scholarly journals Rapid geomorphological and sedimentological changes at a modern Alpine ice margin: lessons from the Gepatsch Glacier, Tirol, Austria

2021 ◽  
pp. jgs2021-052
Author(s):  
Daniel Paul Le Heron ◽  
Christoph Kettler ◽  
Bethan J. Davies ◽  
Lars Scharfenberg ◽  
Lukas Eder ◽  
...  
Keyword(s):  
Sedimentary Facies ◽  
Mass Wasting ◽  
Erosion And Deposition ◽  
Content Type ◽  
Glacial Sediments ◽  
Time Period ◽  
Preservation Potential ◽  
Supplementary Material ◽  
Sand And Gravel ◽  
First Time

The Gepatsch Glacier in Tirol (Austria) is a rapidly retreating valley glacier whose host valley and forefield reveal subglacial, proglacial, and reworked sediment-landform assemblages. Structures include roches moutonées develop on gneiss, compound bedrock-sediment bedforms (crag and tail structures), flutes, and small diamicton ridges. The glacial sediments and landforms are undergoing incision and terrace development by meltwater streams. Glacial geomorphological and surface geological maps maps, in concert with elevation models of difference between July 2019 and July 2020 highlight considerable changes to the forefield over a 12-month time period. Till exposed within the last 20 years has undergone substantial mass wasting and re-deposition as subaerial mass flows, or reworked into stream deposits. The lee sides of many roches moutonées completely lack subglacial sediment, and instead contain a sand and gravel deposit interpreted to result from glaciofluvial deposition. Thus, insights into the rates of erosion and deposition in a complex, proglacial setting, allow some of these processes to be quantified for the first time. Repeated monitoring of glacier forefields is expected to yield a better understanding of the preservation potential of proglacial sedimentary facies, and hence their preservation potential in Earth's sedimentary record.Supplementary material:https://doi.org/10.6084/m9.figshare.c.5664299

The sediment-landform assemblage in the forefield of the Gepatsch Glacier, Tirol, Austria and its preservation potential

2021 ◽  
Author(s):  
Daniel Le Heron ◽  
Bethan Davies ◽  
Lars Scharfenberg ◽  
Christoph Kettler ◽  
Michael Ketterman ◽  
...  
Keyword(s):  
Sedimentary Facies ◽  
Erosion And Deposition ◽  
Glacial Sediments ◽  
Time Period ◽  
Digital Elevation ◽  
Preservation Potential ◽  
Elevation Changes ◽  
Sand And Gravel ◽  
First Time

<p>Ongoing monitoring of the Gepatsch Glacier, Tirol (Austria) consists of a multifaceted, interdisciplinary project which aims to characterise short term (diurnal in the summer melt season) and longer term (annual to decadal) changes to the glacier snout and forefield in the context of a rapid retreating valley glacier. The glacial valley and forefield comprises amphibolites, para- and orthogneisses that have been smoothed and striated into whalebacks, compound bedrock-sediment bedforms (crag and tail structures), flutes, and annual moraines. The glacial sediments and landforms are undergoing incision and terrace development by meltwater streams. As part of a long term goal to characterise the rates of erosion, sedimentation, and re-deposition, we return to the same site each year in mid-July to collect airborne data with an UAV (Mavic Pro drone) that allows us to produce orthophotos and digital elevation models. We compute the daily and annual elevation changes, allowing us determine zones of erosion and deposition. Measureable evidence for erosion of flutes in the immediate glacial forefield has occurred over a 12-month time period. Till deposited within the last 20 years has undergone substantial mass wasting and re-deposition as subaerial mass flows, or reworked into stream deposits. The lee side of many whaleback structures completely lacks subglacial sediment, and contains instead a sand and gravel deposit interpreted to result from waterlain deposition. Thus, this case study area offers insight into the rates of erosion and deposition in a complex, proglacial setting, allowing some of these processes to be quantified for the first time. This approach is expected to yield a better understanding of the preservation potential of proglacial sedimentary facies, and hence their preservation potential in Earth’s sedimentary record.</p>

The Evolution of the Popocatépetl Volcanic Complex: Constraints on Periodic Edifice Construction and Destruction by Sector Collapse

2021 ◽  
pp. jgs2021-022
Author(s):  
Guillem Gisbert ◽  
Hugo Delgado-Granados ◽  
Martin Mangler ◽  
Julie Prytulak ◽  
Ramón Espinasa-Pereña ◽  
...  
Keyword(s):  
Aerial Imagery ◽  
Volcanic Complex ◽  
Sector Collapse ◽  
Content Type ◽  
Digital Elevation ◽  
History Of ◽  
Supplementary Material ◽  
Complex Constraints ◽  
Elevation Model ◽  
First Time

Popocatépetl is one of the most active volcanoes in North America. Its current predominantly mild activity is contrasted by a history of large effusive and explosive eruptions and sector collapse events, which was first summarised by Espinasa-Pereña and Martin-Del Pozzo (2006). Since then, a wealth of new radiometric, geophysical and volcanological data has been published, requiring a re-evaluation of the evolution of the Popocatépetl Volcanic Complex (PVC). Herein, we combine existing literature with new field observations, aerial imagery and digital elevation model interpretations to produce an updated and improved reconstruction of the growth and evolution of the PVC through all of its history. This will be fundamental for the assessment and mitigation of risks associated with potential future high-magnitude activity of the PVC. The PVC consists of four successive volcanic edifices separated by three sector collapse events producing avalanche deposits: Tlamacas (>538 - >330 ka, described here for the first time), Nexpayantla (∼330 - >96 ka), Ventorrillo (∼96 ka - 23.5 ka) and Popocatépetl (<23.5ka) edifices. The newly described Tlamacas collapse propagated towards ENE forming part of the Mayorazgo avalanche deposit.Supplementary material:https://doi.org/10.6084/m9.figshare.c.5709190

Volcaniclastic deposits and sedimentation processes around volcanic ocean islands: the central Azores

2021 ◽  
pp. SP520-2021-62
Author(s):  
Yu-Chun Chang ◽  
Neil C. Mitchell ◽  
Thor H. Hansteen ◽  
Julie C. Schindlbeck-Belo ◽  
Armin Freundt
Keyword(s):  
Volcanic Glass ◽  
Sedimentary Facies ◽  
Turbidity Currents ◽  
Content Type ◽  
Core Logging ◽  
Supplementary Material ◽  
Geochemical Analyses ◽  
Lithological Composition ◽  
Volcaniclastic Deposits ◽  
Ocean Islands

AbstractGeological histories of volcanic ocean islands can be revealed by the sediments shed by them. Hence there is an interest in studying cores of volcaniclastic sediments that are particularly preserved in the many flat-floored basins lying close to the Azores islands. We analyse four gravity cores collected around the central group of the islands. Three sedimentary facies (F1-F2a, F2b) are recognized based on visual core logging, particle morphometric and geochemical analyses. F1 is clay-rich hemipelagite comprising homogeneous mud with mottled structures from bioturbation. F2a and F2b are both clay-poor volcaniclastic deposits, which are carbonate-rich and carbonate-poor, respectively. More biogenic carbonate in F2a reflects the incorporation of unconsolidated calcareous material from island shelves or bioturbation. Within F2a and F2b we identify deposits emplaced by pyroclastic fallout, primary or secondary turbidity currents by combining multiple information from lithological composition, sedimentary structures, chemical composition of volcanic glass shards and morphometric characteristics of volcanic particles. Primary volcaniclastic sediments were found in all four cores, echoing activity known to have occurred up to historical times on the adjacent islands. These preliminary results suggest that greater details of geological events could be inferred for other volcanic islands by adopting a similar approach to core analysis.Supplementary material at https://doi.org/10.6084/m9.figshare.c.5602176

Neurosurgical workforce trends in the United States

2005 ◽  
Vol 102 (2) ◽  
pp. 202-208 ◽  
Author(s):  
Oren N. Gottfried ◽  
Richard L. Rovit ◽  
A. John Popp ◽  
Kristin L. Kraus ◽  
Arlene Stolper Simon ◽  
...  
Keyword(s):  
United States ◽  
The United States ◽  
Content Type ◽  
The Past ◽  
Time Period ◽  
The Us ◽  
The Mean ◽  
First Time ◽  
Second Period ◽  
Fine Print

Object. The purpose of this study was to evaluate the US neurosurgery workforce by reviewing journal recruitment advertisements published during the past 10 years. Methods. The number of available academic and private neurosurgical staff positions was determined based on recruitment advertisements in the Journal of Neurosurgery and Neurosurgery for the 10-year period from 1994 to 2003. Advertisements were evaluated for practice venue, subspecialization, and location. The numbers of active neurosurgeons and graduating residents also were reviewed. The number of advertised neurosurgical positions increased from 141.6 ± 38.2 per year from 1994 through 1998 to 282.4 ± 13.6 per year from 1999 through 2003 (mean ± standard deviation, p < 0.05). The mean number of academic positions increased from 50.6 ± 11.1 to 95 ± 17.5 (p <0.05), and the mean number of private positions rose from 91 ± 30.4 to 187.4 ± 6.8 (p <0.05). Subspecialty positions represented a mean of only 15.6 ± 5% per year during the first time period and 18.8 ± 3% per year in the second period (p = 0.22), and therefore the majority of positions advertised continued to be those for generalists. The number of practicing neurosurgeons declined after 1998, and by 2002 it was less than it had been in 1991. The numbers of incoming and matriculating residents during the study period were static. Conclusions. The number of recruitment advertisements for neurosurgeons during the last 5 years has increased significantly, concomitant with a severe decline in the number of active neurosurgeons and a static supply of residents.

scholarly journals The palynology of the Kimmeridge Clay and Carstone formations (Upper Jurassic – Lower Cretaceous) at Middlegate Quarry, North Lincolnshire, UK, and its biostratigraphical and palaeoenvironmental significance

2021 ◽  
pp. pygs2021-005
Author(s):  
Roderick D. Black ◽  
Paul Dodsworth
Keyword(s):  
Lower Cretaceous ◽  
Upper Jurassic ◽  
Average Concentration ◽  
Dinoflagellate Cysts ◽  
Content Type ◽  
Palynological Data ◽  
Supplementary Material ◽  
Clay Formation ◽  
First Time ◽  
Lower Kimmeridgian

At Middlegate Quarry, the Carstone Formation is an approximately 0.8 m thick unit of oolitic ferruginous sandstone. It rests unconformably on the lower Kimmeridge Clay Formation (KCF) and is overlain by the Hunstanton Formation (Red Chalk) with an apparently gradational junction. Marine dinoflagellate cysts (dinocysts) are present at a concentration of 9,520 to 13,600 specimens per gramme in the 0.15 m of KCF below the unconformity, and include taxa that confirm ammonite evidence for the intra-Lower Kimmeridgian Substage (Upper Jurassic, Cymodoce Ammonite Zone). A rich recovery of well-preserved Lower Cretaceous palynomorphs is reported for the first time from the overlying Carstone. Reworking of mudstone from the KCF into the formation appears to have provided a local argillaceous preservation matrix at Middlegate. The basal 0.15 m is dominated by palynomorphs derived from the KCF but the interval from 0.15 m to 0.55 m above the unconformity mainly contains indigenous Lower Cretaceous palynomorphs. Dinoflagellate cysts are present in the Carstone at an average concentration of 454 specimens per gramme, and include taxa that probably have stratigraphical range bases above the Aptian – Albian stage boundary; Cyclonephelium compactum, Cyclonephelium intonsum, Endoscrinium heikeae, Leptodinium cancellatum (consistent), Stephodinium coronatum and Stephodinium spinulosum. The additional presence of taxa with range tops / event tops in the Lower Albian Tardefurcata Ammonite Zone (common Cauca parva, frequent Canninginopsis monile and Kleithriasphaeridium eoinodes, and rare Dingodinium albertii, Discorsia nannus and Kiokansium prolatum) indicate probable assignment to this zone. The new palynological data support previous macrofossil (brachiopod) study of the Carstone at Middlegate and nearby Melton Bottom Quarry which tentatively assigns its highest part to the Tardefurcata Zone. The palynological and palynofacies assemblages are interpreted to confirm a relatively proximal to shoreline site of deposition, possibly inner to middle neritic.Supplementary material: One pdf file, with quarry photographs and a palynological distribution chart, is available at https://doi.org/10.6084/m9.figshare.c.5538977

Serpukhovian in Britain: use of foraminiferal assemblages for dating and correlating

2020 ◽  
pp. jgs2020-170
Author(s):  
P. Cózar ◽  
I. D. Somerville
Keyword(s):  
Shallow Water ◽  
Deep Water ◽  
Content Type ◽  
South Wales ◽  
First Occurrence ◽  
Supplementary Material ◽  
First Time ◽  
Early Late ◽  
Basinal Facies ◽  
Serpukhovian Stage

Analysis of foraminiferal assemblages from the Viséan-Serpukhovian boundary interval in Britain has led to the recognition that levels correlated with the first occurrence of Lochriea ziegleri at the base of the Serpukhovian Stage can be established by the foraminifer Neoarchaediscus gregorii in England and Scotland, which first occurs from the Single Post and Cockleshell limestones in northern England and laterally equivalent levels, as well as Asteroarchaediscus bashkiricus, and A. rugosus (except for South Wales). Contrary to some previous studies, the base of the Serpukhovian does not equate with the base of the Namurian (Pendleian Substage), but lies approximately at the early-late Brigantian boundary, based on the first occurrence of Neoarchaediscus postrugosus. Four foraminiferal assemblages are distinguished in the early Serpukhovian (7-10) and four assemblages in the late Serpukhovian (11-14). Despite the contrast in facies, it is now recognised for the first time that throughout the Midland Valley of Scotland, northern England and South Wales. the foraminiferal assemblages from shallow-water platform facies are completely compatible with the ammonoid subzones from deep-water basinal facies, with no apparent mismatches. There appears to be close comparability of foraminiferal assemblages and first appearance datums of marker species with most of the international foraminiferal zonal schemes in Russia.Supplementary material:https://doi.org/10.6084/m9.figshare.c.5240408

Conference report: innovation, interaction … and a lot of data: first time reflections on Internet Librarian International, UK 2018

2019 ◽  
Vol 36 (2) ◽  
pp. 21-22
Author(s):  
Ray Harper
Keyword(s):  
Best Practice ◽  
New Technologies ◽  
Conference Report ◽  
Library Services ◽  
New Techniques ◽  
Content Type ◽  
Making A Difference ◽  
Analyse Data ◽  
Physical Spaces ◽  
First Time

Purpose The purpose of this paper is to summarise a number of presentations at Day 1 of the Internet Librarian International conference, London, UK (16 October 2018). This was the 20th conference in the series, and the three key themes included were the next-gen library and librarian; understanding users, usage and user experience; and inclusion and inspiration: libraries making a difference. Design/methodology/approach This paper reports from the viewpoint of a first-time attendee of the conference. This summarises the main issues raised by each presentation and draws out the key learning points for practical situations. Findings The conference covered a variety of practical ways in which libraries can use technology to support users and make decisions about services. These include developing interactive physical spaces which include augmented reality; introducing “chat-bots” to support users; using new techniques to analyse data; and piloting new ways to engage users (such as coding clubs). A key theme was how we use and harness data in a way that is ethical, effective and relevant to library services. Originality/value This conference focussed on practical examples of how library and information services across sectors and countries are innovating in a period of huge change. The conference gave delegates numerous useful ideas and examples of best practice and demonstrated the strength of the profession in adapting to new technologies and developments.

Interest rate option hedging portfolios without bank account

2019 ◽  
Vol 37 (1) ◽  
pp. 134-142
Author(s):  
Alberto Bueno-Guerrero
Keyword(s):  
Design Methodology ◽  
Contingent Claim ◽  
Necessary And Sufficient Condition ◽  
Barrier Option ◽  
Bank Account ◽  
Content Type ◽  
Option Hedging ◽  
Hedging Portfolio ◽  
Necessary And Sufficient ◽  
First Time

Purpose This paper aims to study the conditions for the hedging portfolio of any contingent claim on bonds to have no bank account part. Design/methodology/approach Hedging and Malliavin calculus techniques recently developed under a stochastic string framework are applied. Findings A necessary and sufficient condition for the hedging portfolio to have no bank account part is found. This condition is applied to a barrier option, and an example of a contingent claim whose hedging portfolio has a bank account part different from zero is provided. Originality/value To the best of the authors’ knowledge, this is the first time that this issue has been addressed in the literature.

A “Learning from Action” workshop in Japan

2019 ◽  
Vol 40 (2) ◽  
pp. 77-83
Author(s):  
Robert Douglas Hinshelwood ◽  
Luca Mingarelli ◽  
Simona Masnata
Keyword(s):  
Far East ◽  
Opportunity To Learn ◽  
Content Type ◽  
Work Activities ◽  
Defensive Role ◽  
Feedback Data ◽  
Experiential Workshop ◽  
First Time ◽  
Practical Implications

Purpose Many people in severe mentally disturbed states do not use language or other symbolic media well or coherently. Therefore, the non-verbal medium needs to be understood by workers with such people. The “Learning from Action” experiential workshop was developed in order to provide an opportunity to learn about hidden messages in the relationships and roles occurring in activities. In August 2017, a workshop was run for the first time in Japan. The purpose of this paper is to report the experience and dynamics observed by the three consultants, who are here the authors of this paper. Design/methodology/approach After the workshop all the staff and members, including interpreters, were invited to give feedback. Findings Analysis of the feedback data showed certain important dynamics, concerning especially dependence, cultural defences and the defensive role of activity in a multicultural context. Research limitations/implications This is an initial experience to be followed up by later feedback and further workshops. Practical implications Workers awareness of non-verbal communication within the roles of work activities is a training possibility. It faces various resistances including the mental health assumptions of meaninglessness of any communication outside the verbal. Originality/value This is a method of training not widely used even in European countries, and is the first in a country in the far east.

Whirling in between the personal and the impersonal

2019 ◽  
Vol 25 (2) ◽  
pp. 257-284
Author(s):  
Armen E. Petrosyan
Keyword(s):  
Organization Theory ◽  
Conceptual Analysis ◽  
Essential Elements ◽  
Organizational Life ◽  
Critical Perspective ◽  
Content Type ◽  
Organizational Goals ◽  
Last Stage ◽  
First Time ◽  
Current Paradigm

Purpose The paper aims to present a systematic conceptual analysis of the problem of organizational goal and to reduce the insights into it provided by the main conceptions taken in their development from one to another, to break out of the ruling paradigm and outline a new solution. Design/methodology/approach The study has been carried out from the historical and critical perspective. Findings The paper discovers the logic of the evolution the approaches to organizational goals have undergone and portrays it in a matrix form in the heart of which is the “zigzag effect”: each posterior stage returns to the essential elements rejected by those preceding it, and the last stage, being diametrically opposite to the first, is, at that, as well as the latter, akin to the intermediate stages. The opportunities afforded by the current paradigm have been exhausted and it seems to run to an impasse. Instead, the author suggests a new frame of orientation: organizational goals are closely interknit with personal, but not reducible to them and bear fundamentally transpersonal character, while the mechanism of involving the preferences of individuals and groups in goal-setting is based on the self-contained interests of the organization they pertain to. Research limitations/implications The findings, conclusions and generalizations obtained can serve for a necessary ground to researchers getting deeper into the essence of what bonds organizational life and activity. Practical implications The material empowers practitioners to comprehend the difficulties of framing cohesive goal and find efficient ways to overcome them. It is of value also to the teachers seeking to present a more exact and elaborate view of teleological foundations of management and organization theory. Originality/value Both the conceptual analysis of the evolution of the approaches to organizational goals and the author’s exposition of its logic and vision of their nature are provided for the first time.

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