45 research outputs found
Rock temperature variability in the alpine cryosphere
No full textIn a context of cryosphere degradation caused by climate warming, rock temperature is one of the main driving factors of rockfalls that occur on high-elevation mountain slopes. In order to improve the knowledge of this critical relationship, it is necessary to increase measurement capability of rock temperature and its variability in different lithological and slope/aspect conditions, and also to increase local scale studies, increasing the quality and the comparability of the data. Rock temperature data, acquired from July 2018 to July 2022 in an alpine experimental glacial basin (https://deims.org/f8718e56-fb4d-49a3-92a9-3670e7f10ee9), in different two temperature monitoring sites (TMS) with the same lithological conditions (calc-schists) but in two different aspect conditions (South and North), at an elevation range from 2653 to 2667 m a.s.l, are present. The temperature data have been acquired by using six MadgeTech MicroTemp Data Logger (MT), metrologically referenced and with known measurement uncertainty (0.098 °C)
Rock and debris temperature in the alpine cryosphere
No full textMore than 218,000 rock and debris temperature data, acquired from July 2016 to August 2018 in an alpine experimental glacial basin, in different 12 measurement sites (MS) with different lithological and slope/aspect conditions, at an elevation range from 2600 to 2800 m a.s.l, are present. The temperature data have been acquired by using 10 MadgeTech MicroTemp Data Logger (MT), metrologically referenced and with known measurement uncertainty (0.098 °C)
Climatic conditions associated to the occurrence of slope instabilities in the Italian Alps in year 2016
No full textStudies carried out in different parts of the world have shown that, in the mountain high-elevation sites, temperature can play a major role in the preparation and trigger of slope instabilities. However, the interplay with other climatic parameters (in particular precipitation) and the nature of the climate-driven processes that lead to the development of slope instability continue to be poorly understood. This understanding is crucial in order to define reliable scenarios of the evolution of slope instability under the expected climatic and environmental changes. The present work aims to contribute to shed light on these issues by analyzing with the statistical and probabilistic method developed by Paranunzio et al. (2016) the values of the climatic parameters associated to the most significant events of slope instability occurred at high elevation in the Italian Alps in 2016. The method allows to detect the anomalies in temperature and precipitation values that are associated to the development of these slope instabilities, providing the ground for discussion of possible causes and triggering mechanisms, also in the framework of ongoing climate change. Paranunzio R., Laio F., Chiarle M., Nigrelli G., Guzzetti F. (2016) - Climate anomalies associated to the occurrence of rockfalls at high-elevation in the Italian Alps. Natural Hazards and Earth System Sciences, 16, 2085-2106, DOI: 10.5194/nhess-16-2085-2016
Recent slope failures in the Dolomites (Northeastern Italian Alps) in a context of climate change
No full textRock temperature variability in high-altitude rockfall-prone areas
No full textIn a context of cryosphere degradation caused by climate warming, rock temperature is one of the main driving factors of rockfalls that occur on high-elevation mountain slopes. In order to improve the knowledge of this critical relationship, it is necessary to increase measurement capability of rock temperature and its variability in different lithological and slope/aspect conditions, and also to increase local scale studies, increasing the quality and the comparability of the data. This paper shows an example of metrological characterization of sensors used for rock temperature measurement in mountain regions, by means of the measurement uncertainty. Under such approach, data and results from temperature measurements carried out in the Bessanese high-elevation experimental site (Western European Alps) are illustrated. The procedures for the calibration and field characterization of sensors allow to measure temperature in different locations, depths and lithotypes, within 0.10 °C of overall uncertainty. This work has highlighted that metrological traceability is fundamental to asses data quality and establish comparability among different measurements; that there are strong differences between air temperature and near-surface rock temperature; and that there are significant differences of rock temperature acquired in different aspect conditions. Finally, solar radiation, slope/aspect conditions and lithotype, seem to be the main driving factors of rock temperature
Assessment of risk factors for rupture in breast reconstruction patients with macrotextured breast implants
No full textBackground: Breast implants (BI) are widely used in plastic surgery, though they are not lifetime devices. Average life before rupture is reportedto be around 10-15 years. No consensus exists regarding which factors are involved.Objectives: Following FDA recommendations, this study aims at identifying potential risk factors by evaluating their effect on BI rupture cases.Methods: In this observational study, 763 BI patients were operated between 2003 and 2019, with a mean implant indwelling of 12.2 years. Patients that returned for follow-up were administered a questionnaire regarding postoperative lifestyle and habits. Implant rupture rate was 15.1%, while BI lifespan was 10.1 years. We obtained complete data from 191 breast implant patients (288 implants). Twenty-three potential risk factors were evaluated and divided in four categories: patient-related, surgery-related, postoperative complications/symptoms, and postoperative care/lifestyle habits. Odds Ratio (OR) for each factor was calculated. Linear regression analysis was calculated for those with a significant OR.Results: We report 120 patients (195 implants) with intact and 71 (93 implants) with ruptured devices. BIs were macrotextured in 95.1% of cases (86.8% Allergan BIOCELL). OR was significant for underwire bra use (OR: 2.708), car seat belts (OR: 3.066), mammographic imaging (OR: 2.196), weightlifting (OR: 0.407) and carry-on heavy purses and backpacks (OR: 0.347).Conclusion: Wearing underwire bras, seat belts and undergoing mammography increases the risk of rupture. Weightlifting and carry heavy bags do not increase that risk. Implant rupture is directly linked with time of indwelling. Postoperative recommendations in BI patients should consider findings from our study, though larger multicenter studies should be encouraged
Climate anomalies associated with the occurrence of rockfalls at high-elevation in the Italian Alps
No full textClimate change is seriously affecting the cryosphere in
terms, for example, of permafrost thaw, alteration of rain ∕ snow ratio, and
glacier shrinkage. There is concern about the increasing number of rockfalls
at high elevation in the last decades. Nevertheless, the exact role of
climate parameters in slope instability at high elevation has not been fully
explored yet. In this paper, we investigate 41 rockfalls listed in different
sources (newspapers, technical reports, and CNR IRPI archive) in the
elevation range 1500–4200 m a.s.l. in the Italian Alps between 1997 and 2013
in the absence of an evident trigger. We apply and improve an existing
data-based statistical approach to detect the anomalies of climate
parameters (temperature and precipitation) associated with rockfall
occurrences. The identified climate anomalies have been related to the
spatiotemporal distribution of the events. Rockfalls occurred in
association with significant temperature anomalies in 83 % of our case
studies. Temperature represents a key factor contributing to slope failure
occurrence in different ways. As expected, warm temperatures accelerate
snowmelt and permafrost thaw; however, surprisingly, negative anomalies are
also often associated with slope failures. Interestingly, different regional
patterns emerge from the data: higher-than-average temperatures are often
associated with rockfalls in the Western Alps, while in the Eastern Alps slope
failures are mainly associated with colder-than-average temperatures
The importance of using sensors with known measurement uncertainty at high-elevation sites: the freeze-thaw cycles
No full textNew insights in the relation between climate and slope failures at high-elevation sites
No full textClimate change is now unequivocal; however, the type and extent of terrestrial impacts are still widely debated. Among these, the effects on slope stability are receiving a growing attention in recent years, both as terrestrial indicators of climate change and implications for hazard assessment. High-elevation areas are particularly suitable for these studies, because of the presence of the cryosphere, which is particularly sensitive to climate. In this paper, we analyze 358 slope failures which occurred in the Italian Alps in the period 2000–2016, at an elevation above 1500 m a.s.l. We use a statistical-based method to detect climate anomalies associated with the occurrence of slope failures, with the aim to catch an eventual climate signal in the preparation and/or triggering of the considered case studies. We first analyze the probability values assumed by 25 climate variables on the occasion of a slope-failure occurrence. We then perform a dimensionality reduction procedure and come out with a set of four most significant and representative climate variables, in particular heavy precipitation and short-term high temperature. Our study highlights that slope failures occur in association with one or more climate anomalies in almost 92% of our case studies. One or more temperature anomalies are detected in association with most case studies, in combination or not with precipitation (47% and 38%, respectively). Summer events prevail, and an increasing role of positive temperature anomalies from spring to winter, and with elevation and failure size, emerges. While not providing a final evidence of the role of climate warming on slope instability increase at high elevation in recent years, the results of our study strengthen this hypothesis, calling for more extensive and in-depth studies on the subject
Freeze-thaw cycles in the rocks of the Bessanese experimental site (Western Alps, Italy)
No full textFreeze-thaw action induces both rock weathering and mass wasting, destabilizing rock and debris slopes in high mountain regions. Matsuoka, in 1990, defines an Effective Freeze-Thaw Cycle (EFTC) as a fall below -2 °C of the rock surface temperature followed by a rise above +2 °C. Rock temperatures in alpine environments are strongly influenced by slope inclination, slope aspect, local topoclimatic conditions (including seasonal snow cover), and thermal properties of the rock. Our main objectives are: to investigate rock and air temperature variability in an instrumented site at high elevation in the Western Alps of Italy, to identify rockfall events occurred in the monitorin
