohibitive, endovascular stent grafts can be used as a bridge to definitive surgical management.

scholarly journals An unusually low density ultra-short period super-Earth and three mini-Neptunes around the old star TOI-561

2020 ◽  
Author(s):  
G Lacedelli ◽  
L Malavolta ◽  
L Borsato ◽  
G Piotto ◽  
D Nardiello ◽  
...  
Keyword(s):  
Transit Time ◽  
Time Variation ◽  
Planetary System ◽  
Radial Velocities ◽  
Low Density ◽  
Outer Planets ◽  
Short Period ◽  
The Stability

Abstract Based on HARPS-N radial velocities (RVs) and TESS photometry, we present a full characterisation of the planetary system orbiting the late G dwarf After the identification of three transiting candidates by TESS, we discovered two additional external planets from RV analysis. RVs cannot confirm the outer TESS transiting candidate, which would also make the system dynamically unstable. We demonstrate that the two transits initially associated with this candidate are instead due to single transits of the two planets discovered using RVs. The four planets orbiting TOI-561 include an ultra-short period (USP) super-Earth (TOI-561 b) with period Pb = 0.45 d, mass Mb = 1.59 ± 0.36 M⊕ and radius Rb = 1.42 ± 0.07 R⊕, and three mini-Neptunes: TOI-561 c, with Pc = 10.78 d, Mc = 5.40 ± 0.98 M⊕, Rc = 2.88 ± 0.09 R⊕; TOI-561 d, with Pd = 25.6 d, Md = 11.9 ± 1.3 M⊕, Rd = 2.53 ± 0.13 R⊕; and TOI-561 e, with Pe = 77.2 d, Me = 16.0 ± 2.3 M⊕, Re = 2.67 ± 0.11 R⊕. Having a density of 3.0 ± 0.8 g cm−3, TOI-561 b is the lowest density USP planet known to date. Our N-body simulations confirm the stability of the system and predict a strong, anti-correlated, long-term transit time variation signal between planets d and e. The unusual density of the inner super-Earth and the dynamical interactions between the outer planets make TOI-561 an interesting follow-up target.

scholarly journals Heatwaves in Kenya 1987–2016: Facts from CHIRTS High Resolution Satellite Remotely Sensed and Station Blended Temperature Dataset

Atmosphere ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 37
Author(s):  
Martial Amou ◽  
Amatus Gyilbag ◽  
Tsedale Demelash ◽  
Yinlong Xu
Keyword(s):  
High Resolution ◽  
Adaptation Strategies ◽  
Reference Period ◽  
The West ◽  
Tana River ◽  
Short Period ◽  
The World ◽  
Northern Side ◽  
Data Source

As global temperatures continue to rise unabated, episodes of heat-related catastrophes across the world have intensified. In Kenya, heatwave phenomena and their associated impacts are ignored and neglected due to several reasons, including unreliable and inconsistent weather datasets and heatwave detection metrics. Based on CHIRTS satellite infrared estimates and station blended temperature, this study investigated the spatiotemporal distribution of the heatwave events over Kenya during 1987–2016 using the Heatwave Magnitude Index daily (HWMId). The results showed that contrary to the absence of heatwave records in official national and international disaster database about Kenya, the country experienced heatwaves ranging from less severe (normal) to deadly (super-extreme) between 1987 and 2016. The most affected areas were located in the eastern parts of the country, especially in Garissa and Tana River, and in the west-northern side around the upper side of Turkana county. It was also found that the recent years’ heatwaves were more severe in magnitude, duration, and spatial extent. The highest magnitude of the heatwaves was recorded in 2015 (HWMId = 22.64) while the average over the reference period is around 6. CHIRTS and HWMId were able to reveal and capture most critical heatwave events over the study period. Therefore, they could be used respectively as data source and detection metrics, for heatwaves disaster emergency warning over short period as well as for long-term projection to provide insight for adaptation strategies.

Long-term efficacy of a short period of taping followed by an exercise program in a cohort of patients with patellofemoral pain syndrome

2011 ◽  
Vol 31 (3) ◽  
pp. 535-539 ◽  
Author(s):  
Marco Paoloni ◽  
Giancarlo Fratocchi ◽  
Massimiliano Mangone ◽  
Massimiliano Murgia ◽  
Valter Santilli ◽  
...  
Keyword(s):  
Exercise Program ◽  
Pain Syndrome ◽  
Patellofemoral Pain Syndrome ◽  
Patellofemoral Pain ◽  
Term Efficacy ◽  
Short Period

scholarly journals The Crustal Magma Storage System of Volcán Quizapu, Chile, and the Effects of Magma Mixing on Magma Diversity

2012 ◽  
Vol 53 (4) ◽  
pp. 801-840 ◽  
Author(s):  
Philipp Ruprecht ◽  
George W. Bergantz ◽  
Kari M. Cooper ◽  
Wes Hildreth
Keyword(s):  
Magma Mixing ◽  
Storage System ◽  
Magma Storage ◽  
Crustal Magma

scholarly journals Long-term development of short-period gravity waves in middle Europe

2011 ◽  
Vol 116 ◽  
Author(s):  
D. Offermann ◽  
J. Wintel ◽  
C. Kalicinsky ◽  
P. Knieling ◽  
R. Koppmann ◽  
...  
Keyword(s):  
Gravity Waves ◽  
Short Period ◽  
Middle Europe

scholarly journals TRENDS IN DATA WAREHOUSING TECHNIQUES

2021 ◽  
Author(s):  
Naveen Kunnathuvalappil Hariharan
Keyword(s):  
Relational Databases ◽  
Financial Data ◽  
Relational Model ◽  
Time Data ◽  
Short Period ◽  
The Subject ◽  
Processing And Storage ◽  
And Storage ◽  
Long Term Trend

Financial data volumes are increasing, and this appears to be a long-term trend, implying that data managementdevelopment will be crucial over the next few decades. Because financial data is sometimes real-time data, itis constantly generated, resulting in a massive amount of financial data produced in a short period of time.The volume, diversity, and velocity of Big Financial Data are highlighting the significant limitations oftraditional Data Warehouses (DWs). Their rigid relational model, high scalability costs, and sometimesinefficient performance pave the way for new methods and technologies. The majority of the technologiesused in background processing and storage research were previously the subject of research in their earlystages. The Apache Foundation and Google are the two most important initiatives. For dealing with largefinancial data, three techniques outperform relational databases and traditional ETL processing: NoSQL andNewSQL storage, and MapReduce processing.

scholarly journals Change and Continuity in Vaping and Smoking by Young People: A Qualitative Case Study of a Friendship Group

2018 ◽  
Author(s):  
Neil McKeganey ◽  
Marina Barnard
Keyword(s):  
Young People ◽  
Electronic Cigarettes ◽  
Cigarette Use ◽  
Friendship Group ◽  
Quantitative And Qualitative Research ◽  
Short Period ◽  
Actual Use ◽  
Substantial Change

This paper explores as a case study the development of e-cigarette use and smoking within small friendship group (n=8) in Glasgow, Scotland. Interviewed twice at six months apart these 16/17 year olds reported substantial change in their use of and attitudes towards e-cigarettes and tobacco. At time 1 vaping generated much excitement and interest, with 6/8 having their own vape device. At time 2 only two young people still vaped, with the others no longer professing any interest in continued vaping. The two regular smokers, who had been smoking before they first vaped, now only vaped privately and to reduce their tobacco intake. This small case study illustrates plasticity in the use of electronic cigarettes; just as young people can initiate using these devices so too can they more away from their use- with such changes in actual use occurring within a relatively short period of time. These findings demonstrate more than anything else the volatility in young peoples’ substance use behaviour. If we are to better understand these behaviours we require both quantitative and qualitative research studies that are capable of both monitoring changes in individual and group behaviour over time but which are also able to elucidate the nuance of individual behaviour differentiating between long term, frequent, consistent use and more episodic, experimental and infrequent use by young people.

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