Contemporary geomorphological activity throughout the proglacial area of an alpine catchment

Quantification of contemporary geomorphological activity is a fundamental prerequisite for predicting the effects of future earth surface process and landscape development changes. However, there is a lack of high-resolution spatial and temporal data on geomorphological activity within alpine catchments, which are especially sensitive to climate change, human impacts and which are amongst the most dynamic landscapes on Earth. This study used data from repeated laser scanning to identify and quantify the distribution of contemporary sediment sources and the intensity of geomorphological activity within the lower part of a glaciated alpine catchment; Ödenwinkelkees, central Austria. Spatially, geomorphological activity was discriminated by substrate class. Activity decreased in both areal extent and intensity with distance from the glacier, becoming progressively more restricted to the fluvially-dominated valley floor. Temporally, geomorphological activity was identified on annual, seasonal, weekly and daily timescales. Activity became more extensive with increasing study duration but more intense over shorter timescales, thereby demonstrating the importance of temporary storage of sediment within the catchment. The mean volume of material moved within the proglacial zone was 4400m.yr, which suggests a net surface lowering of 34mm.yr in this part of the catchment. We extrapolate a minimum of 4.8mm.yr net surface lowering across the whole catchment. These surface lowering values are approximately twice those calculated elsewhere from contemporary measurements of suspended sediment flux, and of rates calculated from the geological record, perhaps because we measure total geomorphological activity within the catchment rather than overall efflux of material. Repeated geomorphological surveying therefore appears to mitigate the problems of hydrological studies underestimating sediment fluxes on decadal-annual time-scales. Further development of the approach outlined in this study will enable the quantification of geomorphological activity, alpine terrain stability and persistence of landforms

An advanced model for initiation and propagation of damage under fatigue loading - part II: Matrix cracking validation cases

A series of tests were conducted to act as validation cases for the numerical model developed in part I of this paper to predict the initiation and propagation of damage in composite materials. The onset of matrix cracking in [0(2)/0(4)](s) specimens under tension-tension fatigue loading was studied using acoustic emission (AE) and dye-penetrant enhanced X-rays. The number of cracks identified by significant AE hits correlated well with the number of cracks identified by X-rays. Finite Element simulations of the [0(2)/0(4)](s) specimens using the model from part I for cohesive interface elements fatigue loading showed a good correlation with the experimental results

Periglacial disruption and subsequent glacitectonic deformation of bedrock : an example from Anglesey, North Wales, UK

The deformed metasedimentary bedrock and overlying diamictons in western Anglesey, NW Wales, record evidence of glacier-permafrost interactions during the Late Devensian (Weichselian). The locally highly brecciated New Harbour Group bedrock is directly overlain by a bedrock-rich diamicton which preserves evidence of having undergone both periglacial (brecciation, hydrofracturing) and glacitectonic deformation (thrusting, folding), and is therefore interpreted as periglacial head deposit. The diamicton locally posses a well-developed clast macrofabric which preserves the orientation of the pre-existing tectonic structures within underlying metasedimentary rocks. Both the diamicton and New Harbour Group were variably reworked during the deposition of the later Irish Sea diamicton, resulting in the detachment of bedrock rafts and formation of a pervasively deformed glacitectonite. These structural and stratigraphic relationships are used to demonstrate that a potentially extensive layer of permafrost developed across the island before it was overridden by the Irish Sea Ice Stream. These findings have important implications for the glacial history of Anglesey, indicating that the island remained relatively ice-free prior to its inundation by ice flowing southwards down the Irish Sea Basin. Palynological data obtained from the diamictons across Anglesey clearly demonstrates that they have an Irish Sea provenance. Importantly no Lower Palaeozoic palynomorphs were identified, indicating that it is unlikely that Anglesey was overridden by ice emanating from the Snowdon ice cap developed on the adjacent Welsh mainland. Permafrost was once again re-established across Anglesey after the Irish Sea Ice Stream had retreated, resulting in the formation of involutions which deform both the lower bedrock-rich and overlying Irish Sea diamictons. � 2012 Natural Environment Research Council. Published by Elsevier Ltd on behalf of The Geologists’ Association. All rights reserved

Data and results for manuscript "Imaging groundwater infiltration dynamics in karst vadose zone with long-term ERT monitoring"

This data set contains raw and inverted data from an Electrical Resistivity Tomography (ERT) monitoring experiment conducted over a period of three years at the Rochefort Cave Laboratory (RCL) site in South Belgium. It highlights variable hydrodynamics in the karst vadose zone of Lorette Cave. More conventional hydrological measurements (drip discharge monitoring, soil moisture and water conductivity data sets) are also included in the package, which aims at provide a thorough understanding of the groundwater infiltration. Seasonal changes affect all the imaged areas leading to increases in resistivity in spring/summer attributed to enhanced evapotranspiration, whereas winter is characterised by a general decrease in resistivity associated with a groundwater recharge of the vadose zone. This study provides detailed images of the sources of drip discharge spots traditionally monitored in caves and aims to support modelling approaches of karst hydrological processes

Assessing the Impact of the COVID-19 Pandemic on Emergency Department Use for Patients Undergoing Cancer-Directed Surgeries

Emergency department (ED) use is a concern for surgery patients, physicians and health administrators particularly during a pandemic. The objective of this study was to assess the impact of the pandemic on ED use following cancer-directed surgeries. This is a retrospective cohort study of patients undergoing cancer-directed surgeries comparing ED use from 7 January 2018 to 14 March 2020 (pre-pandemic) and 15 March 2020 to 27 June 2020 (pandemic) in Ontario, Canada. Logistic regression models were used to (1) determine the association between pandemic vs. pre-pandemic periods and the odds of an ED visit within 30 days after discharge from hospital for surgery and (2) to assess the odds of an ED visit being of high acuity (level 1 and 2 as per the Canadian Triage and Acuity Scale). Of our cohort of 499,008 cancer-directed surgeries, 468,879 occurred during the pre-pandemic period and 30,129 occurred during the pandemic period. Even though there was a substantial decrease in the general population ED rates, after covariate adjustment, there was no significant decrease in ED use among surgical patients (OR 1.002, 95% CI 0.957–1.048). However, the adjusted odds of an ED visit being of high acuity was 23% higher among surgeries occurring during the pandemic (OR 1.23, 95% CI 1.14–1.33). Although ED visits in the general population decreased substantially during the pandemic, the rate of ED visits did not decrease among those receiving cancer-directed surgery. Moreover, those presenting in the ED post-operatively during the pandemic had significantly higher levels of acuity